JP7166594B2

JP7166594B2 - Mo-Si-Ti-C-based alloy and method for producing Mo-Si-Ti-C-based alloy

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Publication number: JP7166594B2
Application number: JP2018125809A
Authority: JP
Inventors: 享祐吉見; 詩歩鎌田; 基行束村; 俊一中山; 琢也黄金崎; 友孝畠山
Original assignee: Tohoku University NUC
Current assignee: Tohoku University NUC
Priority date: 2018-07-02
Filing date: 2018-07-02
Publication date: 2022-11-08
Anticipated expiration: 2038-07-02
Also published as: JP2020002451A

Description

特許法第３０条第２項適用・発行者名：公益社団法人日本金属学会刊行物名：２０１８年春期講演大会（第１６２回）日本金属学会講演大会概要集発行年月日：２０１８年（平成３０年）３月５日・集会名：日本金属学会２０１８年春期（第１６２回）講演大会開催日：２０１８年（平成３０年）３月１９日～２１日Application of Article 30, Paragraph 2 of the Patent Act Publisher name: The Japan Institute of Metals Publication name: 2018 Spring Lecture Meeting (162nd) Summary of the Japan Institute of Metals Lecture Meeting Publication date: 2018 March 5, 2018 Name of meeting: 2018 Spring (162nd) Lecture Meeting of the Japan Institute of Metals Date: March 19-21, 2018

本発明は、Ｍｏ－Ｓｉ－Ｔｉ－Ｃ系合金およびＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法に関する。 The present invention relates to a Mo--Si--Ti--C alloy and a method for producing a Mo--Si--Ti--C alloy.

ジェットエンジンやガスタービンなどの熱機関を高効率で運転させるために、無冷却で使用可能な超高温材料が求められている。そのような材料として、従来から、高い融点および優れた高温強度を有するＭｏ－Ｓｉ－Ｂ合金が注目されているが、高密度であり、室温破壊靭性に劣るという問題があった。そこで、本発明者等は、Ｍｏ－Ｓｉ－Ｂ合金にＴｉＣを添加した合金を開発し、この合金が、Ｍｏ－Ｓｉ－Ｂ合金の優れた高温強度を維持したまま、Ｍｏ－Ｓｉ－Ｂ合金より低密度で、室温破壊靭性が高いことを確認している（例えば、特許文献１、２、非特許文献１乃至３参照）。 In order to operate heat engines such as jet engines and gas turbines with high efficiency, ultra-high temperature materials that can be used without cooling are required. Mo--Si--B alloys, which have a high melting point and excellent high-temperature strength, have been attracting attention as such materials. Therefore, the present inventors have developed an alloy in which TiC is added to a Mo-Si-B alloy, and this alloy maintains the excellent high-temperature strength of the Mo-Si-B alloy. It has been confirmed that the density is lower and the fracture toughness at room temperature is higher (see, for example, Patent Documents 1 and 2 and Non-Patent Documents 1 to 3).

国際公開ＷＯ２０１４／１１２１５１号International publication WO2014/112151 特許第５８７６９４３号公報Japanese Patent No. 5876943

山本詩歩、吉見享祐、金正旭、横山健太郎、「TiC添加したMo-Si-B合金の高温強度に及ぼすミクロ組織の影響」、日本金属学会誌、2016年、第80巻、第1号、p.51-59Shiho Yamamoto, Kyosuke Yoshimi, Jeong Wook Kim, Kentaro Yokoyama, "Effect of microstructure on high-temperature strength of TiC-added Mo-Si-B alloy", Journal of Japan Institute of Metals, Vol.80, No.1, 2016, p.51-59 Kyosuke Yoshimi, Junya Nakamura, Daiki Kanekon, Shiho Yamamoto, Kouichi Maruyama, Hirokazu Katsui, Takashi Goto, “High-Temperature Compressive Properties of TiC-Added Mo-Si-B Alloys”, JOM, 2014, 66(9), p.1930-1938Kyosuke Yoshimi, Junya Nakamura, Daiki Kanekon, Shiho Yamamoto, Kouichi Maruyama, Hirokazu Katsui, Takashi Goto, “High-Temperature Compressive Properties of TiC-Added Mo-Si-B Alloys”, JOM, 2014, 66(9), p. 1930-1938 Shimpei Miyamoto, Kyosuke Yoshimi, Seong-Ho Ha, Takahiro Kaneko, Junya Nakamura, Tetsuya Sato, Kouichi Maruyama, Rong Tu, Takashi Goto, “Phase Equilibria, Microstructure, and High Temperature Strength of TiC-Added Mo-Si-B Alloys”, Metallurgical and Materials Transactions A, 2014, 45A, p.1112-1123Shimpei Miyamoto, Kyosuke Yoshimi, Seong-Ho Ha, Takahiro Kaneko, Junya Nakamura, Tetsuya Sato, Kouichi Maruyama, Rong Tu, Takashi Goto, “Phase Equilibria, Microstructure, and High Temperature Strength of TiC-Added Mo-Si-B Alloys” , Metallurgical and Materials Transactions A, 2014, 45A, p.1112-1123

特許文献１等に記載のＴｉＣを添加したＭｏ－Ｓｉ－Ｂ系合金は、優れた高温強度を有しており、ジェットエンジンやガスタービンの高圧タービン翼としての応用が期待されている。高圧タービン翼として応用する場合、高圧タービン翼とタービンディスクとの接合部では摺動摩擦が発生すると考えられるため、長寿命化を見据えると、高温強度だけでなく、摺動摩擦時の温度下（約７００～８００℃）での耐酸化性についても、常に向上が求められている。 Mo--Si--B alloys to which TiC is added, such as those described in Patent Document 1, have excellent high-temperature strength and are expected to be applied as high-pressure turbine blades for jet engines and gas turbines. When applied as a high-pressure turbine blade, it is thought that sliding friction occurs at the joint between the high-pressure turbine blade and the turbine disk. There is also a constant demand for improved oxidation resistance at temperatures up to 800°C.

本発明は、このような課題に着目してなされたもので、少なくとも８００℃程度までの優れた耐酸化性を有するＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金およびＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法を提供することを目的とする。 The present invention has been made with a focus on such problems, and provides Mo—Si—Ti—C alloys and Mo—Si—Ti—C alloys having excellent oxidation resistance up to at least about 800° C. The object is to provide a manufacturing method.

上記目的を達成するために、本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌとから成り、前記Ｍｏを２８原子％以上６０原子％以下、前記Ｓｉを１．７原子％以上２０．０原子％以下、前記Ｔｉを５．０原子％以上４２．０原子％以下、前記Ｃを４．０原子％以上１５．０原子％以下、前記Ｃｒと前記Ａｌとを合わせて２．０原子％以上２５．０原子％以下で含んでいることを特徴とする。また、本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌと、Ｂとから成り、前記Ｍｏを２８原子％以上６０原子％以下、前記Ｓｉを１．７原子％以上２０．０原子％以下、前記Ｔｉを５．０原子％以上４２．０原子％以下、前記Ｃを４．０原子％以上１５．０原子％以下、前記Ｃｒと前記Ａｌとを合わせて２．０原子％以上２５．０原子％以下、前記Ｂを３．３原子％以上１３．３原子％以下で含んでいてもよい。 In order to achieve the above object, the Mo—Si—Ti—C alloy according to the present invention comprises Mo, Si, Ti, C, Cr and/or Al, and contains 28 atomic % of Mo. 60 atomic % or more, 1.7 atomic % or more and 20.0 atomic % or less of Si, 5.0 atomic % or more and 42.0 atomic % or less of Ti, and 4.0 atomic % or more and 15.0 atomic % of C It is characterized by containing 2.0 atomic % or more and 25.0 atomic % or less of the Cr and the Al together . Further, the Mo-Si-Ti-C alloy according to the present invention comprises Mo, Si, Ti, C, Cr and/or Al, and B, and the Mo is 28 atomic% or more and 60 atoms % or less, the Si content of 1.7 atomic % or more and 20.0 atomic % or less, the Ti content of 5.0 atomic % or more and 42.0 atomic % or less, and the C content of 4.0 atomic % or more and 15.0 atomic % or less. , the Cr and the Al may be 2.0 atomic % or more and 25.0 atomic % or less in total, and the B may be 3.3 atomic % or more and 13.3 atomic % or less .

本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌとから成り、前記Ｍｏを２８原子％以上６０原子％以下、前記Ｓｉを１．７原子％以上２０．０原子％以下、前記Ｔｉを５．０原子％以上４２．０原子％以下、前記Ｃを４．０原子％以上１５．０原子％以下、前記Ｃｒと前記Ａｌとを合わせて２．０原子％以上２５．０原子％以下で含んでいる原料を、溶解して鋳造することを特徴とする。また、本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌと、Ｂとから成り、前記Ｍｏを２８原子％以上６０原子％以下、前記Ｓｉを１．７原子％以上２０．０原子％以下、前記Ｔｉを５．０原子％以上４２．０原子％以下、前記Ｃを４．０原子％以上１５．０原子％以下、前記Ｃｒと前記Ａｌとを合わせて２．０原子％以上２５．０原子％以下、前記Ｂを３．３原子％以上１３．３原子％以下で含んでいる原料を、溶解して鋳造してもよい。 The method for producing a Mo—Si—Ti—C alloy according to the present invention comprises Mo, Si, Ti, C, Cr and/or Al, and the Mo content is 28 atomic % or more and 60 atomic % or less. , the Si content of 1.7 atomic % or more and 20.0 atomic % or less, the Ti content of 5.0 atomic % or more and 42.0 atomic % or less, the C content of 4.0 atomic % or more and 15.0 atomic % or less, the A raw material containing 2.0 atomic % or more and 25.0 atomic % or less of Cr and Al in total is melted and cast. In addition, the method for producing a Mo—Si—Ti—C alloy according to the present invention comprises Mo, Si, Ti, C, Cr and/or Al, and B, and the Mo content is 28 atomic %. 60 atomic % or more, 1.7 atomic % or more and 20.0 atomic % or less of Si, 5.0 atomic % or more and 42.0 atomic % or less of Ti, and 4.0 atomic % or more and 15.0 atomic % of C A raw material containing 2.0 atomic % or more and 25.0 atomic % or less of said Cr and 25.0 atomic % or less of said B, and 3.3 atomic % or more and 13.3 atomic % or less of said B is melted. may be cast.

本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、ＣｒおよびＡｌを含んでいないＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金と比べて、少なくとも８００℃程度までの耐酸化性に優れている。また、ＣｒおよびＡｌを含んでいないＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金と比べて、軽量であると共に、硬い。本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金を好適に製造することができる。本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、いわゆる鋳造法を利用するため、製造されるＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金を大型化することができる。 The Mo--Si--Ti--C alloy according to the present invention is superior in oxidation resistance up to at least about 800.degree. It is also lighter and harder than Mo--Si--Ti--C alloys that do not contain Cr and Al. The method for producing a Mo--Si--Ti--C alloy according to the present invention can suitably produce the Mo--Si--Ti--C alloy according to the present invention. Since the method for producing a Mo--Si--Ti--C alloy according to the present invention uses a so-called casting method, it is possible to increase the size of the produced Mo--Si--Ti--C alloy.

本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金および本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、前記Ｍｏを２８原子％以上６０原子％以下、前記Ｓｉを１．７原子％以上２０．０原子％以下、前記Ｔｉを５．０原子％以上４２．０原子％以下、前記Ｃを４．０原子％以上１５．０原子％以下、前記Ｃｒと前記Ａｌとを合わせて２．０原子％以上２５．０原子％以下で含んでいることが好ましい。この場合、Ｔｉが４２．０原子％より多いとき、Ｓｉが２０．０原子％より多いとき、または、ＣｒとＡｌとを合わせた量が２５．０原子％より多いときには、高温強度が低下しはじめるため、これらの成分は、それぞれの上限値よりも少ないことが好ましい。また、耐酸化性および高温強度を高めるため、ＣｒとＡｌとを合わせた量は、２．０原子％以上であることが好ましい。 The Mo--Si--Ti--C alloy according to the present invention and the method for producing the Mo--Si--Ti--C alloy according to the present invention contain 28 atomic % or more and 60 atomic % or less of Mo and 1.7 atomic % of Si. atomic % or more and 20.0 atomic % or less, said Ti of 5.0 atomic % or more and 42.0 atomic % or less, said C of 4.0 atomic % or more and 15.0 atomic % or less, said Cr and said Al combined 2.0 atomic % or more and 25.0 atomic % or less. In this case, when Ti is more than 42.0 atomic %, when Si is more than 20.0 atomic %, or when the combined amount of Cr and Al is more than 25.0 atomic %, the high-temperature strength decreases. To begin with, it is preferred that these components be less than their respective upper limits. Also, in order to increase oxidation resistance and high-temperature strength, the total amount of Cr and Al is preferably 2.0 atomic % or more.

また、この場合、前記Ｃｒと前記Ａｌとを合わせて５．５原子％以上２５．０原子％以下であってもよく、また、前記Ｓｉが１．７原子％以上６．７原子％以下、前記Ｔｉが５．０原子％以上２５．０原子％以下、前記Ｃｒが１２．０原子％以上２３．０原子％以下であってもよい。また、前記Ｓｉが１．７原子％以上６．７原子％以下、前記Ｔｉが１２．０原子％以上３０．０原子％以下、前記Ａｌが２．０原子％以上７．０原子％以下であってもよい。また、前記Ｓｉが１０．０原子％以上２０．０原子％以下、前記Ｔｉが２３．０原子％以上４２．０原子％以下、前記Ｃｒが４．５原子％以上１３．０原子％以下であってもよい。また、Ｂを３．３原子％以上１３．３原子％以下で含んでいてもよい。これらの場合、特に耐酸化性に優れている。また、優れた高温強度も有している。 In this case, the Cr and the Al may be 5.5 atomic percent or more and 25.0 atomic percent or less in total, and the Si content is 1.7 atomic percent or more and 6.7 atomic percent or less, The Ti may be 5.0 atomic % or more and 25.0 atomic % or less, and the Cr may be 12.0 atomic % or more and 23.0 atomic % or less. The Si content is 1.7 atomic % or more and 6.7 atomic % or less, the Ti content is 12.0 atomic % or more and 30.0 atomic % or less, and the Al content is 2.0 atomic % or more and 7.0 atomic % or less. There may be. The Si content is 10.0 atomic % or more and 20.0 atomic % or less, the Ti content is 23.0 atomic % or more and 42.0 atomic % or less, and the Cr content is 4.5 atomic % or more and 13.0 atomic % or less. There may be. Also, B may be contained in an amount of 3.3 atomic % or more and 13.3 atomic % or less. In these cases, they are particularly excellent in oxidation resistance. It also has excellent high temperature strength.

本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、鋳造後、１５００℃～１９００℃で１時間～１２０時間の均質化熱処理を行うことが好ましい。この場合、均質化熱処理により、耐酸化性や高温強度、破壊靭性を向上させることができる。 In the method for producing a Mo--Si--Ti--C alloy according to the present invention, it is preferable to perform homogenization heat treatment at 1500° C. to 1900° C. for 1 hour to 120 hours after casting. In this case, the homogenization heat treatment can improve oxidation resistance, high-temperature strength, and fracture toughness.

本発明に係るＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、ジェットエンジンやガスタービンの高圧タービン動静翼だけでなく、高温鋳造金型や、摩擦撹拌接合用ツール等の、高温で使用されたときに高強度が必要とされる部材に使用することができる。 The Mo-Si-Ti-C-based alloy according to the present invention is used at high temperatures not only for high-pressure turbine moving and stationary blades of jet engines and gas turbines, but also for high-temperature casting molds and tools for friction stir welding. It can be used for members that require high strength.

本発明によれば、少なくとも８００℃程度までの優れた耐酸化性を有するＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金およびＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法を提供することができる。 According to the present invention, it is possible to provide a Mo--Si--Ti--C alloy and a method for producing a Mo--Si--Ti--C alloy having excellent oxidation resistance up to at least about 800.degree.

本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の（ａ）比較試料１、（ｂ）試料１、（ｃ）試料２、（ｄ）試料３の走査型電子顕微鏡（ＳＥＭ）写真である。Scanning type of (a) comparative sample 1, (b) sample 1, (c) sample 2, and (d) sample 3 of the Mo—Si—Ti—C alloy according to the embodiment of the present invention before homogenization heat treatment It is an electron microscope (SEM) photograph. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の試料１～３および比較試料１の（ａ）７００℃、（ｂ）８００℃での酸化試験結果を示すグラフである。Mo-Si-Ti-C alloy according to the embodiment of the present invention shows oxidation test results at (a) 700 ° C. and (b) 800 ° C. for samples 1 to 3 before homogenization heat treatment and comparative sample 1. graph. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、図２に示す各試料の（ａ）７００℃（上段）および８００℃（下段）での酸化試験後の外観、（ｂ）７００℃（上段）および８００℃（下段）での酸化試験後の断面の観察結果を示す写真である。Mo-Si-Ti-C-based alloy according to the embodiment of the present invention, (a) Appearance after oxidation test at 700 ° C. (upper) and 800 ° C. (lower) of each sample shown in FIG. 2, (b) It is the photograph which shows the observation result of the cross section after the oxidation test at 700 degreeC (upper stage) and 800 degreeC (lower stage). 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、図３（ｂ）に示す（ａ）７００℃、（ｂ）８００℃での酸化試験後の各試料の、基材（酸化していない部分）の厚さの減少量ΔＬを示すグラフである。The substrate (oxidized 10 is a graph showing the amount of decrease ΔL in the thickness of the portion not covered). 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の（ａ）試料２、（ｂ）試料５、（ｃ）試料７、（ｄ）試料９、（ｅ）比較試料１、（ｆ）比較試料２の走査型電子顕微鏡（ＳＥＭ）写真である。(a) sample 2, (b) sample 5, (c) sample 7, (d) sample 9, and (e) of the Mo—Si—Ti—C alloy according to the embodiment of the present invention before homogenization heat treatment FIG. 10 is a scanning electron microscope (SEM) photograph of Comparative Sample 1 and (f) Comparative Sample 2. FIG. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の（ａ）試料２、（ｂ）試料５、（ｃ）試料７、（ｄ）試料９、（ｅ）比較試料１、（ｆ）比較試料２の走査型電子顕微鏡（ＳＥＭ）写真である。(a) Sample 2, (b) Sample 5, (c) Sample 7, (d) Sample 9, and (e) of the Mo—Si—Ti—C alloy according to the embodiment of the present invention after homogenization heat treatment FIG. 10 is a scanning electron microscope (SEM) photograph of Comparative Sample 1 and (f) Comparative Sample 2. FIG. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の（ａ）Ｔｉ＋Ｃｒ改質型の試料１～３、５、６および比較試料１、（ｂ）Ｔｉ＋Ａｌ改質型の試料７～１２および比較試料１の、ビッカース硬さ（Ｈｖ）を示すグラフである。(a) Ti + Cr modified type samples 1 to 3, 5, 6 and comparative sample 1, (b) Ti + Al modified after homogenization heat treatment of Mo-Si-Ti-C-based alloy according to the embodiment of the present invention 1 is a graph showing the Vickers Hardness (Hv) of Mold Samples 7-12 and Comparative Sample 1. FIG. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の（ａ）Ｔｉ＋Ｃｒ改質型の試料１～６、比較試料１およびＮｉ基単結晶超合金「ＴＭＳ－１３８」、（ｂ）Ｔｉ＋Ａｌ改質型の試料７～１２、比較試料１およびＮｉ基単結晶超合金「ＴＭＳ－１３８」の、密度を示すグラフである。(a) Ti + Cr modified type samples 1 to 6, comparative sample 1 and Ni-based single crystal superalloy "TMS-138" after homogenization heat treatment of Mo-Si-Ti-C alloy according to the embodiment of the present invention ”, (b) densities of Ti+Al modified samples 7 to 12, comparative sample 1 and Ni-based single crystal superalloy “TMS-138”. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の（ａ）試料１３、（ｂ）試料４、（ｃ）試料５、（ｄ）試料６の走査型電子顕微鏡（ＳＥＭ）写真である。Scanning electrons of (a) sample 13, (b) sample 4, (c) sample 5, and (d) sample 6 of the Mo—Si—Ti—C alloy according to the embodiment of the present invention before homogenization heat treatment It is a microscope (SEM) photograph. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の（ａ）試料４～６、１３および比較試料２、（ｂ）（ａ）の縦軸を拡大した試料５および６の、酸化試験結果を示すグラフである。(a) Samples 4 to 6, 13 and Comparative Sample 2 before homogenization heat treatment of the Mo—Si—Ti—C-based alloy according to the embodiment of the present invention, (b) A sample in which the vertical axis of (a) is enlarged 5 and 6 are graphs showing oxidation test results. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、酸化試験後の（ａ）比較試料２、（ｂ）試料１３、（ｃ）試料４、（ｄ）試料５、（ｅ）試料６の、断面の顕微鏡写真である。(a) Comparative sample 2, (b) sample 13, (c) sample 4, (d) sample 5, and (e) of the Mo—Si—Ti—C alloy according to the embodiment of the present invention after the oxidation test 3 is a micrograph of a cross section of Sample 6. FIG. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、酸化試験後の試料５の、エネルギー分散型Ｘ線分光法（ＳＥＭ－ＥＤＸ）による（ａ）反射電子像（ＢＳＥ像）、（ｂ）Ｍｏ、（ｃ）Ｏ、（ｄ）Ｓｉ、（ｅ）Ｔｉ、（ｆ）Ｃｒの元素マッピングである。(a) Backscattered electron image (BSE image) of Mo—Si—Ti—C alloy according to the embodiment of the present invention, sample 5 after oxidation test, by energy dispersive X-ray spectroscopy (SEM-EDX); Elemental mapping of (b) Mo, (c) O, (d) Si, (e) Ti, and (f) Cr. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、酸化試験後の試料６の、エネルギー分散型Ｘ線分光法（ＳＥＭ－ＥＤＸ）による（ａ）反射電子像（ＢＳＥ像）、（ｂ）Ｍｏ、（ｃ）Ｏ、（ｄ）Ｓｉ、（ｅ）Ｔｉ、（ｆ）Ｃｒの元素マッピングである。Energy dispersive X-ray spectroscopy (SEM-EDX) of sample 6 of the Mo—Si—Ti—C alloy according to the embodiment of the present invention after oxidation test (a) backscattered electron image (BSE image), Elemental mapping of (b) Mo, (c) O, (d) Si, (e) Ti, and (f) Cr. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、１６００℃で１０時間の均質化熱処理後の（ａ）試料４、（ｂ）試料５、（ｃ）試料６、１６００℃で１００時間の均質化熱処理後の（ｄ）試料４、（ｅ）試料５、（ｆ）試料６の走査型電子顕微鏡（ＳＥＭ）写真である。(a) Sample 4, (b) Sample 5, (c) Sample 6 after homogenization heat treatment at 1600 ° C. for 10 hours of the Mo-Si-Ti-C alloy according to the embodiment of the present invention, at 1600 ° C. 4 is a scanning electron microscope (SEM) photograph of (d) sample 4, (e) sample 5, and (f) sample 6 after homogenization heat treatment for 100 hours. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、１６００℃で１００時間の均質化熱処理後の試料５および６の、（ａ）７００℃、８００℃および９００℃で８時間の酸化試験結果、（ｂ）８００℃で１００時間の酸化試験結果、（ｃ）１６００℃で１０時間、および、１６００℃で１００時間の均質化熱処理後の試料５および６の、８００℃で８時間の酸化試験結果を示すグラフである。Samples 5 and 6 of the Mo-Si-Ti-C alloy according to the embodiment of the present invention after homogenization heat treatment at 1600°C for 100 hours: (a) 700°C, 800°C and 900°C for 8 hours (b) Oxidation test results at 800° C. for 100 hours; (c) Samples 5 and 6 after homogenization heat treatment at 1600° C. for 10 hours and 1600° C. for 8 hours at 800° C. It is a graph showing the oxidation test results of. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の試料５および比較試料１、２の、高温圧縮試験結果を示すグラフである。5 is a graph showing hot compression test results of sample 5 and comparative samples 1 and 2 after homogenization heat treatment of the Mo—Si—Ti—C alloy according to the embodiment of the present invention. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の（ａ）比較試料３、（ｂ）試料１４、（ｃ）試料１５の走査型電子顕微鏡（ＳＥＭ）写真である。Scanning electron microscope (SEM) photographs of (a) Comparative sample 3, (b) Sample 14, and (c) Sample 15 of the Mo—Si—Ti—C alloy according to the embodiment of the present invention before homogenization heat treatment is. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の（ａ）比較試料３、（ｂ）試料１４、（ｃ）試料１５の走査型電子顕微鏡（ＳＥＭ）写真である。Scanning electron microscope (SEM) photographs of (a) Comparative sample 3, (b) Sample 14, and (c) Sample 15 of the Mo—Si—Ti—C alloy according to the embodiment of the present invention after homogenization heat treatment is. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の試料１４、１５および比較試料１、３の、密度を示すグラフである。4 is a graph showing densities of samples 14 and 15 and comparative samples 1 and 3 of the Mo--Si--Ti--C alloy according to the embodiment of the present invention after homogenization heat treatment. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理後の試料１４、１５および比較試料１、３の、（ａ）８００℃、（ｂ）１１００℃での酸化試験結果を示すグラフである。Oxidation test at (a) 800 ° C. and (b) 1100 ° C. of Mo-Si-Ti-C-based alloys of the embodiment of the present invention, samples 14 and 15 after homogenization heat treatment and comparative samples 1 and 3 It is a graph which shows a result. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の試料１６の走査型電子顕微鏡（ＳＥＭ）写真である1 is a scanning electron microscope (SEM) photograph of sample 16 before homogenization heat treatment of a Mo--Si--Ti--C alloy according to an embodiment of the present invention. 本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の、均質化熱処理前の試料１６および比較試料４の、各温度での酸化試験結果を示すグラフである。4 is a graph showing oxidation test results at each temperature of sample 16 and comparative sample 4 before homogenization heat treatment of the Mo--Si--Ti--C alloy according to the embodiment of the present invention.

以下、実施例等に基づいて、本発明の実施の形態について説明する。
本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌとを有している。 BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on examples and the like.
A Mo--Si--Ti--C alloy according to an embodiment of the present invention contains Mo, Si, Ti, C, Cr and/or Al.

本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法により好適に製造される。すなわち、本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法は、Ｍｏと、Ｓｉと、Ｔｉと、Ｃと、Ｃｒおよび／またはＡｌとを有する原料を溶解して鋳造する。その後、必要に応じて、１５００℃～１９００℃で１時間～１２０時間の均質化熱処理を行う。これにより、本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金を製造することができる。 The Mo--Si--Ti--C alloy according to the embodiment of the invention is preferably produced by the method for producing the Mo--Si--Ti--C alloy according to the embodiment of the invention. That is, in the method for producing a Mo—Si—Ti—C alloy according to the embodiment of the present invention, a raw material containing Mo, Si, Ti, C, Cr and/or Al is melted and cast. . After that, if necessary, a homogenization heat treatment is performed at 1500° C. to 1900° C. for 1 hour to 120 hours. As a result, the Mo--Si--Ti--C alloy according to the embodiment of the present invention can be produced.

本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金は、ＣｒおよびＡｌを含んでいないＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金と比べて、少なくとも８００℃程度までの耐酸化性に優れている。また、ＣｒおよびＡｌを含んでいないＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金と比べて、軽量であると共に、硬い。また、鋳造法を利用して製造されるため、大型化することができる。 The Mo—Si—Ti—C alloy according to the embodiment of the present invention is superior in oxidation resistance up to at least about 800° C. as compared with the Mo—Si—Ti—C alloy that does not contain Cr and Al. there is It is also lighter and harder than Mo--Si--Ti--C alloys that do not contain Cr and Al. Moreover, since it is manufactured using a casting method, it can be made large.

本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の製造方法により、本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の試料を製造した。また、本発明の実施の形態のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金の配合とは異なる合金の試料についても、同様の方法で製造した。まず、各試料について、表１に示す配合の原料を、アルゴン雰囲気中で、アーク溶解により溶解して水冷銅鋳型に鋳造した。鋳塊の大きさは、φ４５ｍｍ、１００ｇである。鋳造後、アルゴン雰囲気中で均質化熱処理を行った。また、比較のため、表１に示すＣｒおよびＡｌを含まない比較試料のＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金も、同様の方法で製造した。 A sample of the Mo--Si--Ti--C alloy according to the embodiment of the invention was produced by the method for producing a Mo--Si--Ti--C alloy according to the embodiment of the invention. Also, a sample of an alloy having a composition different from that of the Mo--Si--Ti--C alloy according to the embodiment of the present invention was produced in the same manner. First, each sample was melted by arc melting in an argon atmosphere, and cast into a water-cooled copper mold. The size of the ingot is φ45 mm and 100 g. After casting, a homogenization heat treatment was performed in an argon atmosphere. For comparison, a comparative sample Mo--Si--Ti--C alloy containing neither Cr nor Al shown in Table 1 was also produced in the same manner.

［Ｃｒを含むＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金について］
表１に示す試料１～３および比較試料１について、均質化熱処理前の走査型電子顕微鏡（ＳＥＭ）による観察を行った。各試料のＳＥＭ写真を図１に示す。図１（ｂ）～（ｄ）に示すように、Ｃｒを含む試料１～３（55Mo-10Cr-10Ti-5Si-10C-10B、50Mo-15Cr-10Ti-5Si-10C-10B、45Mo-20Cr-10Ti-5Si-10C-10B）の合金では、Ｍｏ_ｓｓ［Ｍｏ固溶体］相、Ｔ_２［Ｍｏ_５ＳｉＢ_２］相、ＴｉＣ相、および、σ相の４相が存在していることが確認された。また、図１（ａ）に示すように、Ｃｒを含まない比較試料１（65Mo-10Ti-5Si-10C-10B（1st gen. MoSiBTiC合金））の合金では、Ｍｏ_ｓｓ、Ｔ_２、ＴｉＣ、および、Ｍｏ_２Ｃの４相が存在していることが確認された。 [About Mo-Si-Ti-C alloy containing Cr]
Samples 1 to 3 and Comparative Sample 1 shown in Table 1 were observed with a scanning electron microscope (SEM) before the homogenization heat treatment. A SEM photograph of each sample is shown in FIG. As shown in FIGS. 1(b) to (d), samples 1 to 3 containing Cr (55Mo-10Cr-10Ti-5Si-10C-10B, 50Mo-15Cr-10Ti-5Si-10C-10B, 45Mo-20Cr- _10Ti _- 5Si-10C-10B), it was confirmed that there are _four phases: Moss [Mo solid solution] phase, T2 [ _Mo5SiB2 ] phase, TiC phase, and σ phase. . In addition, as shown in FIG. 1(a), the alloy of comparative sample 1 (65Mo-10Ti-5Si-10C-10B (1st gen. MoSiBTiC alloy)) containing no Cr has Mo _ss , T ₂ , TiC, and , Mo ₂ C were confirmed to exist.

試料１～３および比較試料１について、酸化試験を行った。酸化試験では、各試料を、４×３×０．５ｍｍ^３の直方体に加工し、Ａｒ４０ｍｌ／ｍｉｎ－Ｏ_２１０ｍｌ／ｍｉｎ雰囲気中に、７００℃または８００℃で１２時間放置して酸化させた。熱重量分析（ＴＧＡ）により、酸化前後の各試料の質量の変化（Mass Change）Δｍを測定し、その結果を図２（ａ）および（ｂ）に示す。また、酸化後の各試料の外観および断面の観察結果を、それぞれ図３（ａ）および（ｂ）に示す。また、図３（ｂ）から、酸化後の各試料の基材（酸化していない部分）の厚さの減少量（Substrate Reduction）ΔＬを求め、その結果を図４（ａ）および（ｂ）に示す。 Samples 1-3 and Comparative Sample 1 were subjected to an oxidation test. In the oxidation test, each sample was processed into a rectangular parallelepiped of 4×3×0.5 mm ³ and left in an atmosphere of Ar 40 ml/min—O ₂ 10 ml/min at 700° C. or 800° C. for 12 hours for oxidation. The mass change Δm of each sample before and after oxidation was measured by thermogravimetric analysis (TGA), and the results are shown in FIGS. 2(a) and 2(b). 3(a) and 3(b) respectively show the appearance and cross-sectional observation results of each sample after oxidation. Also, from FIG. 3(b), the amount of reduction in the thickness of the substrate (non-oxidized portion) of each sample after oxidation (Substrate Reduction) ΔL was obtained, and the results are shown in FIGS. 4(a) and (b). shown in

図２～図４に示すように、７００℃および８００℃の場合ともに、Ｃｒ濃度の上昇に伴って、酸化による質量変化が小さくなることが確認された。すなわち、図２に示すように、試料１（55Mo-10Cr-10Ti-5Si-10C-10B）の合金では、質量の減少が比較試料１と同程度であることが確認された。また、試料２（50Mo-15Cr-10Ti-5Si-10C-10B）および試料３（45Mo-20Cr-10Ti-5Si-10C-10B）の合金では、比較試料１よりも顕著に質量変化が小さく、耐酸化性に優れていることが確認された。また、図３（ａ）に示すように、７００℃および８００℃の場合ともに、Ｃｒを含む試料１～３の合金では、比較試料１と比べて、外観にはほとんど変化は認められなかった。また、図３（ｂ）および図４に示すように、試料１の合金では、表層部分の酸化が比較試料１ほどではないことが確認された。また、試料２および試料３の合金では、８００℃での試料２の両端部が僅かに酸化しているだけで、その他の表層部分には酸化がほとんど認められず、基材の厚さの減少量も非常に小さく、耐酸化性に優れていることが確認された。 As shown in FIGS. 2 to 4, both at 700° C. and 800° C., it was confirmed that as the Cr concentration increased, the mass change due to oxidation decreased. That is, as shown in FIG. 2, it was confirmed that the alloy of sample 1 (55Mo-10Cr-10Ti-5Si-10C-10B) had a mass decrease comparable to that of comparative sample 1. In addition, in the alloys of sample 2 (50Mo-15Cr-10Ti-5Si-10C-10B) and sample 3 (45Mo-20Cr-10Ti-5Si-10C-10B), the mass change is significantly smaller than that of comparative sample 1, and the acid resistance is It was confirmed that the sintering property was excellent. In addition, as shown in FIG. 3(a), the alloys of Samples 1 to 3 containing Cr showed almost no change in appearance compared to Comparative Sample 1 at both 700° C. and 800° C. Moreover, as shown in FIGS. 3(b) and 4, it was confirmed that the alloy of sample 1 was not as oxidized as the comparative sample 1 in the surface layer portion. In addition, in the alloys of Samples 2 and 3, both ends of Sample 2 at 800 ° C. were only slightly oxidized, and almost no oxidation was observed in the other surface layers, and the thickness of the base material was reduced. It was confirmed that the amount was also very small and the oxidation resistance was excellent.

［ＣｒまたはＡｌを含むＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金について］
表１の試料１～１２および比較試料１、２について、均質化熱処理前後の走査型電子顕微鏡（ＳＥＭ）による観察を行った。試料２、５、７、９および比較試料１、２の、均質化熱処理前のＳＥＭ写真を図５に、均質化熱処理後のＳＥＭ写真を図６に示す。図５（ａ）および（ｂ）に示すように、均質化熱処理前は、Ｃｒを添加した試料２（50Mo-15Cr-10Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、σの４相が存在しており、試料５（40Mo-15Cr-20Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｃｒ_３Ｓｉの４相が存在していることが確認された。また、試料１、３（55Mo-10Cr-10Ti-5Si-10C-10B、45Mo-20Cr-10Ti-5Si-10C-10B）については、試料２と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、σの４相が存在しており、試料４、６（45Mo-10Cr-20Ti-5Si-10C-10B、35Mo-20Cr-20Ti-5Si-10C-10B）については、試料５と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｃｒ_３Ｓｉの４相が存在していることが確認された。 [Mo-Si-Ti-C alloy containing Cr or Al]
Samples 1 to 12 and Comparative Samples 1 and 2 in Table 1 were observed with a scanning electron microscope (SEM) before and after the homogenization heat treatment. SEM photographs of Samples 2, 5, 7 and 9 and Comparative Samples 1 and 2 before the homogenization heat treatment are shown in FIG. 5, and SEM photographs after the homogenization heat treatment are shown in FIG. As shown in FIGS. 5(a) and (b), before the homogenization heat treatment, the Cr-added sample 2 (50Mo-15Cr-10Ti-5Si-10C-10B) had Mo _ss , T ₂ , (Ti, There are four phases of Mo)C and σ, and sample 5 (40Mo-15Cr _- 20Ti-5Si-10C-10B) has four _phases of Moss, T2, (Ti, Mo)C and _Cr3Si . was confirmed to exist. As for Samples 1 and 3 (55Mo-10Cr-10Ti-5Si-10C-10B, 45Mo-20Cr-10Ti-5Si-10C-10B), Mo _ss , T ₂ , (Ti, Mo ) There are four phases of C and σ. , Mo _ss , T ₂ , (Ti, Mo)C, and Cr ₃ Si.

また、図５（ｃ）および（ｄ）に示すように、均質化熱処理前は、Ａｌを添加した試料７（57Mo-15Ti-5Si-3Al-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）の４相が存在しており、試料９（52Mo-20Ti-5Si-3Al-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）、ＭｏＡｌの５相が存在していることが確認された。また、試料８（55Mo-15Ti-5Si-5Al-10C-10B）については、試料７と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）の４相が存在しており、試料１０～１２（50Mo-20Ti-5Si-5Al-10C-10B、47Mo-25Ti-5Si-3Al-10C-10B、45Mo-25Ti-5Si-5Al-10C-10B）については、試料９と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）、ＭｏＡｌの５相が存在していることが確認された。 Further, as shown in FIGS. 5(c) and (d), before the homogenization heat treatment, the Al-added sample 7 (57Mo-15Ti-5Si-3Al-10C-10B) had Mo _ss , T ₂ , ( There are four phases of Ti, Mo)C, _Mo3 (Al, Si), and in sample 9 (52Mo- _20Ti -5Si-3Al-10C _- 10B), Moss, T2, (Ti, Mo) It was confirmed that five phases of C, Mo ₃ (Al, Si), and MoAl were present. As for sample 8 (55Mo-15Ti-5Si-5Al-10C-10B), similarly to sample 7, four phases of Mo _ss , T ₂ , (Ti, Mo)C, and Mo ₃ (Al, Si) exists, and for samples 10-12 (50Mo-20Ti-5Si-5Al-10C-10B, 47Mo-25Ti-5Si-3Al-10C-10B, 45Mo-25Ti-5Si-5Al-10C-10B), sample 9, it was confirmed that five phases of Mo _ss , T ₂ , (Ti, Mo)C, Mo ₃ (Al, Si) and MoAl were present.

また、図５（ｅ）および（ｆ）に示すように、ＣｒもＡｌも添加していない合金の場合、均質化熱処理前は、比較試料１（65Mo-10Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、（Ｍｏ、Ｔｉ）_２Ｃの４相が存在しており、比較試料２（55Mo-20Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｔｉ_５Ｓｉ_３の４相が存在していることが確認された。 In addition, as shown in FIGS. 5(e) and 5(f), in the case of an alloy to which neither Cr nor Al is added, in comparison sample 1 (65Mo-10Ti-5Si-10C-10B), before homogenization heat treatment, There are four phases of Mo _ss , T ₂ , (Ti, Mo) C, and (Mo, Ti) ₂ C, and in comparative sample 2 (55Mo-20Ti-5Si-10C-10B), Mo _ss , T ₂ , (Ti, Mo)C, and Ti ₅ Si ₃ were confirmed to exist.

１６００℃で１００時間の均質化熱処理を行うと、図６（ａ）および（ｂ）に示すように、Ｃｒを添加した試料２および５ともに、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃの３相となることが確認された。また、試料１、３、４、６についても、試料２および５と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃの３相となることが確認された。また、図６（ｃ）および（ｄ）に示すように、Ａｌを添加した試料７および９ともに、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）の４相となることが確認された。また、試料８、１０、１２についても、試料７および９と同様に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、Ｍｏ_３（Ａｌ、Ｓｉ）の４相となることが確認された。これは、Ａｌを添加すると、金属間化合物のＭｏ_３（Ａｌ、Ｓｉ）が生成しやすくなるためであると考えられる。また、試料１１については、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃの３相となることが確認された。 When _{homogenization} heat treatment was performed at 1600° C. for 100 _hours , as shown in FIGS. It was confirmed that there were three phases. It was also confirmed that samples 1, 3, 4 and 6, like samples 2 and 5, had three phases of Mo _ss , T ₂ and (Ti, Mo)C. Further, as shown in FIGS. 6(c) and (d), both Al-added samples 7 and 9 have four phases of Mo _ss , T ₂ , (Ti, Mo)C, and Mo ₃ (Al, Si). was confirmed to be It was also confirmed that Samples 8, 10, and 12, like Samples 7 and 9, had four phases of Mo _ss , T ₂ , (Ti, Mo)C, and Mo ₃ (Al, Si). This is probably because the addition of Al facilitates the formation of the intermetallic compound Mo ₃ (Al, Si). In addition, it was confirmed that sample 11 had three phases of Mo _ss , T ₂ and (Ti, Mo)C.

なお、図６（ｅ）および（ｆ）に示すように、比較試料１では、１８００℃で２４時間の均質化熱処理後も、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃ、（Ｍｏ、Ｔｉ）_２Ｃの４相のままであり、比較試料２では、１８００℃で２４時間の均質化熱処理後に、Ｍｏ_ｓｓ、Ｔ_２、（Ｔｉ、Ｍｏ）Ｃの３相となることが確認された。 Incidentally, as shown in FIGS. 6(e) and (f), in Comparative Sample 1, even after the homogenization heat treatment at 1800° C. for 24 hours, Mo _ss , T ₂ , (Ti, Mo)C, (Mo, Ti ) ₂ C, and in Comparative Sample 2, after the homogenization heat treatment at 1800° C. for 24 hours, it was confirmed to become three phases of Mo _ss , T ₂ and (Ti, Mo)C.

均質化熱処理後の試料１～３、５～１２および比較試料１について、ビッカース硬さ（Ｈｖ）の測定を行った。ビッカース硬さは、荷重を１ｋｇｆとして、１０点で測定を行い、その平均値を用いた。ビッカース硬さ（Ｈｖ）の測定結果を、図７（ａ）および（ｂ）に示す。図７（ａ）および（ｂ）に示すように、試料１～３、５～１２は、ビッカース硬さが比較試料１よりも大きく、１０００Ｈｖ以上であることが確認された。また、図７（ｂ）に示すように、Ａｌを含むＴｉ＋Ａｌ改質型の試料７～１２では、それぞれ試料７、９、１１よりもＡｌを多く含む試料８、１０、１２の方が、硬いことが確認された。 Vickers hardness (Hv) was measured for Samples 1 to 3, 5 to 12 and Comparative Sample 1 after the homogenization heat treatment. The Vickers hardness was measured at 10 points with a load of 1 kgf, and the average value was used. The measurement results of Vickers hardness (Hv) are shown in FIGS. 7(a) and 7(b). As shown in FIGS. 7(a) and 7(b), samples 1 to 3 and 5 to 12 were confirmed to have a Vickers hardness greater than that of comparative sample 1, being 1000 Hv or more. In addition, as shown in FIG. 7B, among Ti+Al modified samples 7 to 12 containing Al, samples 8, 10, and 12 containing more Al than samples 7, 9, and 11, respectively, are harder. was confirmed.

均質化熱処理後の試料１～１２および比較試料１について、密度の測定を行った。密度の測定結果を、図８（ａ）および（ｂ）に示す。図８（ａ）および（ｂ）に示すように、試料１～１２は、密度が比較試料１よりも小さく、軽量であることが確認された。また、Ｃｒを含むＴｉ＋Ｃｒ改質型の試料１～６では、Ｔｉ＋Ｃｒ濃度が高いほど、Ａｌを含むＴｉ＋Ａｌ改質型の試料７～１２では、Ｔｉ＋Ａｌ濃度が高いほど、密度が小さくなり軽くなることが確認された。なお、図８（ａ）および（ｂ）には、比較のため、Ｎｉ基単結晶超合金「ＴＭＳ－１３８」（A. Sato, A.-C. Yeh, T. Kobayashi, T. Yokokawa, H. Harada, T. Murakumom and J.X. Zhang, Energy Mater., 2 (2007) 19 - 25参照）の密度も示している。 Density measurements were performed on Samples 1 to 12 and Comparative Sample 1 after the homogenization heat treatment. The density measurement results are shown in FIGS. 8(a) and 8(b). As shown in FIGS. 8(a) and (b), it was confirmed that samples 1 to 12 had lower densities than comparative sample 1 and were lighter. In Ti + Cr modified type samples 1 to 6 containing Cr, the higher the Ti + Cr concentration, and in the Ti + Al modified type samples 7 to 12 containing Al, the higher the Ti + Al concentration, the lower the density and the lighter the weight. confirmed. For comparison, FIGS. 8(a) and 8(b) show the Ni-based single crystal superalloy “TMS-138” (A. Sato, A.-C. Yeh, T. Kobayashi, T. Yokokawa, H.). Harada, T. Murakumom and J.X. Zhang, Energy Mater., 2 (2007) 19-25) are also shown.

［Ｔｉを多く含み、Ｃｒを含むＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金について］
表１の試料４～６、１３および比較試料２について、均質化熱処理前の走査型電子顕微鏡（ＳＥＭ）による観察を行った。なお、これらの試料は全て、Ｔｉ濃度が２０原子％である。各試料のＳＥＭ写真を図９に示す。図９（ｃ）および（ｄ）に示すように、Ｃｒを多く含む試料５、６（40Mo-15Cr-20Ti-5Si-10C-10B、35Mo-20Cr-20Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、ＴｉＣ、Ｃｒ_３Ｓｉの４相が明瞭に認められるが、図９（ｂ）および（ａ）に示すように、Ｃｒの量が減少した試料４、１３（45Mo-10Cr-20Ti-5Si-10C-10B、50Mo-5Cr-20Ti-5Si-10C-10B）では、Ｃｒ_３Ｓｉの相が減少し、図５（ｆ）に示すように、Ｃｒを含まない比較試料２（55Mo-20Ti-5Si-10C-10B）では、Ｍｏ_ｓｓ、Ｔ_２、ＴｉＣ、Ｔｉ_５Ｓｉ_３の４相になっていることが確認された。 [Mo-Si-Ti-C-based alloy containing a large amount of Ti and containing Cr]
Samples 4 to 6, 13 and Comparative sample 2 in Table 1 were observed with a scanning electron microscope (SEM) before the homogenization heat treatment. All these samples have a Ti concentration of 20 atomic %. A SEM photograph of each sample is shown in FIG. As shown in FIGS. 9(c) and (d), in samples 5 and 6 (40Mo-15Cr-20Ti-5Si-10C-10B, 35Mo-20Cr-20Ti-5Si-10C-10B) containing a large amount of Cr, Mo Four phases of _ss , T ₂ , TiC, and Cr ₃ Si are clearly recognized, but as shown in FIGS. -5Si-10C-10B, 50Mo-5Cr-20Ti-5Si-10C-10B), the phase of _Cr3Si is reduced, and as shown in Fig. 5(f), comparative sample 2 (55Mo- _20Ti -5Si-10C-10B), four _phases of Moss, T2, TiC and _Ti5Si3 _were confirmed.

均質化熱処理前の試料４～６、１３および比較試料２について、酸化試験を行った。酸化試験では、各試料を、４×３×０．５ｍｍ^３の直方体に加工し、Ａｒ４０ｍｌ／ｍｉｎ－Ｏ_２１０ｍｌ／ｍｉｎ雰囲気中に、８００℃で８時間放置して酸化させた。熱重量分析（ＴＧＡ）により、酸化前後の各試料の質量の変化（Mass Change）Δｍを測定し、その結果を図１０（ａ）および（ｂ）に示す。また、酸化後の各試料の断面の顕微鏡観察結果を、図１１に示す。 Samples 4 to 6 and 13 before homogenization heat treatment and Comparative Sample 2 were subjected to an oxidation test. In the oxidation test, each sample was processed into a rectangular parallelepiped of 4×3×0.5 mm ³ and left in an atmosphere of Ar 40 ml/min—O ₂ 10 ml/min at 800° C. for 8 hours for oxidation. The mass change Δm of each sample before and after oxidation was measured by thermogravimetric analysis (TGA), and the results are shown in FIGS. 10(a) and 10(b). Further, FIG. 11 shows the result of microscopic observation of the cross section of each sample after oxidation.

図１０（ａ）に示すように、Ｃｒ濃度の上昇に従って、酸化による質量変化が小さくなることが確認された。すなわち、比較試料２、試料１３、試料４と、Ｃｒ濃度が大きくなるに従って、質量の減少割合が小さくなっており、さらにＣｒ濃度が大きい試料５および試料６の合金では、質量変化が小さく、耐酸化性に優れていることが確認された。その中でも、図１０（ｂ）に示すように、試料６の合金の質量変化が特に小さく、最も耐酸化性に優れていることが確認された。 As shown in FIG. 10(a), it was confirmed that the mass change due to oxidation decreased as the Cr concentration increased. That is, in comparative sample 2, sample 13, and sample 4, as the Cr concentration increases, the mass decrease rate decreases, and in the alloys of sample 5 and sample 6, which have high Cr concentrations, the mass change is small and the acid resistance is small. It was confirmed that the sintering property was excellent. Among them, as shown in FIG. 10(b), the mass change of the alloy of sample 6 was particularly small, and it was confirmed that the oxidation resistance was the best.

また、図１１（ａ）～（ｃ）に示すように、Ｃｒ濃度が小さくなるに従って、表面の酸化層が厚くなり、試料４の合金では酸化層の厚みが約１００μｍであり、試料１３の合金では、比較試料２と同程度に酸化層が広がっているのが確認された。また、図１１（ｄ）および（ｅ）に示すように、試料５および試料６の合金では、表面の薄い部分にのみ酸化層が存在していることが確認された。 Further, as shown in FIGS. 11A to 11C, as the Cr concentration decreases, the oxide layer on the surface becomes thicker. , it was confirmed that the oxide layer spreads to the same degree as in the comparative sample 2. Moreover, as shown in FIGS. 11(d) and 11(e), it was confirmed that the alloys of samples 5 and 6 had an oxide layer only in a thin portion of the surface.

同じＣｒ濃度の試料１と４、試料２と５、試料３と６の酸化試験結果（８００℃）を比較すると、図１０（ａ）に示す試料４、５、６の方が、それぞれ図２（ｂ）に示す試料１、２、３よりも、質量変化が小さくなっており、Ｔｉ＋Ｃｒ濃度が高いほど耐酸化性に優れることが確認された。 Comparing the oxidation test results (800° C.) of samples 1 and 4, samples 2 and 5, and samples 3 and 6 having the same Cr concentration, samples 4, 5, and 6 shown in FIG. The change in mass was smaller than that of samples 1, 2, and 3 shown in (b), and it was confirmed that the higher the Ti+Cr concentration, the better the oxidation resistance.

耐酸化性に優れた試料５および試料６について、酸化試験後の断面に対して、エネルギー分散型Ｘ線分光法（ＳＥＭ－ＥＤＸ）による元素分析を行い、その結果をそれぞれ図１２および図１３に示す。図１２（ｃ）および図１３（ｃ）に示すように、表面にのみ酸素が認められ、酸素が存在する酸化層の厚みは約１５μｍであることが確認された。 Regarding samples 5 and 6, which have excellent oxidation resistance, elemental analysis was performed on the cross section after the oxidation test by energy dispersive X-ray spectroscopy (SEM-EDX), and the results are shown in FIGS. 12 and 13, respectively. show. As shown in FIGS. 12(c) and 13(c), oxygen was observed only on the surface, and it was confirmed that the thickness of the oxide layer in which oxygen was present was about 15 μm.

試料４～６について、均質化熱処理後の走査型電子顕微鏡（ＳＥＭ）による観察を行った。各試料について、１６００℃で１０時間の均質化熱処理後のＳＥＭ写真を、図１４（ａ）～（ｃ）に、１６００℃で１００時間の均質化熱処理後のＳＥＭ写真を、図１４（ｄ）～（ｆ）に示す。図１４（ａ）～（ｆ）に示すように、熱処理時間の長短に関わらず、いずれの試料でも、Ｍｏ_ｓｓ、Ｔ_２、ＴｉＣの３相になっていることが確認された。 Samples 4 to 6 were observed with a scanning electron microscope (SEM) after the homogenization heat treatment. For each sample, SEM photographs after homogenization heat treatment at 1600° C. for 10 hours are shown in FIGS. 14(a) to (c), and SEM photographs after homogenization heat treatment at 1600° C. for 100 hours are shown in FIG. ~ (f). As shown in FIGS. 14(a) to 14(f), it was confirmed that three phases of Mo _ss , T ₂ and TiC were formed in all samples regardless of the length of the heat treatment time.

均質化熱処理後の試料５および試料６について、酸化試験を行った。酸化試験では、各試料を、４×３×０．５ｍｍ^３の直方体に加工し、Ａｒ４０ｍｌ／ｍｉｎ－Ｏ_２１０ｍｌ／ｍｉｎ雰囲気中に、所定温度で所定時間放置して酸化させた。熱重量分析（ＴＧＡ）により、酸化前後の各試料の質量の変化（Mass Change）Δｍを測定した。１６００℃で１００時間の均質化熱処理後の試料５および試料６について、７００℃、８００℃および９００℃で８時間放置して酸化させた結果を、図１５（ａ）に、８００℃で１００時間放置して酸化させた結果を、図１５（ｂ）に示す。また、１６００℃で１０時間、および、１６００℃で１００時間の均質化熱処理後の試料５および試料６について、８００℃で８時間放置して酸化させた結果を、図１５（ｃ）に示す。 An oxidation test was performed on Samples 5 and 6 after the homogenization heat treatment. In the oxidation test, each sample was processed into a rectangular parallelepiped of 4×3×0.5 mm ³ and left in an atmosphere of 40 ml/min of Ar—10 ml/min of O ₂ at a predetermined temperature for a predetermined period of time for oxidation. The mass change Δm of each sample before and after oxidation was measured by thermogravimetric analysis (TGA). Samples 5 and 6 after homogenization heat treatment at 1600°C for 100 hours were oxidized at 700°C, 800°C and 900°C for 8 hours. The results are shown in Fig. 15(a). The result of standing and oxidizing is shown in FIG.15(b). FIG. 15(c) shows the results of oxidizing Samples 5 and 6 after homogenization heat treatment at 1600° C. for 10 hours and 1600° C. for 100 hours, left at 800° C. for 8 hours.

図１５（ａ）に示すように、酸化時の温度が高くなるに従って、重量変化が大きくなっているのが確認された。また、図１５（ｂ）に示すように、酸化時間が長くなるほど、酸化が進むのが確認された。また、図１５（ｃ）に示すように、均質化熱処理の時間が長い方が、酸化しにくくなっており、耐酸化性に優れることが確認された。また、図１５（ａ）～（ｃ）に示すように、同じ酸化条件では、Ｃｒの量が多い試料６の合金の方が、試料５よりも重量変化が小さく、耐酸化性に優れていることが確認された。 As shown in FIG. 15(a), it was confirmed that the weight change increased as the temperature during oxidation increased. Moreover, as shown in FIG. 15(b), it was confirmed that the longer the oxidation time, the more the oxidation progressed. In addition, as shown in FIG. 15(c), it was confirmed that the longer the homogenization heat treatment time, the more difficult it was to oxidize, and the better the oxidation resistance. In addition, as shown in FIGS. 15A to 15C, under the same oxidation conditions, the alloy of sample 6, which has a large amount of Cr, has a smaller weight change than sample 5, and has excellent oxidation resistance. was confirmed.

均質化熱処理後の試料５および比較試料１、２について、各試料を２×２×４ｍｍ^３の直方体に加工し、１４００℃の真空中（＜１０^－３Ｐａ）で、ひずみ速度２．１×１０^－４ｓ^－１の条件で、高温圧縮試験を行った。なお、試料５は、１７００℃で２４時間の均質化熱処理、比較試料１および２は、１８００℃で２４時間の均質化熱処理を行っている。試験結果を、図１６に示す。図１６に示すように、Ｃｒを添加した試料５は、Ｃｒを添加していない比較試料１および２と比べて、高温強度（ピーク強度）が高くなっていることが確認された。 For sample 5 and comparative samples 1 and 2 after homogenization heat treatment, each sample was processed into a rectangular parallelepiped of 2 × 2 × 4 mm ³ and subjected to strain rate 2.1 × in vacuum (<10 ^-3 Pa) at 1400 ° C. A hot compression test was performed under the condition of 10 ^-4 s ^-1 . Note that sample 5 was subjected to homogenization heat treatment at 1700° C. for 24 hours, and comparative samples 1 and 2 were subjected to homogenization heat treatment at 1800° C. for 24 hours. The test results are shown in FIG. As shown in FIG. 16, it was confirmed that Sample 5 to which Cr was added had higher high-temperature strength (peak strength) than Comparative Samples 1 and 2 to which Cr was not added.

［ＴｉおよびＳｉを多く含み、Ｃｒを含むＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金について］
表１の試料１４、１５および比較試料３について、均質化熱処理前の走査型電子顕微鏡（ＳＥＭ）による観察を行った。なお、これらの試料は全て、Ｔｉ濃度が２８原子％、Ｓｉ濃度が１４原子％である。各試料のＳＥＭ写真を、図１７に示す。図１７（ａ）～（ｃ）に示すように、Ｃｒの量にかかわらず、試料１４、１５、比較試料３（40Mo-6Cr-28Ti-14Si-6C-6B、36Mo-10Cr-28Ti-14Si-6C-6B、46Mo-28Ti-14Si-6C-6B）ともに、Ｍｏ_ｓｓ、Ｔ_２［Ｍｏ_５ＳｉＢ_２］、ＴｉＣの３相に加えて、金属間化合物のＴｉ_５Ｓｉ_３が存在していることが確認された。 [Mo-Si-Ti-C-based alloy containing a large amount of Ti and Si and containing Cr]
Samples 14 and 15 and Comparative Sample 3 in Table 1 were observed with a scanning electron microscope (SEM) before the homogenization heat treatment. All of these samples have a Ti concentration of 28 atomic % and a Si concentration of 14 atomic %. A SEM photograph of each sample is shown in FIG. As shown in FIGS. 17(a) to (c), samples 14 and 15 and comparative sample 3 (40Mo-6Cr-28Ti-14Si-6C-6B, 36Mo-10Cr-28Ti-14Si- 6C-6B, 46Mo-28Ti-14Si-6C-6B), in addition to the three phases of Mo _ss , T ₂ [Mo ₅ SiB ₂ ], and TiC, an intermetallic compound Ti ₅ Si ₃ is present. was confirmed.

試料１４、１５および比較試料３について、１６００℃で２４時間の均質化熱処理後の走査型電子顕微鏡（ＳＥＭ）による観察を行った。各試料のＳＥＭ写真を、図１８に示す。図１８（ａ）～（ｃ）に示すように、いずれの試料でも、熱処理前と同じく、Ｍｏ_ｓｓ、Ｔ_２［Ｍｏ_５ＳｉＢ_２］、ＴｉＣ、Ｔｉ_５Ｓｉ_３の４相が存在していることが確認された。 Samples 14, 15 and Comparative Sample 3 were observed by scanning electron microscopy (SEM) after homogenization heat treatment at 1600° C. for 24 hours. A SEM photograph of each sample is shown in FIG. As shown in FIGS. 18(a) to 18(c), in all samples, the same four phases of Mo _ss , T ₂ [Mo ₅ SiB ₂ ], TiC, and Ti ₅ Si ₃ exist as before the heat treatment. was confirmed.

均質化熱処理後の試料１４、１５および比較試料１、３について、密度の測定を行った。密度の測定結果を、図１９に示す。なお、比較試料１は、１８００℃で２４時間の均質化熱処理を行ったものである。図１９に示すように、試料１４、１５および比較試料３は、密度が比較試料１よりも顕著に小さく、軽量であることが確認された。また、比較試料３、試料１４、試料１５の順で密度が小さくなっており、Ｃｒを多く含むほど密度が小さくなり、軽くなることが確認された。 Density measurements were performed on Samples 14 and 15 and Comparative Samples 1 and 3 after the homogenization heat treatment. The density measurement results are shown in FIG. Comparative sample 1 was subjected to homogenization heat treatment at 1800° C. for 24 hours. As shown in FIG. 19, it was confirmed that Samples 14 and 15 and Comparative Sample 3 had significantly lower densities than Comparative Sample 1 and were lighter. Also, the density decreases in the order of Comparative Sample 3, Sample 14, and Sample 15, and it was confirmed that the more Cr included, the lower the density and the lighter the weight.

均質化熱処理後の試料１４、１５および比較試料１、３について、酸化試験を行った。酸化試験では、各試料を、４×３×０．５ｍｍ^３の直方体に加工し、Ａｒ４０ｍｌ／ｍｉｎ－Ｏ_２１０ｍｌ／ｍｉｎ雰囲気中に、所定温度で所定時間放置して酸化させた。熱重量分析（ＴＧＡ）により、酸化前後の各試料の質量の変化（Mass Change）Δｍを測定した。各試料について、８００℃で２４時間まで放置して酸化させた結果を、図２０（ａ）に、１１００℃で２４時間まで放置して酸化させた結果を、図２０（ｂ）に示す。 An oxidation test was performed on samples 14 and 15 and comparative samples 1 and 3 after the homogenization heat treatment. In the oxidation test, each sample was processed into a rectangular parallelepiped of 4×3×0.5 mm ³ and left in an atmosphere of 40 ml/min of Ar—10 ml/min of O ₂ at a predetermined temperature for a predetermined period of time for oxidation. The mass change Δm of each sample before and after oxidation was measured by thermogravimetric analysis (TGA). FIG. 20(a) shows the results of oxidizing each sample at 800° C. for 24 hours, and FIG. 20(b) shows the results of oxidizing at 1100° C. for 24 hours.

図２０に示すように、８００℃および１１００℃の場合ともに、Ｃｒ濃度の上昇に伴って、酸化による質量変化が小さくなることが確認された。すなわち、図２０に示すように、比較試料３の合金では、比較試料１ほどではないが、時間と共に質量が大きく減少しており、酸化されやすいのに対し、Ｃｒを含む試料１４、１５の合金では質量変化が小さく、耐酸化性に優れていることが確認された。特に、試料１５の方が試料１４よりも質量変化が小さくなっており、Ｃｒを多く含むほど耐酸化性に優れていることが確認された。 As shown in FIG. 20, both at 800° C. and 1100° C., it was confirmed that the mass change due to oxidation decreased as the Cr concentration increased. That is, as shown in FIG. 20, in the alloy of Comparative Sample 3, the mass decreased significantly with time, although not as much as in Comparative Sample 1, and was easily oxidized, whereas the alloys of Samples 14 and 15 containing Cr were easily oxidized. It was confirmed that the mass change was small and the oxidation resistance was excellent. In particular, sample 15 had a smaller mass change than sample 14, and it was confirmed that the more Cr included, the more excellent the oxidation resistance.

Ｃｒ濃度が同じ１０原子％の試料１、４、１５を比較すると、密度では、図８（ａ）に示す試料１、４よりも、図１９に示す試料１５の方が小さくなっており、Ｔｉ＋Ｓｉ＋Ｃｒ濃度が高いほど密度が小さくなり、軽くなることが確認された。また、酸化試験では、８００℃の場合、図２（ｂ）に示す試料１、図１０（ａ）に示す試料４、図２０（ａ）に示す試料１５の順で、質量変化が小さくなっており、Ｔｉ＋Ｓｉ＋Ｃｒ濃度が高いほど耐酸化性に優れることが確認された。 When samples 1, 4, and 15 having the same Cr concentration of 10 atomic % are compared, the density of sample 15 shown in FIG. 19 is lower than that of samples 1 and 4 shown in FIG. It was confirmed that the higher the concentration, the smaller the density and the lighter the weight. In the oxidation test, at 800° C., the change in mass decreased in the order of sample 1 shown in FIG. 2(b), sample 4 shown in FIG. 10(a), and sample 15 shown in FIG. It was confirmed that the higher the Ti+Si+Cr concentration, the better the oxidation resistance.

［ＴｉおよびＳｉを多く含み、ＣｒおよびＡｌを含むＭｏ－Ｓｉ－Ｔｉ－Ｃ系合金について］
表１の試料１６について、均質化熱処理前の走査型電子顕微鏡（ＳＥＭ）による観察を行った。そのＳＥＭ写真を、図２１に示す。図２１に示すように、試料１６（30Mo-40Ti-15Si-5Cr-5Al-5C）では、Ｍｏ_ｓｓ、ＴｉＣの２相に加えて、金属間化合物のＴｉ_５Ｓｉ_３が存在していることが確認された。また、試料１６について、１６００℃で２４時間の均質化熱処理を行ったもの、および、１６００℃で１００時間の均質化熱処理を行ったものについて、走査型電子顕微鏡により観察を行ったところ、均質化熱処理前と同じ、Ｍｏ_ｓｓ、ＴｉＣ、Ｔｉ_５Ｓｉ_３の３相が存在していることが確認された。 [Mo-Si-Ti-C-based alloy containing a large amount of Ti and Si and containing Cr and Al]
Sample 16 in Table 1 was observed with a scanning electron microscope (SEM) before the homogenization heat treatment. Its SEM photograph is shown in FIG. As shown in FIG. 21, in sample 16 (30Mo-40Ti-15Si-5Cr- _5Al _- 5C), in addition to the two phases of Moss and TiC, it was found that an intermetallic compound _Ti5Si3 was present. confirmed. In addition, when sample 16 was subjected to homogenization heat treatment at 1600 ° C. for 24 hours and that was subjected to homogenization heat treatment at 1600 ° C. for 100 hours, observation with a scanning electron microscope revealed that homogenization It was confirmed that the same three phases of Mo _ss , TiC, and Ti ₅ Si ₃ as before the heat treatment were present.

試料１６について、１６００℃で２４時間の均質化熱処理を行ったものについて、密度を測定したところ、６．２７４ｇ／ｃｍ^３であった。試料１６は、図８（ａ）および（ｂ）や、図１９に示す各試料の密度と比較しても、密度が顕著に小さく、軽量であることが確認された。これは、Ｔｉを多く含んでいることや、ＣｒおよびＡｌを含んでいることによるものと考えられる。 The density of sample 16, which was subjected to homogenization heat treatment at 1600° C. for 24 hours, was 6.274 g/cm ³ . It was confirmed that the density of sample 16 was remarkably smaller and lighter than the densities of the samples shown in FIGS. 8(a) and (b) and FIG. This is considered to be due to the large amount of Ti and the inclusion of Cr and Al.

均質化熱処理前の試料１６について、酸化試験を行った。酸化試験では、各試料を、４×３×０．５ｍｍ^３の直方体に加工し、Ａｒ４０ｍｌ／ｍｉｎ－Ｏ_２１０ｍｌ／ｍｉｎ雰囲気中に、７００℃、９００℃、１１００℃で所定時間放置して酸化させた。熱重量分析（ＴＧＡ）により、酸化前後の試料１６の重量の変化（Weight Change）Δｗを測定した。各温度で２４時間まで放置して酸化させた結果を、図２２に示す。なお、比較のため、表１に示す比較試料４（38Mo-17Si-5B-20Ti-10TiC）についても、同様の方法で、１１００℃での酸化試験を行い、その結果を図２２中に示す。 An oxidation test was performed on Sample 16 before the homogenization heat treatment. In the oxidation test, each sample was processed into a rectangular parallelepiped of 4×3×0.5 mm ³ and left in an atmosphere of 40 ml/min of Ar—10 ml/min of O ₂ at 700° C., 900° C., and 1100° C. for a predetermined time to oxidize. let me The weight change Δw of sample 16 before and after oxidation was measured by thermogravimetric analysis (TGA). FIG. 22 shows the results of oxidizing by standing at each temperature for up to 24 hours. For comparison, comparative sample 4 (38Mo-17Si-5B-20Ti-10TiC) shown in Table 1 was also subjected to an oxidation test at 1100° C. in the same manner, and the results are shown in FIG.

図２２に示すように、７００℃および９００℃の場合に、酸化による質量変化がほとんど認められないことが確認された。また、１１００℃の場合には、酸化による質量の減少が若干認められたが、比較試料４と比べると、非常に小さい変化であることが確認された。このように、試料１６は、高温での耐酸化性に非常に優れていることが確認された。
As shown in FIG. 22, it was confirmed that almost no change in mass due to oxidation was observed at 700° C. and 900° C. Also, in the case of 1100° C., a slight decrease in mass due to oxidation was observed, but compared with Comparative Sample 4, it was confirmed that the change was very small. Thus, it was confirmed that sample 16 was extremely excellent in oxidation resistance at high temperatures.

Claims

Mo, Si, Ti, C, and Crand/or Al,
28 atomic % or more and 60 atomic % or less of Mo, 1.7 atomic % or more and 20.0 atomic % or less of Si, 5.0 atomic % or more and 42.0 atomic % or less of Ti, and 4.0 atomic % of C atomic % or more and 15.0 atomic % or less, and the combined Cr and Al content is 2.0 atomic % or more and 25.0 atomic % or less That
A Mo-Si-Ti-C alloy characterized by:

consisting of Mo, Si, Ti, C, Cr and/or Al, and B;
28 atomic % or more and 60 atomic % or less of Mo, 1.7 atomic % or more and 20.0 atomic % or less of Si, 5.0 atomic % or more and 42.0 atomic % or less of Ti, and 4.0 atomic % of C atomic % or more and 15.0 atomic % or less, said Cr and said Al together is 2.0 atomic % or more and 25.0 atomic % or less, and said B is 3.3 atomic % or more and 13.3 atomic % or less. to be
A Mo-Si-Ti-C alloy characterized by:

3. The Mo--Si--Ti--C alloy according to claim 1 , wherein said Cr and said Al together are 5.5 atomic % or more and 25.0 atomic % or less.

The Si content is 1.7 atomic % or more and 6.7 atomic % or less, the Ti content is 5.0 atomic % or more and 25.0 atomic % or less, and the Cr content is 12.0 atomic % or more and 23.0 atomic % or less. The Mo-Si-Ti-C alloy according to claim 1 or 2 , characterized by:

The Si content is 1.7 atomic % or more and 6.7 atomic % or less, the Ti content is 12.0 atomic % or more and 30.0 atomic % or less, and the Al content is 2.0 atomic % or more and 7.0 atomic % or less. The Mo-Si-Ti-C alloy according to claim 1 or 2 , characterized by:

The Si content is 10.0 atomic % or more and 20.0 atomic % or less, the Ti content is 23.0 atomic % or more and 42.0 atomic % or less, and the Cr content is 4.5 atomic % or more and 13.0 atomic % or less. The Mo-Si-Ti-C alloy according to claim 1 or 2 , characterized by:

It consists of Mo, Si, Ti, C, Cr and/or Al, the Mo content is 28 atomic percent or more and 60 atomic percent or less, the Si content is 1.7 atomic percent or more and 20.0 atomic percent or less, and the 5.0 atomic % or more and 42.0 atomic % or less of Ti, 4.0 atomic % or more and 15.0 atomic % or less of C, and 2.0 atomic % or more and 25.0 atomic % of Cr and Al together A method for producing a Mo--Si--Ti--C alloy, characterized by melting and casting a raw material containing 10% or less .

Consisting of Mo, Si, Ti, C, Cr and/or Al, and B, wherein Mo is 28 atomic % or more and 60 atomic % or less, and Si is 1.7 atomic % or more and 20.0 atomic % Below, the Ti content is 5.0 atomic percent or more and 42.0 atomic percent or less, the C content is 4.0 atomic percent or more and 15.0 atomic percent or less, and the Cr and Al combined are 2.0 atomic percent or more and 25 atomic percent. A method for producing a Mo--Si--Ti--C alloy, characterized by melting and casting a raw material containing 0 atomic % or less and 3.3 atomic % or more and 13.3 atomic % or less of said B. .

9. The method for producing a Mo--Si--Ti--C alloy according to claim 7 , wherein a homogenization heat treatment is performed at 1500.degree. C. to 1900.degree. C. for 1 hour to 120 hours after casting.