JP4074491B2 - Zinc-based alloy and method for producing the same - Google Patents

Description

【００２４】
さらに、乾燥された各試験材４０に対し、窒素ガスを流しながら、３５０℃で６０分間の熱処理が施された。この熱処理後に、各試験材４０を中央断面で切断し、反応部厚さを金属顕微鏡で確認するとともに、表面硬度（Ｈｖ）および最表面から内部に５ｍｍの位置の合金部硬度（Ｈｖ）を測定した。その結果が、表１に示されている。
【００２５】
一方、別に用意された各試験材４０と粉末塗布を行わないＺＡＳ材とに対し、アルミニウム溶湯による浸食試験が施された。具体的には、７００℃程度に加熱されているアルミニウム溶湯（ＡＤＣ１２相当）に、各試験材４０を３０分間、６０分間および９０分間ずつ浸漬した。その後、試験材４０をアルミニウム溶湯から取り出して中央断面で切断するとともに、形状変化を確認して浸食状況を検出した。
【００２６】
図４には、代表的な浸食状況が示されている。これにより、ＺＡＳ材のみの場合、溶損が大きくなって元の形状を維持することができなかった。これに対して、粉末Ａ〜Ｆが塗布された実施例１では、耐食性の大幅な向上が確認された。
【００２７】
その際、Ｃｕ（粉末Ａ）、Ｃｕ−Ｎｉ（粉末Ｂ）、Ｃｕ−Ｎｉ−Ｃｒ（粉末Ｃ）、Ｃｕ−Ｎｉ−Ｃｒ−Ｍｏ（粉末Ｄ）、Ｃｕ−Ｎｉ−Ｆｅ−Ｃｒ−Ｍｏ（粉末Ｅ）およびＣｕ−Ｎｉ−Ｆｅ−Ｃｏ−セラミックス（粉末Ｆ）の順に、溶損が減少した。さらに、浸漬時間に対して溶損が減少し、その溶損速度が大きく減少する傾向があった。
【００２８】
［参考例］
図５に示す金型５０は、通常、ＺＡＳ合金で構成されている。この種の金型５０では、数千ショットでクラックの発生が認められた。例えば、コーナー部では、１０００ショットでクラックが入り始めており、各金型合わせ面では、２０００ショット〜４０００ショットでクラックが入り始めていた。そして、ショット数が増加するのに伴って、クラックが拡大した。
【００２９】
そこで、実施例１の粉末Ａを使用して、金型５０の表面処理を施した。処理条件としては、粉末の塗布厚さが１．５ｍｍであり、窒素ガスを流しながら、５００℃で３０分間の熱処理が施された。次に、仕上げ加工を行った後、表面硬度を検出したところ、その表面硬度がＨｖ２００程度であり、硬化層の深さが５ｍｍであった。
【００３０】
さらに、金型５０にクラックが入り始めるショット数は、コーナー部で１０００ショットから１８０００ショットに増加するとともに、各金型合わせ面で、２０００ショットから３５０００ショットに、３０００ショットから４５０００ショットに、４０００ショットから８００００ショットにそれぞれ大幅に増加した。
【００３１】
これにより、従来の鋼材型に比べ型として構成し易く、しかも軽量で取り扱い利便性に優れる亜鉛基合金型を使用して、鋼材型と同等の耐久性を得ることが可能になった。
【００３２】
【発明の効果】
本発明に係る亜鉛基合金では、亜鉛または亜鉛合金の表層に真鍮拡散層が設けられるため、実際に使用される表面の融点、強度および耐熱性が母材金属に比べて相当に高くなり、耐摩耗性、耐熱性および耐衝撃性等の物性の向上が確実に図られる。
【００３３】
また、本発明に係る亜鉛基合金の製造方法では、亜鉛基合金の母材金属を所定の形状に加工した後、前記母材金属の少なくとも一部に、銅およびマンガンを必須成分とし、かつ鉄、ニッケル、クロム、モリブデン、コバルトまたはセラミックスの少なくとも１種を含有する粉末が塗布される。次いで、粉末が塗布された母材金属の部位が、不活性雰囲気下で加熱される。このため、表層に母層より硬度、強度および耐食性に優れた合金層が確実に得られ、金型等の種々の部品に良好に使用することが可能になる。
【図面の簡単な説明】
【図１】 本発明の実施形態に係る亜鉛基合金で構成された金型の断面概略説明図である。
【図２】 前記金型の製造方法を説明する工程図である。
【図３】 実施例１に使用される試験材の説明図である。
【図４】 前記試験材のアルミニウム溶湯による浸食試験の説明図である。
【図５】 実施例２に使用される型の斜視説明図である。
【符号の説明】
１０、５０…金型 １２…母材
１４…合金層 ２２…加工面
２４…塗布機 ２６…粉末
３０…加熱装置 ４０…試験材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a zinc-based alloy in which an alloy layer harder than a mother layer is formed on a surface layer and a method for producing the same.
[0002]
[Prior art]
Usually, zinc-based alloys such as ZAS alloys ( Zn-Al- Cu-Mg- based alloys ) have a low melting point, a slow oxidation process, and a low strength and hardness compared to aluminum. Yes. For this reason, zinc-based alloys are used as casting materials, and in addition to prototype molds, complicated shaped keys, key cylinders, and the like are manufactured.
[0003]
However, since the strength and hardness of zinc-based alloys are low, the durability of cast products such as molds and keys is low, which is uneconomical. In order to cure the surface of the zinc-based alloy, for example, a manufacturing method disclosed in Japanese Patent No. 2832224 is known.
[0004]
In this prior art, when performing electroless nickel plating directly on the surface of a mold made of a zinc-based alloy, the mold is immersed in an electroless nickel plating solution containing an organic acid nickel salt or the like. As a result, since the nickel coating is directly applied to the zinc-based alloy, the film peeling does not occur, and since it is dense and does not generate cracks, the wear resistance and the corrosion resistance are improved.
[0005]
[Problems to be solved by the invention]
However, in the above prior art, only a plating layer is provided on the surface of the zinc-based alloy, and the hardened layer (plating layer) is limited only to the surface layer portion. Thereby, there exists a problem that sufficient intensity | strength and heat resistance cannot be provided to a zinc base alloy.
[0006]
The present invention solves this type of problem, and provides a zinc-based alloy that is excellent in workability and can reliably impart desired strength and heat resistance to a surface layer portion, and a method for producing the same. Objective.
[0007]
[Means for Solving the Problems]
In the zinc-based alloy according to the present invention, an alloy layer that is harder than the base layer is formed on the surface layer, and this alloy layer is made of iron, nickel, chromium, molybdenum, cobalt, and a base metal made of zinc-based alloy. at least one preparative, and copper and manganese constitute a brass diffusion layer formed by diffusing from the outside. For this reason, the melting point, strength and heat resistance of the actually used surface are considerably higher than that of zinc or zinc alloy as the base metal, and physical properties such as wear resistance, heat resistance and impact resistance are improved. Certainly planned. Therefore, it can be used well for various parts.
[0008]
Moreover, since the base metal is zinc or a zinc alloy, it has a low melting point and can be easily molded by casting, and has excellent workability. Thereby, it is satisfactorily used as a mold material for casting or resin molding having a complicated shape.
[0009]
In the method for producing a zinc-based alloy according to the present invention, after processing the base metal of the zinc-base alloy into a predetermined shape, copper and manganese are essential components in at least a part of the base metal, and iron , nickel, chromium, molybdenum, a powder containing at least one cobalt is applied. Next, the base metal portion coated with the powder is heated under an inert atmosphere.
[0010]
Thus, nickel is added to improve strength, hardness and corrosion resistance over the base metal, while iron, chromium, molybdenum or cobalt functions as an element to improve hardness, strength and corrosion resistance. Furthermore, by adding ceramics, it is possible to improve the strength and hardness and improve the wear resistance. For this reason, an alloy layer (brass diffusion layer) superior in hardness, strength, corrosion resistance, and the like is reliably obtained on the surface layer than the base layer, and can be used favorably for various parts such as molds.
[0011]
The zinc-based alloy will be described in more detail. Since the base metal is mainly zinc (Zn), the surface and the vicinity of the surface can be brassed. Brass is an alloy of copper (Cu) and zinc, and has a melting point, strength and hardness more than twice that of zinc, and also has high corrosion resistance. Since the copper component moves to the base material phase, a brass diffusion layer having a diffusion region width of about 10 mm is formed.
[0012]
Furthermore, copper is a binder of iron (Fe), nickel (Ni), chromium (Cr), molybdenum (Mo), cobalt (Co) or ceramic powder metallurgy. For this reason, the outermost layer of the zinc-based alloy can be composed of an alloy layer containing at least one of iron, nickel, chromium, molybdenum, cobalt, or ceramics, and a surface layer having high corrosion resistance and wear resistance can be provided. become.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic sectional view of a mold 10 made of a zinc-based alloy according to an embodiment of the present invention.
[0014]
The mold 10 is provided with a base material 12 constituting a base layer, and an alloy layer 14 harder than the base material 12 is formed on the surface layer. This alloy layer 14 constitutes a brass diffusion layer containing at least one of iron (Fe), nickel (Ni), chromium (Cr), molybdenum (Mo), cobalt (Co), or ceramics. The base material 12 is made of zinc or a zinc alloy, and specifically, Zn, Zn—Al, Zn—Sn, or a ZAS alloy is used.
[0015]
A method of manufacturing the mold 10 configured as described above will be described below with reference to a process chart shown in FIG.
[0016]
First, a base material 12 made of zinc or a zinc alloy is prepared, and the base material 12 is processed by a processing machine 20 so that the base material 12 has a processed surface corresponding to a cavity. 22 is formed.
[0017]
Next, the powder 26 is applied to the processed surface 22 via the coating machine 24. The powder 26 contains copper and manganese as essential components, and contains at least one of iron, nickel, chromium, molybdenum, cobalt, and ceramics. The powder 26 is dispersed in an organic solvent and paste-like with respect to the processed surface 22. Applied.
[0018]
The base material 12 to which the powder 26 has been applied is placed in the heating device 30 after being dried. The heating device 30 includes a heating source 32 such as a burner or a heater, and the base material 12 is heat-treated in the heating device 30 in an inert atmosphere, for example, a nitrogen gas (N ₂ gas) atmosphere. Thereby, the metal mold | die 10 by which the alloy layer 14 harder than the base material 12 was provided in the surface layer is obtained. The mold 10 is subjected to a finishing process such as a surface polishing process.
[0019]
In this case, in this embodiment, the alloy layer 14 is provided on the surface of the base material 12, and the alloy layer 14 is a brass diffusion layer containing at least one of iron, nickel, chromium, molybdenum, cobalt, or ceramics. It is composed. For this reason, the melting point, strength and heat resistance of the surface actually used are considerably higher than that of the base material 12 such as zinc or zinc alloy, and physical properties such as wear resistance, heat resistance and impact resistance are improved. Certainly planned. Therefore, the effect that it can be used favorably for various parts is obtained.
[0020]
Moreover, since the base material 12 is zinc or a zinc alloy, it has a low melting point and can be easily molded by casting, and has excellent workability. Thereby, it is satisfactorily used as a mold material for casting or resin molding having a complicated shape.
[0021]
【Example】
[Example 1]
A base material 12 made of a Zn—Al— Cu—Mg alloy (hereinafter also referred to as a ZAS material), which is frequently used as a zinc alloy in a simple type or a test type, was prepared. Using this base material 12, a stepped rod-shaped test material 40 was formed as shown in FIG.
[0022]
Next, powders A, B, C, D, E, and F having the composition (wt%) shown in Table 1 were prepared, and a dispersant was added to these using xylene as a solvent, which was formed into a paste from the slurry. These paste-like powders A, B, C, D, E and F were each applied to the surface of the test material 40 to a thickness of about 0.3 mm, and then dried.
[0023]
[Table 1]

[0024]
Further, each dried test material 40 was subjected to heat treatment at 350 ° C. for 60 minutes while flowing nitrogen gas. After this heat treatment, each test material 40 was cut at the central cross section, the thickness of the reaction part was confirmed with a metal microscope, and the surface hardness (Hv) and the alloy part hardness (Hv) at a position of 5 mm from the outermost surface were measured. did. The results are shown in Table 1.
[0025]
On the other hand, an erosion test with molten aluminum was performed on each separately prepared test material 40 and a ZAS material on which powder application was not performed. Specifically, each test material 40 was immersed in molten aluminum (equivalent to ADC12) heated to about 700 ° C. for 30 minutes, 60 minutes, and 90 minutes. Thereafter, the test material 40 was taken out from the molten aluminum and cut at the central cross section, and the erosion status was detected by confirming the shape change.
[0026]
FIG. 4 shows a typical erosion situation. As a result, in the case of only the ZAS material, the melting loss increased and the original shape could not be maintained. On the other hand, in Example 1 to which powders A to F were applied, a significant improvement in corrosion resistance was confirmed.
[0027]
At that time, Cu (powder A), Cu-Ni (powder B), Cu-Ni-Cr (powder C), Cu-Ni-Cr-Mo (powder D), Cu-Ni-Fe-Cr-Mo (powder) The erosion loss decreased in the order of E) and Cu-Ni-Fe-Co-ceramics (powder F). Furthermore, the melting loss decreased with respect to the immersion time, and the melting rate thereof tended to decrease greatly.
[0028]
[ Reference example ]
The mold 50 shown in FIG. 5 is usually made of a ZAS alloy. In this type of mold 50, cracks were observed after several thousand shots. For example, cracks began to occur at 1000 shots at the corner, and cracks began to occur at 2000 to 4000 shots at each die mating surface. As the number of shots increased, the cracks expanded.
[0029]
Therefore, the surface treatment of the mold 50 was performed using the powder A of Example 1. As processing conditions, the coating thickness of the powder was 1.5 mm, and heat treatment was performed at 500 ° C. for 30 minutes while flowing nitrogen gas. Next, after finishing, the surface hardness was detected. The surface hardness was about Hv200, and the depth of the hardened layer was 5 mm.
[0030]
Furthermore, the number of shots at which cracks begin to enter the mold 50 increases from 1000 shots to 18000 shots at the corners, and from 2000 shots to 35000 shots, from 3000 shots to 45000 shots, and 4000 shots at each mold mating surface. From 8 to 80000 shots.
[0031]
This makes it possible to obtain durability equivalent to that of a steel material mold by using a zinc-based alloy mold that is easier to configure as a mold than a conventional steel material mold and that is light in weight and excellent in handling convenience.
[0032]
【The invention's effect】
In the zinc-based alloy according to the present invention, since the brass diffusion layer is provided on the surface layer of zinc or zinc alloy, the melting point, strength and heat resistance of the surface actually used are considerably higher than those of the base metal, and resistance to Improvements in physical properties such as wear, heat resistance and impact resistance are ensured.
[0033]
In the method for producing a zinc-based alloy according to the present invention, after processing the base metal of the zinc-base alloy into a predetermined shape, copper and manganese are essential components in at least a part of the base metal, and iron A powder containing at least one of nickel, chromium, molybdenum, cobalt or ceramics is applied. Next, the base metal portion coated with the powder is heated under an inert atmosphere. For this reason, an alloy layer having higher hardness, strength, and corrosion resistance than that of the mother layer is reliably obtained on the surface layer, and can be used favorably for various parts such as molds.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional explanatory view of a mold made of a zinc-based alloy according to an embodiment of the present invention.
FIG. 2 is a process diagram illustrating a method for manufacturing the mold.
3 is an explanatory diagram of a test material used in Example 1. FIG.
FIG. 4 is an explanatory diagram of an erosion test with a molten aluminum of the test material.
5 is a perspective explanatory view of a mold used in Example 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10, 50 ... Mold 12 ... Base material 14 ... Alloy layer 22 ... Work surface 24 ... Coating machine 26 ... Powder 30 ... Heating device 40 ... Test material

Claims (2)

A zinc-based alloy in which an alloy layer harder than the mother layer is formed on the surface layer,
The alloy layer is to base metal consisting of zinc based alloy, iron, nickel, chromium, molybdenum, and at least one cobalt, copper and brass diffusion layer and manganese are formed by diffusion from the outside A zinc-based alloy characterized by being. A method for producing a zinc-based alloy in which an alloy layer harder than a mother layer is formed on a surface layer,
Processing the base metal of the zinc-based alloy into a predetermined shape;
Applying a powder containing copper and manganese as essential components and containing at least one of iron, nickel, chromium, molybdenum, and cobalt to at least a part of the base metal;
Heating the base metal part coated with the powder in an inert atmosphere;
A method for producing a zinc-base alloy, comprising:

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