JPH0753904B2 - Liquid phase diffusion bonding method for γ'reinforced Ni-based heat resistant alloy members - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid phase diffusion bonding method for a γ ′ reinforced Ni-base heat-resistant alloy member capable of forming a joint having high creep strength.

[Conventional technology]

Generally, for members requiring high-temperature strength, for example, jet engine members, C: 0.02 to 0.15%, Cr: 6 to 25%, Ti: 0.2 to 5% by weight (hereinafter% indicates% by weight). %, Al: 0.2 to 6.5%, and Si: 0.01 to 0.85%, Mn: 0.01 to 0.85%, Co: 1 to 30%, Mo: 1 to 10%, Fe: 0.15 to 25%, B: 0.005 to 1.2%, W: 0.1 to 10%, Nb: 0.1 to 5%, one or more of, and the balance consisting of Ni and inevitable impurities, and γ in the matrix. ′, That is, γ ′ reinforced Ni-base heat-resistant alloy having a structure in which Ni ₃ (Al, Ti) is finely and uniformly dispersed and precipitated, and these γ′-reinforced Ni-base heat-resistant alloy members are
Ni-Cr-B alloy foil material or powder is used as the brazing material, and the brazing material is sandwiched between the joint surfaces of the members, and the liquid phase at a temperature of 1075 to 1200 ° C in a vacuum or an inert gas atmosphere. Diffusion bonding is well known.

[Problems to be solved by the invention]

However, in the γ'reinforced Ni-based heat-resistant alloy members brazed by the above-mentioned conventional liquid phase diffusion bonding method, the creep strength of the bonded portion is not sufficiently satisfied, and therefore the bonding of these members It is strongly desired to improve the creep strength in the part.

[Means for solving problems]

Therefore, the present inventors have conducted research to improve the creep strength at the joint portion of the γ'reinforced Ni-based heat-resistant alloy member brazed by liquid phase diffusion bonding from the above viewpoint, and as a result, conventional In the liquid phase diffusion bonding method, if the brazing material is a foil material, the thickness is extremely thin at 20 to 50 μm,
In the state where the brazing filler metal is set, depending on the shape of the joint surface, a minute space may be formed in the joint due to slackening or cutting of the brazing filler metal. Since it is not possible to evenly distribute it in the extremely thin state on the joint surface of, the liquid-phase diffusion reaction during brazing becomes locally uneven, and this is the reason why it is sufficiently satisfied. It has been found that it is not possible to form a joint having creep strength capable of producing an ion plating device or a sputtering device before the brazing of the joint surface of a γ'reinforced Ni-based heat-resistant alloy member. In the above, in a state of being cleaned by ion bombardment, a brazing material layer of a Ni-Cr-B alloy is vapor-deposited on one or both of them, and the brazing material layer before the joining surface of the members is Brazing material is completely in close contact,
Moreover, since this brazing filler metal layer has a uniform thickness, even if the brazing filler metal layer is thin, the liquid phase diffusion during brazing will be carried out uniformly over the entire joint surface. The creep strength increases remarkably, and when a metal film of Pd, Pt, Cr, or a Cr-Ni alloy is vapor-deposited as a surface layer on the same ion plating device or spattering device, this metal film is formed. Since it is extremely difficult to oxidize, it is possible to have time before brazing, and the oxygen supply area is smaller than when using foil or powdered brazing filler metal, which is useful for improving brazing workability. I got it.

The present invention has been made on the basis of the above-mentioned findings. Prior to brazing when liquid-phase diffusion bonding of a γ'reinforced Ni-based heat-resistant alloy member using a Ni-Cr-B alloy brazing material, In an ion plating apparatus or a sputtering apparatus, after the joint surface of the member is cleaned by ion bombardment, the brazing material layer of the Ni-Cr-B alloy is vapor-deposited on one or both of the cleaning joint surfaces. To form a joint having high creep strength, and if necessary, with the same ion plating device or cleaning device, followed by a metal film of Pd, Pt, Cr, or Cr-Ni alloy. Liquid phase diffusion welding of γ'reinforced Ni-based heat-resistant alloy members, which was designed to give oxidation resistance to the joint surface before brazing. Those having features a method.

〔Example〕

Next, the method of the present invention will be specifically described by way of Examples.

First, as a γ'reinforced Ni-based heat-resistant alloy member, all had dimensions of diameter: 15 mmφ x length: 60 mm, and each had the first
Prepare a test piece having the composition shown in the table, in the state of removing the deteriorated layer at the time of casting by finishing the joint surface of the test piece by machining, the test piece is charged into a sputtering device.
After evacuating the inside of the equipment to a high vacuum of 10 ^-6 torr, high-purity Ar gas was introduced to bring the atmospheric pressure to 10 ^-5 torr, and in this state,
The test piece as a cathode, between the anode and the frequency: 13.56MHz,
A high-frequency voltage was applied and discharged under conditions of current density: 0.5 A / cm ² and DC voltage: 1 KV, and the bonding surface was cleaned by bombarding the generated Ar ions for 20 minutes. A brazing material layer having the composition and layer thickness shown in Table 1 is also vapor-deposited on one side or both sides of the joint surface that has been cleaned in step 1, and a metal film is selectively vapor-deposited as shown in Table 1 as well. Then, take it out from the equipment, put it on the normal brazing equipment in a state of stacking it, and apply a load of 0.2 kg / cm ² while applying 10 ^-5 tor.
In a vacuum of r, hold at 1150 ° C for 3 hours, then continue to 1100 ° C for 2 hours.
The methods 1 to 6 of the present invention were carried out by performing liquid phase diffusion bonding under the condition of holding for 4 hours.

In addition, for the purpose of comparison, without forming a brazing material layer and a metal film on the cleaning joint surface by vapor deposition, In place of this, during brazing, the thickness produced by the normal single roll ultra-quenching method between the joining surfaces of the members: 25 μm
Conventional methods 1 to 3 were carried out under the same conditions as in the methods 1 to 6 of the present invention except that the Ni-Cr-B alloy brazing filler metal was used.

Then, for each of the brazing members obtained as a result of this, a joint test piece with a parallel portion of 6 mmφ was cut out from this, and
Creep tests of 100 hours were carried out at 60 ℃ and 982 ℃, respectively, and the creep rupture strength (100
The load at the time of reaching the end of life) was measured. The results are shown in Table 1.

[Effects of the Invention] From the results shown in Table 1, according to the methods 1 to 6 of the present invention,
In any case, it is clear that a joint having a much higher creep strength can be obtained as compared with the conventional methods 1 to 3.

As described above, according to the method of the present invention, γ′-reinforced Ni
Since the brazing material of the Ni-Cr-B alloy has a uniform thickness and adheres to the joint surface of the base heat-resistant alloy member, the liquid phase diffusion between the joint surface and the brazing material during brazing does not occur. Since it is carried out uniformly and in a promoted state over the entire surface, industrially useful effects such as the formation of a joint having high creep strength can be obtained.

Claims (1)

[Claims] 1. A γ'reinforced Ni-based heat-resistant alloy member is made of Ni-Cr-B.
In liquid phase diffusion bonding using a system alloy brazing material, prior to brazing, in an ion plating device or a sputtering device, the bonding surface of the member is cleaned by ion bombardment, and either one of the cleaning bonding surfaces or A brazing material layer of the above Ni-Cr-B alloy is vapor-deposited and formed on both of them, and a metal film of Pd, Pt, Cr, or Cr-Ni alloy is vapor-deposited and formed as a surface layer on any joint surface. A liquid phase diffusion bonding method for a γ'reinforced Ni-based heat resistant alloy member.