JPH01118394A - Brazing filler metal for joining ti and ti alloy and its forming method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to soldering and liquid phase diffusion bonding, and in particular to T.
The present invention relates to a joining brazing material suitable for joining Ti and Ti alloys and a method for forming the same.

[Conventional technology]

For conventional soldering of Ti and Ti alloys, as discussed in Welding Technology, September 1986, pages 24 to 32, silver thread, aluminum-based, and titanium-based brazing materials are used as joining brazing materials. is used. Also,
In liquid phase diffusion bonding, pure copper,
As described in Japanese Patent Publication No. 55-6476, 0.5~
Zr alloy containing 10.0% Pd or Pt, C
U alloy, Ni alloy, Ag alloy, and Special Publication 1986-34
As described in Japanese Patent No. 915, 32-80% Zr-Cu
Alloys are used.

In order to form these brazing materials or insert materials between the materials to be joined, they are applied to the joint surfaces in the form of foil or powder, or by various coatings.

[Problem that the invention seeks to solve]

The properties of Ti and Ti alloys are significantly degraded by thermal cycling during bonding.

Ti and Ti alloys undergo α-β transformation, and when heated to a temperature higher than that, corrosion resistance and mechanical properties deteriorate.

Further, when subjected to intense processing or exposed to long-term heating, the crystal grains of the base material become coarsened, resulting in a decrease in the ductility of the base material. Furthermore, the atmosphere during bonding is also important.

Ti and Ti alloys release many gases (C, N,
It has a strong affinity with ○, H) and absorbs these gases,
Hardness increases and toughness decreases.

In brazing welding using conventional brazing filler metals and insert materials, and in liquid phase diffusion bonding, when silver thread (partially) or aluminum-based brazing filler metals are used, the joining temperature is high and the mechanical strength of the base material is high. properties deteriorate.

In addition, as in liquid phase diffusion bonding, when heated for a long time, the crystal grains of the base material become coarse and the ductility decreases, or the base material absorbs gas, increasing its hardness and decreasing its toughness. When using an aluminum brazing filler metal, the base metals Ti and T
Although the i-alloy has good corrosion resistance, the corrosion resistance of its joints is poor.

As mentioned above, in the method of forming a brazing filler metal or insert material between materials to be joined, oxide films and impurities such as TiO2 and AlzOs are formed on the joint surfaces of Ti and Ti alloys, which are the materials to be joined. It remains in the bonded area and causes bonding defects and a decrease in bonding strength.

In addition, even when supplied in the form of powder or foil, an oxide film is formed on the surface of the powder and remains at the joint, causing adverse effects.

The purpose of the present invention is to remove the oxide film on the joint surfaces of the materials to be joined, and to suppress the absorption of gas components.

An Al alloy insert material for joining Ti and Ti alloys that can prevent deterioration of mechanical properties and corrosion resistance due to heat cycles during joining of materials to be joined, and improve the corrosion resistance of the joined part, and The objective is to provide a formation method.

[Means for solving problems]

The above purpose is to clean the joint surfaces of the Ti and Ti alloy materials to be joined in advance by dry etching treatment (ion sputtering, glow discharge, etc.), and then clean the joint surfaces in the same container without exposing them to the atmosphere. As a bonding insert material forming process, an Al alloy film containing 0.1 to 5% Pd or Pt is provided by vapor deposition or sputtering, and the bonding surfaces on which the Al alloy film is formed are placed opposite each other. in vacuum (5X IQ-5Torr
This is achieved by low-pressure, low-temperature bonding under conditions (below).

[Effect]

The joining insert material of the present invention and its forming method will be explained with reference to FIG.

First, sputter etching is performed on the joint surface 2 of the materials 1 to be joined, which have been previously processed and ultrasonically cleaned, using Ar+ ions generated from the Ar ion gun 5 to remove the oxide film that is formed or adhered to the joint surface 2.

Adsorbed gas and impurities are removed and a clean surface 3 is provided.

Next, in the same container 7, an Al1 alloy insert layer 4 for bonding is provided on the clean surface 3 provided on the material 1 to be bonded using a magnetron sputtering device @6, and then the material is subjected to bonding.

Cleaning the joint surfaces of Ti and Ti alloys, which are the materials to be joined, is to clean the TiO2 and AlzOs formed on the joint surfaces.
oxide films, adsorbed gases (○, H2N), impurities (C
etc.) can be suppressed from being absorbed into the joint during bonding, thereby preventing the occurrence of joint defects and embrittlement of the joint.

Forming an Af1 alloy insert film for bonding Ti and Ti alloy by vapor deposition or sputtering is as follows:
It is possible to reduce the mixing and absorption of adsorbed gases and impurities compared to conventional brazing filler metal supply methods (powder, foil), and it is possible to prevent the occurrence of bonding defects and embrittlement of the bonded portion.

Next, the insert material for joining Ti and Ti alloy of the present invention will be explained. The joining insert material of the present invention has 0
．． 1 to 5% Pd or Al-Pd alloy containing Pt or Afl-Pt alloy and 0.1 to 5% Pd
Contains % Pd or Pt, 0.5-15%
It is an Al alloy containing at least one of Si, 0.5 to 15% Cu, and 0.1 to 5% Mg.

The Al alloy, which is the insert material for joining Ti and Ti alloys of the present invention, enables low-temperature joining below the α-β transformation temperature of Ti and Ti alloys, and has corrosion resistance that conventional aluminum solders do not have. It is an insert material.

Next, the functions of each component will be described.

Pd and Pt improve the corrosion resistance of the Al and An alloy insert material itself, thereby improving the corrosion resistance of the joint. but,
If the content of Pd and Pt is less than 0.1%, the effect of improving the corrosion resistance of the insert material and its joints will be small. Furthermore, if Pd or Pt is contained in an amount of 5% or more, corrosion resistance is improved, but intermetallic compounds are likely to be formed, and the joint becomes brittle. Furthermore, Pd and Pt
Since it is expensive, it is better to improve corrosion resistance with a small amount.

Si lowers the melting point of the joining insert material, increases fluidity, and improves wettability to the materials to be joined.

If the content is less than 0.5%, no effect will be observed, and if the content is more than 15%, intermetallic compounds will be more likely to be formed and the joint will become brittle.

Cut;! It has the effect of lowering the melting point of the insert material for one cup. If it is less than 0.5%, the effect is small and 15
When the content is higher than %, intermetallic compounds are likely to be generated, and the joint becomes brittle. Moreover, the wettability to the materials to be joined becomes poor.

Mg generates Mg vapor during bonding, and Al20szTiO
Reduces oxides such as 2, improves wettability to materials to be joined, and prevents absorption of oxygen into the joint.

If the content is less than 0.1%, the effect will be small, and if the content is more than 5%, evaporation will increase and contaminate the bonding furnace.

The properties of Ti and Ti alloys deteriorate significantly when subjected to thermal cycles during bonding.

Ti and Ti alloys have an α-β transformation temperature (pure Ti: about 88
If heated above 5°C, the mechanical properties and corrosion resistance will deteriorate. Further, heating at high temperature for a long time as in liquid phase diffusion bonding causes the crystal grains of Ti and Ti alloys to become coarser, resulting in a decrease in ductility. Due to these factors, it is necessary to join Ti and Ti alloys at a low temperature below the α-β transformation temperature. The Af1 alloy, which is the bonding insert material of the present invention, melts at about 660°C or lower, so low-temperature bonding is possible, and the crystal grains of the base material can be coarsened without impairing the mechanical properties or corrosion resistance of the base material. can be suppressed and prevent a decrease in ductility.

The bonded part formed by bonding using the insert material of the present invention becomes a bonding layer containing Pd or Pt, and has inferior corrosion resistance than the base material Ti and Ti alloy.
Corrosion resistance is improved compared to conventional aluminum solder joints.

When joining Ti and Ti alloys, it is necessary to pay attention to the atmosphere at the time of joining. Ti and Ti alloys are active with gaseous components (C, O, N, H) and become hardened and brittle. Therefore, when bonding is performed using the insert material of the present invention, the atmosphere at the time of bonding is preferably a vacuum of 5 x 10-'Torr or less.

The bonding insert material of the present invention can also be applied to bonding Ti and Ti alloys to other dissimilar materials, and to bonding Al and Al alloys.

〔Example〕

An embodiment of the present invention will be described below.

Pure Ti (dimensions: 10 mm opening) was used as the material to be joined. First, ultrasonic cleaning was performed in advance in acetone for a minute using a ladle.

Next, a bonding insert material was formed on the bonding surface of the materials to be bonded using a vacuum device equipped with an Ar ion sputtering device and a magnetron sputter deposition device. First, a bonding surface of pure Ti, which is a material to be bonded, was sputtered using an Ar ion sputtering device in a vacuum apparatus to form a cleaned surface. Table 1 shows Ar ion beam processing conditions.

Table 1 As shown in Table 1, an Ar with an output of 600W (3KV, 200mA) was applied in an Ar atmosphere of 3 x 10-3 Torr.
Approximately 200 people (
10 people/m1n) to remove the oxide film, adsorbed gas, and impurities on the joint surface, and form a clean surface.

Next, a bonding insert material was formed on the clean bonding surface of pure Ti using a magnetron sputtering device provided in the same vacuum device. Table 2 shows the sputter deposition conditions, and Table 3 shows the sputter deposition conditions.
indicates the chemical composition of the joining insert material.

As shown in Table 2, Table 3, 20 m1n(
0.5 μm/win) to form a 12 alloy film shown in Table 3, which is a bonding insert material of about 1 μm.

/Al is the bonding insert material of the present invention formed
As shown in Table 3, the composition of the alloy film is Al-2%Pd alloy, Al-0.8%Pt alloy, Al-2.0%Pd
-10%5i-5%Cu-1,5%Mg alloy and Al2
-0.8%Pt-10%5i-5%Cu-1,5%
It is an Mg alloy. Further, the 12 alloy film, which is a bonding insert material for comparison, was made of pure Al and an Al2-10% alloy.

When the 12 alloy film is formed by sputter deposition without performing Ar ion beam treatment, which is one of the dry etching processes used to form the bonding insert material of the present invention, the 12 alloy film is a pure Ti bond. It peeled off from the surface.

The thickness of the formed bonding agent Q alloy film was kept constant at about 10 μm. The melting points of the 12 alloy film are: Al-2, OPd alloy = 655°C, Al-0,8Pt alloy: 640°C, Al
-2. OPd-1,0%5i-5%Cu-1,5%Mg
Alloy: 550°C, Al-〇, 8%Pt-10%5i
-5% Cu -1, 5% Mg alloy = 560°C, Al:
660°C, Afl-1o%Si alloy: 580°C.

Next, a 12 alloy film (Nα1
~7) They were made to face each other and bonded. Table 4 shows the bonding conditions.

Table 4 Welding is performed using 2×10-δTo which excludes the influence of gas components.
Bonding temperature near 00℃ under vacuum of rr, bonding time: 30m
1n, pressurized crab at 0.1 kgf/mm2.

FIG. 2 shows the bond strength of the pure Ti bond. As shown in FIG. 2, An-2, OPd alloy (NQI).

The bonding strength of the pure Ti bonded portion according to 2) is approximately 16 kgf/nya2 when Ar ion beam treatment is performed, and approximately 6 kgf/nya2 when Ar ion beam treatment is not performed.
It is mm2. It can be seen that the bonding strength of the bonded portion without Ar ion beam treatment is low due to the influence of the oxide film on the bonded surface.

Next, as shown in FIG. 2, the bonding strength of the bonded portion as bonded was compared with the bonding strength of the bonded portion after a 5% Na CQ water immersion test (72 hours). As a result, the bonding strength of the bonded portion using the Al alloy film (Nα1.3, 4.5), which is the insert material of the present invention, was determined by immersion in 5% NaCf1 water (72 hours).
) Although there is a slight tendency to decrease depending on the test, pure Al
It can be seen that the decrease in the bonding strength of the bonded portion is smaller than that of the film (Nα6) and the Al-10%Si film (N(17)).From this, by bonding using the insert material of the present invention, the bonding strength of the bonded portion is reduced by using the insert material of the present invention. It can be seen that the corrosion resistance is better than the conventional one.

〔Effect of the invention〕

According to the present invention, in joining Ti and Ti alloy, α
Since joining can be performed at a temperature below -β transformation temperature, the materials to be joined are not deteriorated, the influence of gas can be eliminated, and the corrosion resistance of the joint is improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a method for forming an insert material according to an embodiment of the present invention, and FIG. 2 is a diagram showing the bonding strength of a joint portion using the insert material of the present invention and a comparative material. 1... Material to be joined, 2... Joining surface, 3... Clean surface,
4... Al alloy insert film for bonding, 5... A'r
Ion gun, 6... Magnetron sputtering device, 7.
...Vacuum container.

Claims (1)

[Claims] 1. 0.1 to 5% Pd as a joining insert alloy
Or Al-pd alloy containing Pt or Al-Pt
A brazing material for joining Ti and Ti alloy, characterized by using an alloy. 2. In claim 1, furthermore, from 0.5 to
A brazing filler metal for joining Ti and Ti alloys, which is an Al alloy containing at least one of 15% Si, 0.5 to 15% Cu, and 0.1 to 5% Mg. 3. In joining Ti and Ti alloy, after cleaning the joining surfaces of Ti and Ti alloy as the materials to be joined by dry etching treatment, a joining insert alloy is applied to the cleaned joining surface by sputter deposition. 1. A method for forming a brazing filler metal for joining Ti and Ti alloys.