JPH0436798B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a silver brazing material used in a vacuum or an atmosphere. [Prior Art] Conventionally, silver solder, gold solder, palladium solder, platinum solder, etc. have been used as metal brazing materials. Among these, silver solder is widely used because it has a relatively low melting point, good workability, and is relatively inexpensive. Especially among silver wax
72Ag-Cu alloy (BAg-8) is widely used in electronic parts, etc., and Ag-Cu with increased or decreased silver content taking into account melting point or price.
alloy is used. [Problems to be solved by the invention] However, since the above Ag-Cu alloy contains 28% (Wt%, the same applies hereinafter) Cu, the temperature may rise depending on the conditions of the brazing atmosphere. There are problems with high-temperature corrosion resistance, which sometimes causes oxidative discoloration, and there are also problems such as acid from pickling treatment remaining on the surface during the plating process after brazing, resulting in surface corrosion. [Means for Solving the Problems] The present invention provides a brazing material by adding Ge and Pd to Ag, and further adding one or more of Fe, Co, and Ni to the brazing material during and after use. It has excellent corrosion resistance in processing steps, sufficient spreadability and wettability, and sufficient brazing tensile strength. First, when Ge is added to Ag, the melting point of the Ag-Ge alloy is lowered. When Ge is less than 0.05%, there is almost no substantial decrease in the melting point, but from 0.05% to 19% Ge, which gives a eutectic composition, the melting point gradually decreases as the amount of Ge added increases. over 19%
Addition of Ge raises the melting point again and Ag
-Ge alloy becomes brittle and mechanical workability is inhibited. When Pd is added to this Ag-Ge alloy, Fe,
The wettability and spreadability on base materials such as Ni, Co, and alloys thereof such as 42Fe-Ni, Kovar, and stainless steel are improved. If the addition amount is less than 0.01%, the effect of the addition is negligible, and if it exceeds 10%, the melting point of the alloy will increase, canceling out the effect of lowering the melting point due to the addition of Ge. However, since the brazing filler metal is an expensive material, in order to obtain the effect of lowering the melting point, considering its economic efficiency, the content should be 0.5% or less. In addition, Fe, Co, and Ni are added to the Ag-Ge-Pd alloy.
By adding a species or two or more species, Fe,
When base metals such as Ca, Ni, and their alloys such as 42Fe-Ni, Kovar, and stainless steel are brazed, the metal structure can be refined and the brazing strength can be improved. Addition of less than 0.01% is equivalent to no effect, and addition of more than 3% makes it difficult for these to form a solid solution with Ag, the main component, so Ge and Pd, which are solid solution with these, must be contained in amounts greater than the upper limit. It is inappropriate to do so. [Example] The following example of the present invention using a ternary system of Ag-Ge-Pd will be described. (1) Ag 97.05% Ge 2.5% Pd 0.45% (2) Ag 92.80% Ge 7.0% Pd 0.2% (3) Tests on melting point, spreading area, and tensile strength of samples with Ag 86.95% Ge 13.0% Pd 0.05% or more The results are shown in Table 1. The spreading test was conducted using a 10 mm square brazing filler metal with a thickness of 0.1 mm at a temperature 40° C. higher than the liquidus temperature of each brazing filler metal in a vacuum or in a hydrogen atmosphere and held for 2 minutes. In addition, brazing tensile strength measurement is performed for each base material, cross section 4
The tests were conducted using an Amsler material testing machine for a mm x 4 mm butt joint. Note that brazing was performed at a temperature 40° C. higher than the liquidus temperature of each brazing filler metal in vacuum or in a hydrogen atmosphere.

[Table] Next, examples of the present invention in which one or more of Fe, Co, and Ni are added to Ag-Ge-Pd will be described. (4) Ag 96.05% Ge 3.0% Pd 0.45% Ni 0.5
% (5) Ag 92.30% Ge 6.0% Pd 0.2% Fe 1.5
% (6) Ag 85.95% Ge 12.0% Pd 0.05% Co
Table 2 shows the test results regarding melting point, spreading area, and tensile strength for samples containing 1.0% Ni or more. Note that these tests are the same as the test methods shown in Table 1 above.

〔Effect of the invention〕

According to the present invention explained above, since it is an alloy mainly composed of Ag-Ge-Pd, it has excellent corrosion resistance at high temperatures, and has sufficient spreadability and wettability.
It has sufficient tensile strength and also solves the problem of corrosion due to acid remaining on the surface due to pickling treatment in the plating process after brazing, making it a silver brazing material that can be used in a wide range of areas. .

[Brief explanation of drawings]

FIG. 1 is a photomicrograph of the surface of the metal structure of the present invention, and FIG. 2 is a photomicrograph of the surface of the Ag-Ge metal structure.

Claims (1)

[Claims] 1. A silver brazing material characterized by containing 0.05 to 19 Wt% of Ge, 0.01 to 0.49 Wt% of Pd, and the balance being Ag. 2 Ge 0.05-19Wt%, Pd 0.01-0.49Wt%, and one or more of Fe, Co, and Ni.
A silver brazing filler metal characterized by containing 0.01 to 3 Wt% and the balance being Ag.