JPS6328717B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a phosphorous copper solder for copper and copper alloys used in a sulfur-containing sulfur atmosphere. [Prior Art] Phosphorus copper solder is widely used as a brazing material for hard soldering of copper and copper alloys because it is inexpensive. However, when a product brazed with phosphor copper braze is used in a sulfur-based atmosphere containing sulfur, the interface with the base material is severely corroded, the brazed part peels off, and it no longer functions as a brazing material. Therefore, the present inventors first determined that phosphorus was 1 to 9% by weight.
%, zinc 0.5 to 45%, and copper 52 to 83.5%, and has excellent sulfidation resistance (see Japanese Patent Laid-Open No. 44491/1983). This brazing filler metal will have better sulfidation resistance if it contains 0.5% or more zinc, but if it contains more than 50% it becomes brittle due to the precipitation of the γ phase. Furthermore, phosphorus is added in an amount of 1 to 9% in order to lower the melting point to 850° C. or less for brazing properties, and the composition range is determined based on the fact that γ phase precipitation occurs at 45% or more zinc. [Problems to be Solved by the Invention] However, when this phosphor copper solder is used to join a base material that is constrained to some extent, for example, a rotor bar and an end ring in a rotor of a squirrel-cage induction motor, It has been found that this method has the disadvantage that micro-cracks occur due to cooling shrinkage in the brazing filler metal, resulting in a decrease in the adhesive strength of the brazed portion. The present invention has been made to improve this drawback. [Means for solving the problems] In order to solve the above problems, the present invention provides phosphorus 1
~9% zinc, 0.5~45% zinc, and 52~83.5% copper, mixed with titanium and/or zirconium in the range of 0.05~1.5% to prevent microcracks. . The reason for determining the lower and upper limits of the amounts of each of the above components is as follows. That is, if the phosphorus content is less than 1%, the melting point increases, and 9
If it exceeds %, it becomes brittle. Moreover, if the zinc content exceeds 45%, the amount of γ phase precipitated increases and becomes brittle, while if it is less than 0.5%, the melting point is high and it is not convenient to use as a brazing material. Furthermore, when Ti, Zr or Ti+Zr exceeds 1.5%, many nests are observed, the strength decreases,
If the content is less than 0.05%, the crystal refinement effect will not occur, so it is determined as above. Note that copper is determined based on the relationship with the amounts of other components. [Operation] A brazing material made of copper with phosphorus or zinc added contains a small amount of liquid in its solid crystals before it changes from liquid to solid during brazing. If an external force is applied in this state (that is, the brazed part is restrained), cracks will occur from the liquid part. Adding titanium or zirconium increases the number of locations where liquid exists (refining crystal grains), which allows for stress dispersion.
Microcracks will no longer occur. [Examples] Examples of the present invention will be described below. As shown in Table 1, phosphorus 1 to 9% by weight,
Twenty types of brazing filler metals were produced by adding titanium and zirconium either singly or simultaneously to a brazing filler metal consisting of 0.5 to 45% zinc and 52 to 83.5% copper. For comparison, phosphorus 1 to 9 in weight% as shown in Table 1
%, zinc, and 0.5 to 45% copper as the balance. Then, each brazing filler metal was used to braze two 10 mm round copper rods fixed together with a 0.3 mm joint gap, and a tensile test was conducted on each test piece. The results are shown in Table 1. The brazing procedure involved preheating the base metal with a burner to 50 to 100°C, just above the melting point of the brazing material, and then brazing. For brazing filler metals containing 1% or more of zinc, flux (borax + boric acid) was used.

【table】

〔Effect of the invention〕

As described above, the phosphorous copper solder according to the present invention has the advantage that even if the base material is restrained, it does not generate microcracks, has good workability, and can be provided at a low price. It is known that adding Ag to Cu-P brazing filler metal improves workability and strength, and that adding Sn lowers the melting point. If phosphorus is added to copper solder, the range of applications can be further expanded.

[Brief explanation of the drawing]

Figure 1 shows Ti, Zr, Ti+ in the embodiment of the present invention.
It is a graph showing the relationship between the amount of Zr added and tensile strength.

Claims (1)

[Claims] 1% by weight phosphorus 1-9%, zinc 0.5-45%, copper
A phosphorous copper solder having a composition of 52 to 83.5% and 0.05 to 1.5% of titanium and/or zirconium.