JPS6236800B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a Cu--Mn based alloy brazing material that has excellent wettability and fluidity and can form a high-strength joint with very few defects such as pinholes. Conventionally, silver solder or Cu-Mn alloy brazing filler metals have been used to braze bits and contacts for cutting, rock drilling, and drilling applications that generally require high strength. Particularly recently, the Cu-Mn alloy brazing filler metal mentioned above has attracted attention as a new brazing filler metal to replace silver solder, and has come to be widely used. In particular, it can also be used for fluxless brazing in an inert gas atmosphere. (b) It is cheaper than silver solder or copper solder. (c) High brazing shear strength can be obtained. (d) It has good plastic workability, so it can be easily processed into thin wires and thin plates. This is due to the fact that it has many advantages as a brazing filler metal. For example, the drilling life of rock drilling bits manufactured using the Cu-Mn alloy brazing filler metal is limited by the defects that occur in the brazed part. It is not determined by the cause, but by the wear and tear of the chip. However, since the conventional Cu-Mn alloy brazing filler metal has a significantly high gas solubility during brazing, it is necessary to improve its fluidity and wettability to improve the surroundings of the solder and to improve gas release. However, even if the brazed part is used, it is not possible to prevent the formation of minute pinholes in the brazed part, and as a result, gas or liquid may leak from the brazed part through the pinhole, or cavitation may occur in the brazed part. If the device is used in such an environment, cavitation damage may occur from the pinhole portion. This invention solves the problems of conventional Cu-Mn alloy brazing materials as described above, and exhibits excellent fluidity and wettability during brazing.
After brazing, it is possible to form a high-strength brazed part with almost no pinhole defects.
Provides Cu-Mn alloy brazing filler metal, weight%
Mn: 10-45%, Zn: 1-25%, one or more of Fe, Ni, and Co: 1-15%, one or two of B and Li: 0.001 ~
It is characterized by a Cu-Mn alloy brazing filler metal having a composition of 0.8%, further containing 0.01 to 3% of Al as necessary, and the remainder of Cu and unavoidable impurities. . Next, the reason why the component composition range of the brazing filler metal of the present invention is limited as described above will be explained. (a) Mn The Mn component has the effect of lowering the melting point of the brazing filler metal, but if its content is less than 10%, the melting point of the brazing filler metal will decrease.
If the temperature exceeds 1000℃, the brazing workability will be impaired, while if the content exceeds 45%, it will not only have a melting point of 1000℃ or higher, but also The Mn content was determined to be 10 to 45% because the melting process during production would be difficult and the Mn yield would be extremely low. (b) Zn The Zn component lowers the melting point of the brazing filler metal and
It reduces the solubility of gas in the molten solder during brazing work, and improves the fluidity and wettability of the solder.
Furthermore, it has the effect of preventing oxidation of molten wax,
If the content is less than 1%, the desired effect cannot be obtained; on the other hand, if the content exceeds 25%, the workability in processes such as rolling or wire drawing performed during the manufacture of brazing filler metal may be reduced. Not only that, but also Zn evaporation is likely to occur during brazing, so the content was set at 1 to 25%. (c) Fe, Co, and Ni These components have a uniform effect of improving the heat resistance strength without reducing the ductility of the brazing filler metal, but if their content is less than 1%, the desired effect is not achieved. On the other hand, if the content exceeds 15%, the melting point of the brazing material will exceed 1000℃, which will impede brazing workability, so the content should be reduced from 1 to 25%. It was determined that (d) B and Li These components not only further improve the castability when manufacturing the brazing filler metal, but also prevent oxidation of the solder during brazing, and also remove oxides on the surface of the brazing base material. It has a uniform effect of forced reduction and significantly suppresses the solubility of gas in the molten solder during brazing work, but its content is 0.001%.
If the content is less than 0.001%, the desired castability, oxidation resistance, deoxidation properties, and gas dissolution reducing effect cannot be imparted to the brazing filler metal, so it is necessary to contain more than 0.8%. As the brazing filler metal itself becomes brittle and its workability deteriorates,
Its content was set at 0.001-0.8%. (e) Al Al component improves the oxidation resistance of the solder during brazing, and also has the effect of solid solution strengthening and slight precipitation strengthening, so when better oxidation resistance and high strength are required. If the content is less than 0.01%, the desired effect of improving the above action cannot be obtained, while if the content exceeds 3%, the brazing material itself becomes brittle. As the processability deteriorates,
Its content was determined to be 0.01 to 3%. Next, the Cu--Mn alloy brazing filler metal of the present invention will be explained using examples and comparing with comparative examples. Examples Invention brazing filler metals 1 to 12 and comparative brazing filler metals 1 to 12 having the component compositions shown in Table 1 by ordinary melting method
4 was prepared. The comparative brazing filler metals 1 to 4 do not contain B or Li. Next, for the brazing materials 1 to 12 of the present invention and comparative brazing materials 1 to 4, square plates made of mild steel having dimensions of 50 mm in length x 50 mm in width x 10 mm in thickness were prepared at the brazing temperatures shown in Table 1, respectively. Using flux and applying high-frequency induction heating, each filler metal is raised to a thickness of 3 mm over an area of 30 mm in length x 30 mm in width, and then the surface of the solder is polished by 1 mm, and the center of the solder is heated. Measure the number of pinholes that occur within an area of 10 mm in length x 10 mm in width, and then
In accordance with the above, a solder spread test was conducted using flux, and the spread area of the solder on a JIS/SS41 board was measured. These measurement results are also shown in Table 1. As shown in Table 1, the present invention brazing materials 1 to 12
Both have excellent flow when brazing.

[Table] The solder exhibits high dynamic properties, and there are no pinholes in the solder after brazing, and even if there are, there are very few pinholes. In particular, these property improvement effects are clear from comparisons between Inventive Alloy 1 and Comparative Alloy 3, Inventive Alloy 3 and Comparative Alloy 1, Inventive Alloy 8 and Comparative Alloy 2, and Inventive Alloy 11 and Comparative Alloy 4. It is. As mentioned above, the Cu-Mn alloy brazing filler metal of the present invention can be brazed at a relatively low temperature, exhibits excellent fluidity and wettability during brazing, and also has excellent fluidity and wettability in the brazed part. It has industrially useful properties, such as almost no defects such as pinholes, and only a few defects at all, and high brazing strength.

Claims (1)

[Claims] 1 Mn: 10 to 45%, Zn: 1 to 25%, one or more of Fe, Ni, and Co: 1 to 15%, one of B and Li Or 2 types: 0.001~
A Cu-Mn alloy brazing filler metal without pinhole defects, characterized by having a composition consisting of 0.8%, Cu and unavoidable impurities: (more than % by weight). 2 Mn: 10-45%, Zn: 1-25%, one or more of Fe, Ni, and Co: 1-15%, one or two of B and Li: 0.001-
1. A Cu--Mn based alloy brazing filler metal free from pinhole defects, characterized in that it has a composition consisting of: 0.8%, Al: 0.01-3%, Cu and unavoidable impurities: (weight% or more).