How to Select the Brazing Fixtures for Vacuum Brazing furnace?

Selection of vacuum brazing fixture materials The most fundamental thing in the selection of fixture materials is to ensure that at the brazing temperature, the rigidity of the fixture material is greater than that of the brazing part material, so during the brazing process, the deformation of the weldment is always limited by the fixture , Weldments and their matching dimensions can be guaranteed by fixture assembly. The working temperature of vacuum aluminum brazing is about 600 ℃, and the brazing time is 3 to 6 hours. Generally, 1Crl8Ni9Ti can meet the requirements of use. 1Crl8Ni9Ti is austenitic stainless steel with oxidation resistance above 700℃. The most important thing is the brazing temperature. It still has enough thermal strength, the rigidity is far greater than that of aluminum alloy, the structure is stable, and it will not be embrittled after long-term screwing. Therefore, it is very suitable to use 1Crl8Ni9Ti for the basic frame and main working parts of the brazing fixture; for some matching dimensions and accuracy For parts with high requirements, the fixture design must involve the thread pair and the positioning hole shaft coordination, the material selection is inappropriate, the structure is close, the thermal stability is poor, there will be “seizure” phenomenon between the fixture parts at the brazing temperature, and the use of cast iron and lCrl8Ni9 Fi can be used interchangeably to solve this problem.

The influence of vacuum brazing fixtures and parts on the brazing process caused by thermal deformation at the brazing temperature should be emphatically considered. Due to the different materials of the fixture and the brazed parts, the coefficient of thermal expansion is different. When heated, there will be a difference in expansion, and the brazed parts will deform. The purpose of the fixture is to make the brazed part deform with the deformation of the fixture. Generally, In other words, there are mainly requirements for the flatness, perpendicularity, and weld gap of brazed parts. For other parts with less stringent requirements, the use of forced deformation fixtures can meet the requirements of use; but for some parts with high requirements on external dimensions and matching dimensional accuracy, the use of forced deformation fixtures cannot meet the use requirements, and must be considered in forced deformation fixtures. Based on the design, some elastic elements are designed to form a flexible fixture system. The elastic elements generally use high-temperature springs or elastic chucks. After the calculation of the expansion difference, the deformation range of the elastic elements is controlled, so that the necessary pressure can be maintained on the brazed parts. It also solves the problem of poor expansion.

Shanghai Geheng Vacuum Technology Co., Ltd. is a vacuum heat treatment furnace manufacturer with many years of experience in design, manufacturing and production. Mainly produce vacuum heat treatment furnace, vacuum sintering furnace, vacuum brazing furnace, New Energy And Environmental Protection Equipment and Vacuum Carbonization Furnace .Provide customized services, equipment work area can be based on customer output.