The Study Of Low-Melting-Point Filler Metal For Al-Si-Mg Series Alloys Vacuum Brazing

In order to develop the low-melting-point filler metal for Al-Si-Mg series alloys vacuum brazing, the author work out the main adding element according to the theory of vacuum brazing and metallography. The author successfully finds out the affecting rules of the main adding elements such as copper, silicon, nickel to the spreading characteristics, melting point, molten temperature area and shearing strengthen of joint with fewer experiments owing to the orthogonal test. The influence of several main adding elements including magnesium to the microstructure of aluminum brazing filler metal is analyzed with SEM and EDX and several brazing filler metal of moderate property was developed.This result show that the optimal brazing filler metal of the spreading characteristics, melting point, molten temperature area and shearing strengthen can be got through the measuring of the spreading characteristics, melting point, and the mechanical property and the analyzing of the microstructure of the new brazing filler metal and the joint of the vacuum brazing. Through this we make sure the proportion of the main adding elements such as copper, silicon, nickel and magnesium.It was found that the new brazing filler metal has the property of lower melting point, narrower molten temperature area and moderate spreading characteristics and that the joint has good mechanical property when we use it and that it has a certain point of plasticity. It has good technical property for vacuum brazing and cost less so it has a favorable future.