Ni_(82.5)Cr_7Si_(4.5)B_3Fe_3多元非晶态合金钎料的晶化行为及其真空钎焊特性

采用示差扫描量热计(DSC)和X射线衍射方法研究了Ni_(82.5)Cr_7Si_(4.5)B_3Fe_3多元非晶态合金钎料在加热时的晶化特性.实验指出:随加热速率的增大,其晶化特征温度逐渐提高,晶化前所需孕育时间延长,并且晶化后的二次相变过程消失;探讨了该钎料的真空钎焊工艺性能和钎焊接头力学性能,以及预晶化处理对它们的影响,并与相同成分的粉状和粘带状晶态钎料进行了系统的比较.研究结果指出:非晶态钎料在工艺性能方面与晶态钎料相当;在接头力学性能方面则表现为在较大和较小的钎焊间隙下非晶态钎料的钎焊接头性能明显高于晶态钎料.

THE GRYSTALLIZATION BEHAVIOR OF POLYATOMIC AMORPHOUS BRAZING FILLER METAL ALLOY Ni_(82.5)Cr_7Si_(4.5)B_3Fe_3 AND ITS VACUUM BRAZING PERFORMANCE

The crystallization behavior of polyatomic amorphous alloy Ni_(82.5)Cr_7Si_(4.5)B_3Fe_3 in heating is studied by means of differential scanning calorimeter(DSC)and X-Ray diffraction techniques. The experimental results indicate that the characteristic temperatures of crystallization and the inoculation -time before crystallizing increase gradually when the heating rate increases, and the second-time phase transition after crystallizing disappears. The vacuum brazing technological performance and mechanical property of brazed joints on this kind of brazing filler metal as well as the influences of pre-crystallization treatment on above properties have been studied. The systematic comparisons have been done between amorphous brazing filler metal and the crystalline one which are in powder and binder-ribbon forms and have the same chemical composition with the former. The results indicate that amorphous brazing filler metal matchs the crystalline one in vacuum brazing technalogical performance, and under the smaller and larger brazing clearances the amorphous brazing filler metal precedes the crystalline one in mechanical property of brazed joints.