SiC_p/ZL101铝基复合材料的原位强化活性液相扩散焊方法(In situ A-TLP)

In situ active transient liquid phase(In situ A-TLP)bonding of SiC_p/ZL101 aluminum metal matrix composite

提出了一种采用含有升熔型活性元素的三元活性钎料的'原位强化活性液相扩散焊'(In situ A-TLP)方法,并研制出一种可实现该新工艺的Al-Cu-Ti系三元活性钎料。该方法不仅使母材/钎缝界面(包括P/M界面)致密,还能实现钎缝本身的原位强化。突出特点在于后者:一方面在降熔元素Cu向母材扩散而实现等温凝固后,钎缝基体转变为综合性能优良的固溶体;另一方面,升熔型活性元素难以向母材中扩散而在凝固前沿局部处浓度会自动升高,足以在钎缝中通过结晶方式,原位形成含有升熔型活性元素的弥散分布的亚微米或微米级三元金属间化合物强化相;从而获得以亚微米或微米级三元金属间化合物Ti(AlSi)_2为强化相、以固溶体为基体的优质钎缝。在550℃焊接10%的SiC_p/ZL101(体积分数),接头性能达母材的99.7%;断裂路径可穿入母材并非全在界面与钎缝内。

A novel method of in situ active transient liquid phase(A- TLP) bonding with an interlayer containing melting point increaser(MPI) was proposed to join SiC /ZL101 aluminum metal matrix composite.Compared with general TLP joint using copper foil,in situ A-TLP joint using Al-Cu-Ti interlayer exhibits a significant improvement in microstructure and mechanical properties.A large amount of in situ reinforcement phases of Ti(AlSi)_2 form in the brazed seam by means of segregation and precipitation from liquid.The in situ A- TLP joint fracture occurs at SiC_p/ZL101 composite and the joint efficiency reaches 99.7%.The microstructure transition in brazed seam from original microstructure to solid solution is essential for the effectiveness of in situ reinforcing.Otherwise,like general TLP joint using Cu interlayer,the joint fracture occurs preferentially at the brazing seam matrix.