SiC_p/6061Al原位合金化焊接增强相界面微结构分析

Microstructure Features of In-situ SiC_p/6061Al in Plasma Arc Welding by New Reinforced Phase

以Al-5Ti-5Si药芯焊丝为填充材料的SiCp/6061铝基复合材料,在交流电弧超声作用下进行等离子弧原位焊接,利用TEM和HRTEM测试手段研究了焊后新生增强相与基体的微界面结构,结果表明:所有新生增强相尺寸都有所减小,并且新生相与铝存在Al3Ti(020)∥Al(002),Al3Ti[001]∥Al[100],AlN[100]∥Al[100]的位相关系。细小的Al3Ti,TiC,Si以及AlN相与基体的结合界面干净无任何反应物生成,与基体Al原子错配度低的新生相还可作为铝的异质形核核心,细化基体晶粒。焊接接头最大抗拉强度为92.69MPa,达到母材强度的62%。

The aluminum matrix composite which reinforced by SiCp particles was added Al-5Ti-5Si as filling material in plasma arc ＂in-situ＂ welding,and the alternating arc-ultrasonic was needed in the welding process.The microstructures at the interfaces were observed by transmission electron microscopy（TEM）and HRTEM.The results show that the sizes of all new reinforced phases become smaller,and such orientation relationships as Al3Ti（020）∥Al（002）,Al3Ti∥Al and AlN∥Al are founded in the joint.There are entire-coherent interface between the Al matrix and the small new reinforced phases of Al3Ti,AlN,Si and TiC,but no resultant production is observed along those interfaces.The Al matrix can grow along the new reinforced phases which have low-dislocation with Al,so the size of Al can be reduced.The mechanical testing results show that the maximum tensile strength of the welded joint is 92.69MPa,which reaches the 62% of the matrix strengths.