Laser Welding Mechanism and Parameters of Aluminum Matrix Composite SiC_w/6061Al

The weldability of the aluminum matrix composite SiC_w/6061Al by pulse laser welding technique have been studied.The effects of laser output power (P),pulse frequency(f) on the properties of the welded joint has been investigated emphatically,and the microstructure of the welded joint has been analyzed by scanning electron microscopy,X-ray diffraction and transmission electron microscopy.The results show that the defects in the weld such as interface reactant and pore are the key factors to reduce the material weldability.The further investigations reveal that the interfacial reaction of reinforcement/matrix of the composite in the weld is inevitable at laser welding,the reactants are of directivity and grow in the direction of heat flow.The main welding parameter for affecting SiC-Al interface reaction is laser output power,and increasing the pulse frequency can restrain the interfacial reaction to some extent,and the amount of the pore in the weld would decrease or vanish with increasing the laser pulse frequency.On the basis of this,the good weld for the aluminum matrix composite has been obtained by making proper welding processing parameters.