Nickel-plated SiCp/Al composites brazed in the air: Microstructure and mechanical properties of brazed joints under different processes

Abstract

Abstract 55% SiCp/ZL102 composites were surface metalized by electroless nickel plating. The Al-17Cu-8Mg-2Ni as-cast brazing alloy was treated by an ultra-cold thin strip system using a melt-spinning machine to realize the redistribution of solutes. The obtained foil-like brazing alloy has better flexibility, more uniform element distribution, and higher free energy than the as-cast brazing alloy. The 55% SiCp/ZL102 composites after nickel plating were brazed by different brazing processes in the air. The Ni-P coating effectively inhibited the formation of alumina film on the composite surface. However, the presence of an oxide layer on the foil filler caused a negative effect on the Ni-P coating and hindered the diffusion between elements. SiC, Ni2Al3, and other phases were detected in the joint port. The characteristic morphologies such as furrows and massive particles indicated that the fracture behavior is brittle fracture. The maximum shear strength of the joint was 88.31 MPa at 590°C.