Interfacial reactions and bending strength of SiC/A356/FeNi50 composite fabricated by gas pressure infiltration

The SiC/A356/FeNi50 composite was fabricated by gas pressure infiltration. The interfacial region of the SiC/A356/FeNi50 composite consisted of FeNi50 reaction layer, Al reaction layer and Al alloy matrix. The main intermetallic compounds were (Fe,Ni)4(Al,Si)13 and (Fe,Ni)2(Al,Si)5 at the Al reaction layer and FeNi50 reaction layer, respectively. The bending behavior versus different infiltration temperatures and holding times was also investigated. The bending strength at 670 °C was the highest and close to the bending strength of Al alloy (223 MPa), and 46% of SiC/A356. The brittle intermetallic compounds existing at the interface induced the decreasing of the bending strength. The pores were reduced by adequate heating time due to the homogeneous temperature of preform, which was beneficial to improve the bending strength of the composite.