Wear resistant aluminum alloy - B4C composites fabricated by rheo-casting and rolling process

Abstract

To reveal the formation and wear mechanisms of rheo-formed aluminum alloy - B4C composites, A356 alloy - 10 mass% B4C composite material was fabricated by semi-solid stirring rheo-casting and rolling process. The presence of Al3BC was confirmed by XRD analysis and hinted that chemical bonding formed at interfaces between aluminum matrix and B4C particles. Tensile test results demonstrated that addition of B4C facilitated improving the tensile strength by refining matrix and providing particle strengthening. Failure tests revealed that the failure type of the composite transferred from interfacial debonding to particle cracking with increasing wear load. The wear rate of the composite was approximately 48% lower than that of aluminum alloy under 60 N load. The friction coefficient of the composite under 60 N load also significantly decreased due to formation of B2O3 and H3BO3 as solid lubricants.