Fabrication of tungsten particles reinforced aluminum matrix composites using multi-pass friction stir processing: Evaluation of microstructural, mechanical and electrical behavior

In this paper, tungsten particles were dispersed into 1060 Al matrix by multi-pass friction stir processing (FSP) to fabricate W/1060Al composites. The effects of the number of FSP passes on the microstructure, mechanical properties and electrical resistivity were investigated. Microstructural observations revealed that increasing the number of FSP passes contributed to W uniform distribution and grain refinement without changing the size and morphology of W particles. Detailed interfacial microstructure analysis indicated that an excellent metallurgical bonding consisting of an element solid solution was formed at the W/Al interface. The mechanical test results showed that, as the number of FSP passes increased, the microhardness values were remarkably enhanced with a more uniform distribution and at the same time both the strength and ductility of FSPed composites were also improved. The maximum microhardness, strength and ductility were achieved in 5-pass FSPed composite reaching to approximate 86 HV, 126 MPa and 24%, respectively. It was also found that the W particles reinforced Al composites exhibited excellent electrical conductivity and increasing the number of FSP passes caused a negligible enhancement in the electrical resistivity of FSPed composites.