Tensile and wear properties of as-cast and extruded AZ91-xCNT and AZ91-1B4C-1SiC-xCNT composites

Abstract

Tensile and wear properties of as-cast and extruded AZ91-xCNTs and AZ91-1%B4C-1%SiC-xCNT (x:0.25,0.5,1wt.%) composites were studied. Compared to as-cast AZ91 matrix alloy, hot extruded AZ91-0.25%CNT showed a significant enhancement in UTS (385 MPa) and elongation (16%), with no substantial improvement in wear properties however, the AZ91-xCNT composites containing micron-sized 1%B4C and 1%SiC particles met the lower tensile properties. Interesting wear behaviour was obtained after adding 1wt.%B4C and 1wt.%SiC to AZ91-xCNT where improvement in wear results was considerable. Development in wear properties of the AZ91-1%B4C-1%SiC-xCNT composites can be attributed to the enhanced hardness and reduced coefficient of friction. Wear analyses of two composites exhibited various wear mechanisms, but the abrasion mechanism dominated after CNT addition and hot extrusion at 20 N load.