Microstructure and wear properties of Al–20Si alloy prepared by spray deposition with following continuous extrusion forming technique

Abstract

Spray deposition with following continuous extrusion forming technique (SD-CE) is an innovative manufacturing technique to produce high alloy net-shape products. Al–20Si alloy rods have been fabricated by SD-CE at different extrusion ratio. Microstructure, hardness and wear resistance of the alloy have been investigated in details. The results show that Al–20Si alloy can be refined effectively by SD-CE, and the size and shape of Si particles become fine and spherical with the increasing extrusion ratio. When the extrusion ratio reaches 20:1, fully dense material with uniform distribution of Si particles can be obtained. The Al–20Si alloys fabricated by SD-CE exhibit excellent wear resistance, which can be further improved by large extrusion ratio, due to increasing hardness and density. A mechanically mixed layer containing a considerable amount of oxygen and iron was formed on the worn surface.