Investigation of mechanical properties of SiC-reinforced seamless aluminium pipes fabricated using powder metallurgy followed by hot extrusion

Abstract

In this study, SiC (0, 5, 10, 15, 20 wt.%) reinforced seamless aluminium pipes were fabricated using powder metallurgy followed by hot extrusion. The microstructural (optical microscopy, scanning electron microscopy) and mechanical (tensile and crush behaviour) properties of silicon carbide reinforced seamless aluminium pipes were studied. Experimental results showed that the SiC particles form some clusters in the Al matrix and were oriented in the direction of extrusion. Tensile tests indicated that the addition of SiC particles to pure Al matrix resulted in a significant increase in tensile properties of the SiC-reinforced seamless aluminium pipes. Compared to pure Al pipe, 20 % SiC reinforced aluminium pipe exhibited higher yield strength (127 vs. 83 MPa, increased by ∼53 %) and ultimate tensile strength (150 vs. 129 MPa, increased by ∼16 %). Two types of deformation mode (symmetrical ring and asymmetric diamond) were observed in the samples with L/D:1 and L/D:2 ratios under crushing load. Maximum initial collapse force (6.7 kN) was obtained in 10 % SiC reinforced aluminium pipe with L/D:1 ratio.