Anisotropic properties of Ag/Ti3AlC2 electrical contact materials prepared by equal channel angular pressing

Abstract

Equal channel angular pressing (ECAP) was introduced firstly to prepare Ag/Ti3AlC2 electrical contact materials. Ag/10 wt% Ti3AlC2 composite with a relative density of 99.8% and refined microstructure was prepared by ECAP at a relatively low temperature of 200 °C under 37 MPa. The Ti3AlC2 particles were delaminated and preferentially aligned in Ag matrix after ECAP. The preferential alignment of Ti3AlC2 resulted in the anisotropy in electrical and compressive properties and arc erosion resistance of the composite. The properties of the as-sintered compact and ECAPed sample were tested. The Vickers hardness of the ECAPed sample was about 1.5 times that of the as-sintered compact. The lowest resistivity reached 59.3 × 10−9 Ω m in the ECAPed sample parallel to the alignment. The maximum compressive strength and strain were found to be 805 ± 18.6 MPa and 43.8 ± 2.2% in the ECAPed sample loaded perpendicular to the Ti3AlC2 alignment. The ECAPed sample with working face parallel to the Ti3AlC2 alignment showed the best arc erosion resistance. The mechanisms responsible for the anisotropic microstructure and properties were proposed and discussed.