Effect of Ti particles on microstructure and mechanical properties of TiP/AZ91 composites

Ti particles (5 wt%) reinforced AZ91 Mg matrix composites (TiP/AZ91 composites) were prepared by powder metallurgy. As a result, the strength and ductility of TiP/AZ91 composites were improved compared with AZ91 alloy. The ultimate tensile stress (UTS) increased significantly from 163 MPa to 221 MPa, and the elongation increased from 3.5% to 10.9%. The YS and hardness decreased due to the slightly coarser grain size. The microstructural results showed that Ti particles were uniformly dispersed in the Mg matrix and the content of Mg17Al12 was reduced, indicating that Ti particles can inhibit the precipitation of the second phase. The interface between Ti particle and Mg matrix showed that the Al3Ti layer was formed at the edge of the Ti particles. EBSD was used to analyze the twins and dislocations at different tensile strains. During the tensile deformation at room temperature, many tensile twins and dislocations formed in the TiP/AZ91 composites. The tensile twins and dislocations could coordinate plastic deformation, thus improving the elongation of the TiP/AZ91 composites. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).