Effect of Ti particles size on the microstructure and mechanical properties of TiP/VW94 composites

In the field of magnesium matrix composites (MMCs), it is vital to improve the strength of MMCs without sacrificing plasticity. In this work, TiP/VW94 composites with different Ti particle sizes were prepared by semi-solid stirring assisted ultrasonic vibration method and then subjected to homogenizing treatment. The microstructure results show that the Ti particles are conducive to forming the RE-rich phase. The Mn atoms diffused to the edge of Ti particles, and a submicron layer of MnTi formed at Mg/Ti interface. The atomic spacing misfit at the Mg/MnTi interface is 2.8%, indicating that a strong interfacial bonding was formed at the Mg/Ti interface. The tensile test results show that the strength and elongation all improved after adding Ti particles and improved first and then declined with the decrease of fine Ti particles and the increase of coarse Ti particles. The YS of D3 sample with 2.5% fine Ti particles and 1% coarse Ti particles increased by 12%, the UTS increased by 21%, and the elongation increased by 48% compared with the VW94 matrix alloy.