固溶对Ti@(Al-Si-Ti)_p/A356复合材料组织和性能的影响

Effects of Solution Temperature on the Microstructure and Mechanical Properties of Ti@(Al-Si-Ti)_p/A356 Composites

研究了固溶温度对粉末触变成形制备的Ti@(Al-Si-Ti)_p/A356复合材料组织和力学性能的影响。结果表明,随着固溶温度提高,初生相颗粒尺寸变化不大,形状变得不规则;共晶Si相不断固溶入基体,余下的共晶Si颗粒圆整,之后粗化;增强相颗粒的钛芯持续反应减缓,壳层增厚,壳层物相由τ_1相转变为(Al,Si)_3Ti相。复合材料的力学性能随固溶温度先升后降。固溶温度为530℃时,复合材料的抗拉强度、屈服强度、伸长率、维氏硬度(HV)分别为297 MPa,386 MPa,9.6%,94.8。

The effects of solution temperature on the microstructure and mechanical properties were investigated of the core-shell structured Ti@（Al-Si-Ti）p/A356Al matrix composites prepared by powder thixoforming.The results reveal that with the solution temperature increase,the primary phase particles are coarsened gradually and the shape become irregular.Eutectic Si phase is continuously dissolved into the matrix,and the residual eutectic Si particles are spheroidized and then coarsened.Ti core of the coreshell structured reinforced particles is continued to react while the shell layer is thickened,and the phase in shell is transformed from the＂1phase to the（Al,Si）3Ti phase.The mechanical properties of the composites are increased firstly and then reduced with the solution temperature increase.At the solution temperature of 530℃,the tensile strength,yield strength,elongation and Vickers hardness of the composites reach 386 MPa,297 MPa,9.6%and 94.8HV,respectively.