Mg2Si/Al复合材料的组织和力学性能研究

Study on Microstructure and Mechanical Properties of Mg2Si/Al Composites

采用半固态挤压法制备了原位自生的Mg2Si颗粒增强铝基复合材料,研究了它们的组织,同时研究了挤压比压对力学性能的影响。结果表明,当其它制备条件相同时,在255、340和425 MPa条件下制备的半固态挤压Mg2Si/Al复合材料中的α-Al基体和Mg2Si增强相皆出现球化,但与重力铸造复合材料相比,Mg2Si增强相的颗粒尺寸没有明显变化。拉伸测试结果表明,在255 MPa、340 MPa和425 MPa条件下获得的半固态挤压Mg2Si/Al复合材料具有优于重力铸造复合材料的力学性能,其抗拉强度和伸长率分别提高71.88%、53.13%、43.75%和378%、139%、106%。在255 MPa挤压比压下制备的复合材料表现出最优的抗拉强度及伸长率。

In situ autogenerated Mg2Si particle reinforced aluminum matrix composites were prepared by using semi-solid extrusion.The microstruc ture and the effects of specific pressure on the mechanical properties of semi-solid extrusion composites were investigated.The results show that,the Mg2Si reinforcing phases andα-Al matrix in the semi-solid extruded Mg2Si/Al composites with specific pressures of 255 MPa,340 MPa and 425 MPa are both spheroidized,but the particle size of Mg2Si reinforced phase does not change significantly compared with that of casting composite.Tensile test results show that,the semi-solid extrusion composites under the conditions of 255 MPa,340 MPa and 425 MPa have better mechanical properties than that of the casting composite,and the ultimate tensile strengths and elongations enhance by 71.88%,53.13%,43.75%and 378%,139%,106%,respectively.The composite with specific pressure of 255 MPa shows the best tensile strength and elongation.