混合稀土和挤压铸造对ZL305合金组织和性能的影响

采用挤压铸造和重力铸造制备出不同混合稀土含量的ZL305合金,研究了混合稀土含量和挤压铸造对合金微观组织和力学性能的影响。结果表明,在重力铸造下,添加混合稀土对合金晶粒细化效果明显,当添加0.1%的混合稀土时,ZL305合金的综合力学性能达到最佳,抗拉强度增加到227.88MPa,伸长率为6.47%。相比重力铸造,挤压铸造成形的合金组织明显细化,并且合金铸态的抗拉强度和伸长率都明显提高。添加0.2%的混合稀土时,合金的抗拉强度和伸长率最佳,分别为302.35MPa和7.23%。经430℃×10h固溶处理后挤压铸造合金的性能显著提高。

Effects of Mistchmetal and Squeeze Casting on Microstructures and Mechanical Properties of ZL305 Alloy

ZL305 alloy containing Ce and La elements was prepared by squeeze casting and permanent mould casting.The effects of squeeze casting as well as Ce and La mixed additions on the microstructure and mechanical properties of the alloy were analyzed.The results reveal that the Ce and La mixed addition can reduce positively the grain size of ZL305 alloy prepared by permanent mould casting and the mechanical properties reach the satisfied values with 0.1%mixture RE addition,where the tensile strength and elongation are increased to 227.88 MPa and 6.47%,respectively.The squeeze casting process can refine grain size,which are responsible for the improvement of mechanical properties,such as elongation and tensile strength.With 0.2%of mixture RE addition,the tensile strength and elongation are increased to 302.35 MPa and 7.23%,respectively.After T6 solution treatment at 430℃for 10 h,mechanical properties of the squeezed casting alloy are enhanced obviously.