Si含量对经时效处理的C72500合金组织和性能的影响

Effect of Silicon Contents on Microstructure and Property of Aged C72500 Alloy

采用扫描电镜、能谱分析、X射线衍射、电导率和力学性能测试等方法,研究了Si含量(0.10%、0.15%、0.20%、0.25%、0.30%)对时效处理后C72500合金的显微组织、物理性能和力学性能的影响。研究结果表明,Si能细化合金的晶粒,在合金基体中形成Ni_2Si和Ni_(31)Si_(12)相,在时效过程中,Ni_2Si相析出能阻碍晶粒长大并使合金产生时效硬化。经时效处理的合金的电导率和抗拉强度都随合金中Si含量的增加而增大。当合金中Si含量为0.30%(质量分数)时,经400℃×4 h时效处理后的合金的电导率为16.0%IACS,抗拉强度为826 MPa,断后伸长率为6.8%。

Effect of silicon contents sueh as 0. 10%, 0. 15%, 0. 20%, 0. 25% and 0. 30% （by mass） on microstructure, physical and meehanical properties of a C72500 alloy after aging was investigated by means of SEM, EDX, XRD and measurements of both conductivity and meehanieal properties. The results show that the silieon ean render grains of the alloy smaller, and that Ni2Si and Ni31Si12 were formed in the alloy matrix, and precipitation of the Ni2Si phase will hinder the grain growing and cause the alloy to be hardened by aging. In addition, as the silicon content in the alloy increases so too do both the conductivity and tensile strength of the alloy after aging. The C72500 alloy containing 0.30% Si offers conductivity of 16.0% IACS, tensile strength of 826 MPa and elongation of 6.8% after ageing at 400℃ for 4 h.