Pr对Mg-4Si中初生Mg_2Si相变质作用  

Modified primary Mg_2Si phase in Mg-4Si alloy by Pr

作　　者：杨芳[1] 孙治国[1] 张光[1] 徐健博[1] 

机构地区：[1]辽宁工程技术大学材料科学与工程学院,辽宁阜新123000

出　　处：《辽宁工程技术大学学报（自然科学版）》2014年第12期1649-1653,共5页Journal of Liaoning Technical University (Natural Science)

摘　　要：利用稀土元素Pr对过共晶Mg-4Si合金中的初生Mg2Si相进行变质处理,并讨论其变质机理.结果表明:Pr对Mg-4Si中的初生Mg2Si相可以起到有效的变质作用,在Pr质量分数为3%时,变质效果最佳;随着Pr的加入,初生Mg2Si相形态上从花瓣状的树枝晶转变为颗粒状的多边形,尺寸由200μm降到60μm;随着Pr的加入,有白亮的纤维状新相生成,经EDS分析该相为Pr2Si3相;Pr通过表面溶质富集抑制初生Mg2Si相择优生长,Pr2Si3相起到异质形核作用,从而对初生Mg2Si相变质.The hypereutectic Mg-4Si alloy was modified by rare earth Pr, and its modification mechanism was discussed. The result show that Pr can play a role which modifies primary MgaSi in Mg-4Si alloy effectively. When the Pr content is of 3%, the modification is the best. With the join of Pr, the primary Mg2Si phase transition from the petal-like dendrites to granular polygons on morphology, the size from 200 μm down to 60 μm. With the join of Pr, bright white fibrous phase appeared, which is Pr2Si3 by EDS analysis. Pr concentration through the surface of primary Mg2Si which inhibit the growth. Pr2Si3 can be nucleation phase. Thus the primary Mg2Si was modified.

关 键 词：Mg-4Si合金 强化相 变质 初生Mg2Si相 Pr2Si3相 异质形核 

分 类 号：TG146.2[一般工业技术—材料科学与工程]