微量元素Sc对ZA27合金组织与性能的影响.pdfVIP

学兔兔 ．Jan．2010 铸 造 V01．59 NO．1 FOUNDRY · 67 · 微量元素Sc对ZA27合金组织与性能的影响 向青春，徐向阳，侯丽娜，李荣德，袁晓光 (沈阳工业大学材料科学与工程学院，辽宁沈阳110178) 摘要：试验研究了微量元素sc对ZA27合金铸态显微组织与力学性能的影响规律。试验结果表明：单独添加合金元素 Sc，在Sc的加入量为0．5％时，ZA27合金铸态显微组织细化效果较好，粗大的树枝晶组织转变为均匀、细小的团絮状组 织，晶界共晶体组织变得更为细小。合金的铸态抗拉强度和硬度分别达到了495MPa和HBI20．2，伸长率达到7．6％。元 素sc在ZA27合金中与A1形成了与基体晶格类型和晶胞尺寸极为相近的AI，sc粒子，起到了促进异质形核和细晶强化的作 用，从而提高了合金的力学性能。 关键词：ZA27合金；Sc；细晶强化；力学性能 中图分类号：TG146．1 文献标识码：A 文章编号：1001—4977(2010)01—0067—04 Effects of Trace Scandium On MicrostructUre and Properties Of zA27 Alloy XIANG Qing—chun，XU Xiang-yang，HOU Li-na，LI Rong—de，YUAN Xiao-guang (School of Materials Science and Engineering，Shenyang University of Technology， Shenyang 1 1 01 78，Liaoning，China) Abstract：The experiment was carried out to investigate the influences of trace scandium on the m icrostructure and mechanical properties of as．cast ZA27 alloy．The results show that with 0．5％ Sc addition only．the refinement result of the as．cast ZA27 alloy is beRer．The coarse dendrites of the ZA27 alloy are refined and transfo·rmed to the uniform and smalI floccus microstructure，and the eutectics among the grain boundaries become finer．The tensile strength of the as．cast alloy is up to 495 MPa． and the hardness is up to HB 120．2，while the elongation is 7．6％．1n the ZA27 alloy，the trace element of Sc combines with AI to form the AI3Sc particles。the Iattice(LI~type)and the celI size of which are extremely similar to the AI matrix．So these particles become the cores of heterOgeneOus nucleation， refining the microstructure of the alloy and improving the properties of the alloy．