热轧道次对纳米SiC颗粒增强Mg-9Al复合材料薄板显微组织和力学性能的影响  

Effect of multi-pass hot rolling on microstructure and mechanical properties of thin nano-SiC_p/Mg-9Al composites sheet

作　　者：李刚 李明 王红霞 张增耀 娄菊红[3] 赵兴国 LI Gang;LI Ming;WANG Hong-xia;ZHANG Zeng-yao;LOU Ju-hong;ZHAO Xing-guol(Shanxi Key Laboratory of Advanced Magnesium-Based Materials,School of Materials Science and Engineering,Shanxi 030024,China;Taiyuan Institute of Technology,Taiytuan 030008,China;Southwest Technique and Engineering Institute,Chongqing 400039,China)

机构地区：[1]先进镁基材料山西省重点实验材料科学与工程学院,山西太原030024 [2]西南技术工程研究所,重庆400039 [3]太原工业学院,山西太原030008

出　　处：《轻合金加工技术》2018年第11期34-40,共7页Light Alloy Fabrication Technology

基　　金：山西省自然科学基金(201701D121045);国家自然基金青年基金(51301118);先进镁基材料山西省重点实验室开放课题资助项目(AMM-2016-12).

摘　　要：采用粉末热压法制备了纳米SiC质量分数为7. 5%的SiC_p/Mg-9Al复合材料薄板。通过对复合材料进行小压下量的多道次热轧,研究了热轧道次对其显微组织和力学性能的影响。结果表明:随着轧制道次的增加,晶粒尺寸越来越细小; SiC颗粒的分布也变得更加均匀,同时部分SiC颗粒嵌入原始镁颗粒中,硬度较高的SiC颗粒阻碍了相对较软的镁颗粒的移动,使得SiC颗粒-基体界面附近的位错密度增大和SiC颗粒和镁基体之间的结合增强。复合材料的抗拉强度和屈服强度也随着轧制道次的增加而增加,当轧制道次进行到6道次时,总变形量约为50%,获得相对最优的综合力学性能,抗拉强度为292. 5 N/mm2,屈服强度为252 N/mm2,伸长率为3%。复合材料的强度主要取决于晶粒尺寸、SiC颗粒的分布以及增强相和基体的结合程度。Thin Mg-9wt. % A1 magnesium alloy sheets reinforced with 7.5wt. % SiC nanop- articles were successfully fabricated by hot-pressing of powder （HPP） and muhi-pass rolling with lowered temperature and a fixed reduction between successive passes. The effect of multi-pass hot rolling on the mierostructure and mechanical properties of thin n-SiCp/Mg-9A1 composites sheet was investigated. The results show that the grain size is gradually refined with the increase of rolling passes, the distribution of SiC particles becomes more uniform. Moreover,part of SiC particles inserts into original Mg particles and hard SiC particles im- pede the motion of the soft Mg matrix, thereby increasing the dislocation density near the ma- trix-reinforcement interfaces and enhancing the bonding between the SiC particles and the Mg matrix. The tensile strength and yield strength of the composites are also imnroved with the increase of the rolling passes. When the rolling passes reach 6, the total deformation is about 50%, and the relative optimal mechanical properties are obtained： the tensile strength is 292.5 N/mm2, the yield strength is 252 N/mm2 and the elongation is 3%. The strength of, the composites depends mainly on the grain size, the distribution of the SiC particles, and the degree of bonding between the strengthening phase and the matrix.

关 键 词：粉末热压 镁基复合材料 轧制 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]