超声波搅拌时间对原位自生Mg_2Si/Al基复合材料凝固组织和力学性能的影响  

Effect of Ultrasonic Stirring Time on Solidification Microstructure and Mechanical Properties of In-situ Mg_2Si/Al Composite

作　　者：白光珠 余昭福 刘政[2] 

机构地区：[1]江西理工大学材料科学与工程学院,江西赣州341000 [2]江西理工大学机电工程学院,江西赣州341000

出　　处：《有色金属材料与工程》2016年第2期14-20,共7页Nonferrous Metal Materials and Engineering

基　　金：国家自然科学基金项目(51361012);江西省自然科学基金项目(20114bab206014);江西省教育厅重点科技项目(GJJ11021)

摘　　要：为了研究铝基复合材料的凝固组织和力学性能,采用超声波搅拌的方法制备了原位自生Mg_2Si/Al基复合材料.利用X射线衍射仪(XRD)、金相显微镜(OM)和扫描电子显微镜(SEM)分析其微观形貌,并通过硬度检测和拉伸试验测试其力学性能.结果表明:超声波搅拌不但能够细化初生Mg_2Si颗粒,改变凝固组织形貌,而且具有除气除杂功能,二者共同提高了Mg_2Si/Al基复合材料的力学性能;经过超声波搅拌的Mg_2Si/Al基复合材料与未经过超声波搅拌的Mg_2Si/Al基复合材料相比,抗拉强度与伸长率总体呈上升趋势,其断口形貌均为准解理面.在超声时间为40s时,抗拉强度和伸长率达到最大值,分别为201MPa和5.63%,相比未超声处理的Mg_2Si/Al基复合材料的抗拉强度和伸长率,分别增长了139.29%和178.71%;复合材料的硬度先升高后降低,超声作用时间为30s时硬度最佳,为116.96(HB).In order to investigate the solidified microstructure and mechanical properties of aluminum matrix composites, in-situ Mg2Si/Al composite was prepared by ultrasonic stirring technique. XRD, OM and SEM were employed to analyze the microstructure of the composites. Mechanical properties of in-situ Mg2Si/Al composite were tested via hardness test and tensile experiment. The results indicated that the ultrasonic stirring not only refined the primary Mg2Si particle to improve the solidified microstructure, but also removed gas and impurity from the Mg2 Si/Al melt. The mechanical properties of the Mg2 Si/Al composites were therefore improved. The tensile strength and elongation of in-situ Mg2Si/Al composite increased with ultrasonic stirring higher than without and the fracture morphology were quasi cleavage surface. Some conclusions were reached in this experiment., the tensile strength of the composite reached at 178 MPa and the elongation of the composite reached at 4.94% respectively as the ultrasonic stirring time was 40 s. The tensile strength and elongation with and without ultrasonic stirring of in-sitg Mg2Si/Al composite were compared which were increased by 139.29% and 178.71% respectively. Meanwhile, the hardness of the composite increased at first and then decreased, which reached the best（116.96） as the ultrasonic stirring time was 30 s.

关 键 词：复合材料 MG2SI 超声波搅拌时间 力学性能 断口形貌 

分 类 号：TB333[一般工业技术—材料科学与工程]