搅拌铸造SiC_p/2024铝基复合材料的显微组织与力学性能  

Microstructures and mechanical properties of SiC_p/2024 aluminum matrix composite synthesized by stir casting

作　　者：苏海[1] 高文理[1] 毛成[1] 张辉[1] 刘洪波[1] 卢健[2] 陆政[2] 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]北京航空材料研究院,北京100095

出　　处：《中国有色金属学报》2010年第2期217-225,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2008CB617608;2009CB623704);国家自然科学基金资助项目(50771043)

摘　　要：利用搅拌铸造?热挤压工艺制备SiCp/2024铝基复合材料板材,研究该复合材料铸态、热挤压态和热处理态的显微组织及力学性能。结果表明:SiC颗粒较均匀地分布于铸锭中,大部分SiC颗粒沿晶界分布,少数颗粒分布于晶内,晶界粗大的第二相呈非连续状分布;复合材料经热挤压变形后,显微孔洞等铸造缺陷明显消除,破碎的晶界第二相及SiC颗粒沿热挤压方向呈流线分布,复合材料的强度和塑性显著提高;对热挤压板材进行(495℃,1h)固溶处理+(177℃,8h)时效处理后,其抗拉强度达430MPa,此时的主要析出强化相为S′(Al2CuMg);热挤压变形有利于改善SiC颗粒与基体合金的界面结合,热处理SiCp/2024铝基复合材料的主要断裂方式为基体合金的延性断裂、SiC颗粒断裂和SiC/Al的界面脱粘。SiCp/2024 aluminum matrix composite plates were prepared by stir casting and hot extrusion process. The microstructures and mechanical properties of the as-cast, as-hot extruded and as-heat treated SiCp/2024 aluminum matrix composite were investigated. The results show that SiC particles distribute uniformly in the as-cast composite ingot, most of which distribute along the grain boundaries, few locate inside the grains, the coarse secondary phases along the grain boundary distribute in discontinuity. After the hot extrusion process, most of the casting defects in the as-cast composite are eliminated. The broken eutectic phases and SiC particles distribute along the flowing direction of the metal plastic. The strength and ductility of SiCp/2024 aluminum matrix composite increase obviously after hot extrusion. Under the condition of （495 ℃, 1h）＋（177℃, 8 h）, the strength of the as-extruded composite plates can reach 430 MPa, S＇（Al2CuMg） phase is the main precipitate at this stage. The tensile fracture surface results show that the hot extrusion deformation is helpful to improve the bonding of the SiC/Al interface. The main fracture manner of SiCp/2024 aluminum matrix composite after heat treatment is ductile failure of the alloy matrix, SiC fracture and debonding of the SiC/Al interface.

关 键 词：铝基复合材料 搅拌铸造 热挤压 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]