碳化硅颗粒和界面脱粘对SiCP/Al复合材料变形行为的影响
Effects of SiC Particles and Interfacial Decohesion on the Deformation Behavior in SiCP/Al Composites
作者：程南璞(中南大学 材料科学与工程学院，湖南 长沙410083)；曾苏民(中南大学 材料科学与工程学院，湖南 长沙410083)；于文斌(中南大学 材料科学与工程学院，湖南 长沙410083)
Author：(School of Materials Sci. and Eng.,Central South Univ.,Changsha 410083,China)；(School of Materials Sci. and Eng.,Central South Univ.,Changsha 410083,China)；(School of Materials Sci. and Eng.,Central South Univ.,Changsha 410083,China)
收稿日期：2006-04-17 年卷（期）页码：2006,38(6):92-97
期刊名称：工程科学与技术
Journal Name：Advanced Engineering Sciences
关键字：SiCP/Al复合材料;变形;等效介质模型
Key words：SiCP/Al composite;deformation behavior;EMA model
基金项目：国家自然科学基金资助项目(10147207);重庆市科委科技计划资助项目（院士基金：2004DE4002）
中文摘要
为研究SiC颗粒增强铝基复合材料的强化与断裂模式，采用修正的等效介质模型定量计算加入碳化硅颗粒后基体组织变化、颗粒尺寸分布和界面脱粘对12%的SiC(5 μm)/Al（体积分数）复合材料的弹塑性变形的影响。理论计算与实验获得的应力-应变关系符合得较好，研究表明,碳化硅颗粒加入后，基体载荷转移、基体晶粒细化和因热错配造成的高密度位错提高了复合材料的流动应力，界面脱粘则降低复合材料的流动应力；载荷转移、晶粒细化、位错强化是SiCP(5 μm)/Al复合材料的主要强化机制，而界面脱粘、基体韧性断裂是其主要的断裂模式。
英文摘要
A modified effective medium assumption (EMA) model was adapted to quantitatively calculate the effects of matrix properties, size distribution of silicon carbide particles and interfacial decohesion on the elastoplastic deformation behavior in Al matrix composites reinforced by SiC particles with average size 5 μm and volume fraction 12%. The theoretical results coincided well with the stress strain correlation obtained from experiment. The current research indicated that loading transfer from matrix to reinforcement, grain refinement in matrix and high density dislocation originating from difference of thermal expansion coefficient between SiC particles and Al matrix heighten the flow stress of the composites, but interfacial decohesion is opposite. The loading transfer, grain refinement and dislocation strengthening are the main strengthening mechanism of 12%SiC(5 μm)/Al composites, and interfacial decohesion and ductile fracture of Al matrix are the dominating fracture modes in the composites.
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