挤压后SiC_P／Al─1．45wt％Cu金属基复合材料的微断裂机理  

Microfracture Mechanisms in a Particle-Reinforced Aluminum Alloy Metal Matrix Composite

作　　者：万韬俞[1] 张以增[1] 

机构地区：[1]华中理工大学材料科学与工程系

出　　处：《材料工程》1996年第9期6-8,共3页Journal of Materials Engineering

摘　　要：从粉末法ＳｉＣ_Ｐ／Ａｌ－１．４５ｗｔ％Ｃｕ复合材料原位单轴拉伸变形过程的扫描电镜动态观察入手，研究在拉伸载荷下复合材料的变形和微断裂机理。发现裂纹在强化相与基体的界面上形成，并引起界面分离。随应力增加，在许多更小ＳｉＣ粒子与基体的界面上裂纹张开位移明显增加。最终断裂由多重裂纹扩展和局部化裂纹聚结引起。ＳｉＣ粒子加入将增强对基体塑性的约束。这将抑止裂纹在基体中的扩展，特别是最终断裂前局部化裂纹的聚结。建议进一步的工作应同断裂前材料组织中微损失积累分析相联系。Deformation and microfracture mechanisms in a particle-reinforced aluminum alloys metal matrix composite were studied by in-site tensile dynamic SEM observation.It was found that crack appears in interface layer and leads to debonding.As the load is further increased the crack-opening displacement in the interface is increased while amount of cracks appear in interface between metal matrix and smaller SiC particles.Terminal fracture of the specimen is caused by multiple fracturing and link-up of selected microcracks.Cracks in the aluminum matrix are blunted,which affects coalescence of the local crack before terminal fracture of specimen.This could be attributed to more complex plastic constraint in higher SiC particles content in the matrix.It was also suggested that the further work should be related to statistical addition anlysising of microcrack system in the materials.

关 键 词：金属基 复合材料 微断裂机理 塑性约束 

分 类 号：TB331[一般工业技术—材料科学与工程]