论文部分内容阅读
铸造金属基复合材料的凝固决定着材料的机械性能。本文中研究了凝固冷却速率对ＣＦ／Ａｌ－４．５Ｃｕ复合材料的显微组织、偏析及机械性能的影响。实验结果表明，挤压铸造ＣＦ／Ａｌ－４．５Ｃｕ复合材料凝固过程中，α－Ａｌ相首先在纤维间隙中开始形核，并逐渐向纤维表面生长，而共晶θ－Ａｌ２Ｃｕ相依附ＣＦ表面形核并长大。随着凝固冷却速率的降低，θ相的形态从块状转变为颗粒状，析出量逐渐减少，Ｃｕ元素显微偏析逐渐降低，复合材料的抗弯强度逐渐提高。另外，ＣＦ／Ａｌ－４．５Ｃｕ复合材料由于其强的界面结合力，其断裂特征为脆性断裂，断口形貌表现为平切型
Solidification of cast metal matrix composites determines the mechanical properties of the material. In this paper, the effects of solidification cooling rate on microstructure, segregation and mechanical properties of CF / Al-4.5Cu composites were studied. The experimental results show that during the solidification process of CF / Al-4.5Cu composite, the α-Al phase begins to nucleate in the fiber interspace and gradually grow to the fiber surface, while the eutectic θ-Al2Cu phase-adheres to the CF surface Nucleate and grow. With the decrease of solidification cooling rate, the morphology of θ phase changed from massive to granular, and the amount of precipitates gradually decreased. The micro segregation of Cu gradually decreased, and the bending strength of composites gradually increased. In addition, the fracture characteristics of CF / Al-4.5Cu composites due to their strong interfacial adhesion are brittle fracture and the fracture morphology is flat type