(1. 淮海工学院 机械工程学院,连云港 222005;2. 淮海工学院 人事处,连云港222005;
3. 湖南科技大学 机电学院, 湘潭 411201;4. 湖南大学 材料科学与工程学院,长沙 410082)
摘 要: 采用喷射沉积工艺制备SiCp/Al-Fe-V-Si复合材料,并通过热压和热轧工艺对沉积坯进行致密化;通过高分辨电镜观察其SiC/Al界面形貌,并对比热暴露后的界面形貌。结果表明:复合材料主要存在两种SiC/Al界面,一种是厚度为3 nm左右的晶态Si界面层,且在界面附近的基体中生成细小的Al4C3相;另一种是厚度为5 nm的非晶态SiO2界面层,部分溶解的SiC颗粒向附近Al基体中注入游离态的Si,在界面附近形成Si的浓度梯度;两种界面都具有良好的润湿性,界面结合强度高;经640 ℃热暴露10 h后,SiC/Al界面处生成的粗大Al4C3脆性相降低界面结合强度,从而降低复合材料的力学性能。
关键字: 耐热铝合金;Al-Fe-V-Si复合材料;SiC颗粒;喷射沉积;界面
reinforced with SiC particles
(1. College of Mechanical Engineering, Huaihai Institute of Technology, Lianyungang 222005, China;
2. Department of Human Resource, Huaihai Institute of Technology, Lianyungang 222005, China;
3. College of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
4. College of Materials Science and Engineering, Hunan University, Changsha 410082, China)
Abstract:SiCp/Al-Fe-V-Si composites were prepared by spray deposition, and the as-deposited preforms were hot pressed and subsequently rolled. The SiC/Al interface of the as-rolled composite sheets was observed by high resolution transmission electron microscopy (HRTEM). The results show that there are two kinds of SiC/Al interfaces in the composites. One is crystalline silicon transition layer with about 3 nm in thickness, and some dispersed Al4C3 phases appear in the matrix near the interface. And the other one is amorphous silica layer with about 5 nm in thickness and SiC particles solve partly to inject Si into the matrix, resulting in Si concentration gradient. Both of the two kinds of interfaces are characterized with good wettability, which contributes to the strong bonding between SiC particles and Al matrix. Coarse Al4C3 phases appear at the SiC/Al interface for the composite exposed at 640 ℃ for 10 h, which result in the interface weakening followed by decrease of the composite strength.
Key words: heat resistance aluminium alloy; Al-Fe-V-Si composite; SiC particle; spray deposition; interface