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本文在540—640℃温度范围内,研究了真空热压温度对15%(体积分数)SiCp/2009Al复合材料的微观组织和力学性能的影响.复合材料的致密度随热压温度升高而增加,在580℃达到最大值,高于580℃时下降.TEM界面观察发现:热压温度为540和560℃时复合材料界面结合较弱,界面出现开裂现象;当热压温度为580和600℃时界面清洁、结合较好;当温度高于620℃时,复合材料界面有MgAl_2O_4和Al_4C_3形成.复合材料的强度和塑性均在580℃取得最佳值.拉伸断口观察发现:热压温度低于560℃时,复合材料的断裂以界面脱黏为主;热压温度在580—600℃之间时,复合材料以基体的韧性断裂和颗粒的断裂为主;热压温度高于620℃时,复合材料界面处MgAl_2O_4和Al_4C_3脆性相的形成使界面开裂,复合材料的断裂为基体韧性断裂、界面开裂以及SiC颗粒断裂.
The effect of vacuum hot pressing temperature on the microstructure and mechanical properties of 15% (volume fraction) SiCp / 2009Al composites was studied in the temperature range of 540-640 ℃ .The densities of composites increased with the hot pressing temperature , Reached the maximum at 580 ℃ and decreased above 580 ℃ .TEM interface observation showed that the bonding interface of the composites was weak and the interface was cracked at hot pressing temperature of 540 and 560 ℃. When the hot pressing temperature was 580 ℃ and 600 ℃ When the temperature is higher than 620 ℃, the interface of MgAl_2O_4 and Al_4C_3 are formed.The strength and ductility of the composites are optimized at 580 ℃ .The tensile fracture observation shows that the hot pressing temperature is low At 560 ℃, the fracture of the composites is dominated by interfacial debonding. When the hot pressing temperature is between 580-600 ℃, the ductile fracture and the fracture of the matrix are the main components of the composites. When the hot pressing temperature is higher than 620 ℃ The formation of brittle MgAl_2O_4 and Al_4C_3 interfaces at the interface of the composites leads to the cracking of the interfaces, the fracture of the composites as ductile fracture of the matrix, interface cracking and fracture of the SiC particles.