固溶、时效、深冷处理对QAl9-4铝青铜组织及性能的影响

Effect of solution and aging and cryogenic treatment on microstructure and properties of QAl9-4 aluminum bronze

为改善QAl9-4铝青铜的使用性能,对挤压态QAl9-4铝青铜采用固溶、时效、深冷的热处理工艺,利用布氏硬度、SEM、EDS、光学显微镜等手段分析QAl9-4铝青铜处理前后的显微组织和硬度的变化。结果表明:随着固溶温度的升高,硬度增大,随着时效、深冷次数的增加,布氏硬度略有升高;随着固溶温度的升高,时效、深冷次数的增加,QAl9-4铝青铜显微组织中α固溶体、α+KⅡ共析体增多,β'相减少,晶粒细化,金属基体尺寸更加稳定。在950℃固溶后进行时效+深冷+时效+深冷处理,QAl9-4铝青铜的显微组织和硬度都比较理想。

The processes of solid solution,aging and cryogenic heat treatment were employed to improve the performance of extruded aluminum bronze QAl9-4. Microstructure and mechanical properties of the QAL9-4 alloy by deep cryogenic treatment were analyzed by means of Brinell hardness test,SEM,EDS analysis and optical microscope. The results show that with the solid solution temperature increasing,hardness of the alloy increases. The hardness of the alloy slightly increases after double aging and cryogenic treatments.Increasing the solid solution temperature and after double aging and cryogenic treatments,the amount of α solid solution and eutectoid α +KⅡphases in the QAl9-4 alloy increases,β'phase decreases,and the grain size is refined and the sizes of the matrix are more stable. The better microstructure and hardness of the QAl9-4 alloy can be obtained after solid solution at 950 ℃ and then double aging and cryogenic treatments.