中文摘要：

研究了固溶处理温度和固溶处理时问对挤压铸造Al17．5Si4Cu0．5Mg0．1Mn合金显微组织及硬度的影响。结果表明：固溶处理后合金的显微组织得到明显改善，硬度大幅度提高。随着固溶温度的增加，共晶Si相逐渐粒化，合金的布氏硬度值逐渐增加，当固溶温度为525℃时，共晶Si相形貌相对圆整，合金具有最大布氏硬度值；随着固溶时间的延长，合金显微组织中的共晶Si4（N发生熔断、粒化、粗化现象，合金的布氏硬度呈现先上升后下降的趋势，当固溶时间为6h时，合金的布氏硬度达到最大值HB124。试验得到的挤压铸造Al17．5Si4Cu0．5Mg0．1Mn合金的最佳固溶处理工艺为525℃，保温时间为6h。

英文摘要：

Effects of solution temperature and solution time on microstructure and hardness of squeeze casting Al17.5Si4Cu0.5Mg0.1Mn alloy were investigated. The results showed that the microstructure of the alloy had been improved obviously and the Brinell hardness of alloy was improved remarkably after solution treatment. With the increase of solution temperature, eutectic Si phase transformed into spheroidization and the Brinell hardness of alloy was increased gradually. The peak value of Brinell hardness of alloy was attained and eutectic Si phase is round when the solution temperature was 525 ℃ ; with the increase of solution time, the change of eutectic Si included three stages which were fragmentation, spheroidization and deterioration of Si particles and the Brinell hardness of alloy increased first and then decreased, when the solution time was 6 11, the Brinell hardness of alloy attained the peak value, HB 124. The best solution temperature and solution time of squeeze casting Al17.5Si4Cu0.5Mg0.1Mn alloywas 525 ℃ and 6 h respectively.