强流脉冲电子束处理对过共晶铝硅合金Al-25Si微观组织和耐蚀性的影响  

Microstructure and corrosion resistance of HCPEB-treated hypereutectic Al-25Si

作　　者：郝仪[1] 高波[1] 涂赣峰[1] 李世伟[1] 郝胜智[2] 李旻才[2] 董闯[2] 

机构地区：[1]东北大学材料与冶金学院,沈阳110004 [2]大连理工大学三束材料改性教育部重点实验室,大连116024

出　　处：《核技术》2010年第12期886-890,共5页Nuclear Techniques

基　　金：中央高校基本科研业务费专项资金(N090602009;N100402010);国家十一五科技支撑计划重点项目(2009BAE80B01);教育部博士点新教师基金(200801451082);重点实验室开放课题(DP1050902)资助

摘　　要：用强流脉冲电子束处理过共晶铝硅合金表面,并对Al-25Si合金微观组织形貌、物相及耐蚀性进行分析和测试。结果表明,强流脉冲电子束处理在合金表面诱发的快速熔凝过程实现了铝硅合金表层晶粒细化,粗大初生硅颗粒熔化,硅元素固溶到铝基体中,合金表面成分趋于均匀化分布。截面组织分析指出重熔层(8-9μm)与基体之间有明显界限,致密度提高。24 h盐浸失重法测试中,A1-25Si合金经强流脉冲电子束处理后腐蚀失重减小0.008 g,腐蚀速度降低12.1%,耐蚀性能提高。In the paper, hypereutectic Al-25Si alloy specimens are treated by HCPEB （high current pulsed electron beam） and their microstructure morphology, phase transformation and corrosion resistance are characterized. The results show that grains of the Al-25Si alloy surface are significantly refined owing to rapid melting and solidification during the HCPEB bombardment process. Coarse primary Si melts and Si element dissolves into Al matrix, hence the chemical composition of Al-25Si surface tends to homogenous distribution. Cross-section analysis indicates that remelted layer with high relative density has an obvious boundary with matrix and the thickness of remelted layer is 8-9 μm. In the weight-loss experiment, corrosion weigh loss of HCPEB-treated Al-25Si alloy is reduced by 0.008 g and corrosion rate is decreased 12.1% in 3.5wt% NaCl solution. In summary, the microstructure and corrosion resistance of Al-25Si alloy treated by HCPEB are significantly improved.

关 键 词：强流脉冲电了束 Al—25Si 微观组织 耐蚀性 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TF134[金属学及工艺—金属材料]