钪对铸态Al-Cu-Mg-Ag-Zr合金组织与性能影响  

Effect of Sc on the microstructure and properties of as-cast Al-Cu-Mg-Ag-Zr alloys

作　　者：肖代红[1] 宋旼[1] 张福勤[1] 陈康华[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《中国科技论文在线》2009年第4期239-242,共4页

基　　金：中国博士后科学基金特别资助项目(200801348);国家重点基础研究发展计划资助项目(G2005CB623704)

摘　　要：采用熔炼铸造方法,制备了不同Sc含量的Al-Cu-Mg-Ag-Zr合金。通过金相、扫描电镜、透射电镜、性能测试等实验方法,研究了Sc对铸态Al-5.3Cu-0.8Mg-0.6Ag-0.2Zr(质量分数,%)合金的组织和性能影响。结果表明,添加0.10%～0.5%Sc后,在室温到300℃测试范围内,合金的室温拉伸强度、高温耐热性能及晶界腐蚀性能得到了改善。添加0.3%～0.5%Sc明显细化铸态合金的晶粒,晶粒尺寸从平均300μm降低到60μm。同时,添加0.3%Sc有助于提高铸态合金的室温与高温拉伸强度,改善合金的抗腐蚀性能。含0.3%Sc的Al-5.3Cu-0.8Mg-0.6Ag-0.2Zr合金的力学性能得到提高的原因是由于细晶强化、固溶强化、时效强化、弥散强化及晶界强化共同作用的结果。同时研究也表明,当合金中同时添加0.5%Sc时,铸态合金中形成了粗大的Al3(Sc,Zr)相稀土化合物相,这种化合物相严重降低了合金的拉伸性能与抗腐蚀性能。The Al-Cu-Mg-Ag-Zr alloys with different scandium contents were prepared by ingot metallurgy technology.Effects of scandium addition on the microstructure and properties of Al-5.3Cu-0.8Mg-0.6Ag-0.2Zr（mass fraction,%） alloy were investigated using optical microscope,scanning electron microscopy（SEM） and transmission electron microscopy（TEM）,tensile testing and intercrystalline corrosion testing.The results show that the Sc addition of 0.3%-0.5% refines the grains of the casting alloys and the average grain size decreases from over 300 μm to 60 μm.With increasing Sc content from 0 to 0.3%,the tensile strength increases at all test temperatures up to 300 MPa,and the corrosion resistance is also improved at room temperature.The improvement of mechanical properties in Al-Cu-Mg-Ag-Zr alloy with 0.3% Sc is due to the fine-grained strengthening,solid solution strengthening,precipitation strengthening,dispersion strengthening and grain boundary strengthening.However,the coarsenening Al3（Sc,Zr） compounds in the as-cast alloy with 0.5% Sc decrease the tensile properties and corrosion-resistant performance seriously.

关 键 词：铝合金 钪 显微组织 性能 

分 类 号：TG136.1[一般工业技术—材料科学与工程]