【摘要】 通过显微组织观察和高温力学性能测,试研究了Mn含量对近共晶Al-12%Si-4%Cu-x%Mn合金组织与耐热性的影响。结果表明,随着Mn含量的增加,铝硅铜锰合金铸态组织中的Al15Mn3Si2相数量不断增多,且初生Al15Mn3Si2相的形态逐渐从小的块状及不发达的树枝状,转变为发达的树枝状和细杆状。同时发现,添加元素Mn的S2（0.8%Mn）、S3（1.2%Mn）、S4（1.6%Mn）合金室温和高温抗拉强度均高于S1合金,说明在Al-12%Si-4%Cu合金中引入的富锰相Al₁₅Mn₃Si₂是有利于改善合金耐热性的,并且随着富锰相数量的增加,合金的高温抗拉强度不断增加。但S5（2.0%Mn）合金中的初生Al15Mn3Si2相大部分呈现发达的树枝状和细杆状,脆性很大,耐热性能反而不如S1合金的。更多还原

【Abstract】 Effect of Mn content on the microstructure and heat-resistance of near eutectic Al-12%Si-4%Cu-x%Mn alloys was investigated by microstructure observation and high temperature tensile test.The results show that with the increasing of Mn content,the amount of Al₁₅Mn₃Si₂ phase in the as-cast microstructure,and the morphology of the primary Al₁₅Mn₃Si₂ phase are changed from small block or undeveloped dendrite to developed dendrite or slender rod.And it is found the alloys with Mn addition,S2（0.8%Mn）,S3（1.2%Mn） and S4（1.6%Mn） have more superior high temperature strength than the base alloy S1 without Mn addition,indicating that inducing Al₁₅Mn₃Si₂ phase in Al-Si-Cu base alloy is in favor of the considerable improvement of the high temperature strength.However,S5（2.0% Mn） alloy has a lower high temperature strength than that of S1 alloy due to the developed dendritic or slender rod-like primary Al₁₅Mn₃Si₂ phase has high brittleness.更多还原