摘要
为提高Sc在Al-Mg-Sc-Zr合金中的利用率,通过金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)以及拉伸试验等手段,研究了挤压铸造对Al-5.36Mg-0.40Mn-0.16Sc-0.14Zr合金沉淀相析出行为及相关力学性能的影响。结果表明,与金属型铸锭相比,挤压铸锭的晶界析出相分布更加弥散,初生微米级Al3(Sc,Zr)相的长大受到抑制,晶粒尺寸略有长大。不经过热处理,挤压铸锭的抗拉强度与伸长率都明显高于金属型铸锭,而屈服强度相当;经过350℃×12h时效处理后,挤压铸锭与金属型铸锭的基体中均析出纳米级的二次Al3(Sc,Zr)相,但挤压铸锭基体中析出的纳米级Al3(Sc,Zr)相更多,沉淀强化作用更加明显,其屈服强度比金属型铸锭高出约26MPa。
To improve the utilization of Sc in the Al-Mg-Sc-Zr alloy,effects of squeeze casting on precipitation behaviors and mechanical properties of Al-5.36Mg-0.40Mn-0.16Sc-0.14Zr（mass fraction,%）alloy were investigated by optical microscopy（OM）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）and tensile tests.The results show that precipitates on grain boundaries are more dispersed in the squeeze casting than in the permanent mould casting.Few primary Al3（Sc,Zr） microparticles can be observed in the squeeze casting,and the average grain size is grown slightly.Although the yield strength of the samples in two casting methods is nearly the same,the tensile strength and elongation of the samples in the squeeze casting are higher than those in the permanent mould casting.After 350℃/12hannealing,the Al3（Sc,Zr）nanoparticles are precipitated from the matrix both in squeezing casting and in permanent mould casting,however,there are more Al3（Sc,Zr）nanoparticles precipitated in the squeezing casting,showing a stronger precipitation strengthen effect,where the yield strength of the alloy is 25MPa higher than that in the permanent mould casting.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2014年第1期1-6,共6页
Special Casting & Nonferrous Alloys
