Zr含量对ZL114A合金微观组织与力学性能的影响

摘要

借助OM、SEM、EDS与力学性能测试表征,对比研究了Zr含量对ZL114A合金微观组织与力学性能的影响.结果表明,Zr元素以K2ZrF6形式添加时具有良好的晶粒细化效果与硅相变质作用,当Zr含量达到0.2%时,初生α-Al基体平均尺寸约为65 μm,共晶硅形貌为椭球状,ZL114A合金T6态平均抗拉强度、屈服强度、伸长率与布氏硬度分别为329 MPa、286 MPa、8.2%与HBS116,当Zr含量过高时,易形成较大的块状Al3Zr相,沉淀在坩埚底部,晶粒细化与硅相变质效果随之衰减.%The effect of Zr content on microstructure and mechanical properties of ZL114A alloy was investigated using the OM,SEM,EDS and mechanical properties test.The results show that excellent grain refinement and silicon modification can be attained when Zr element was mixed in the alloy by adding potassium fluorozirconate,the grain size changes to 65 μm and the morphology of eutectic silicon is shown as ellipsoid when the content of Zr is 0.2%,and the average tensile strength,yield strength,elongation and Brinell hardness in T6 state are 329 MPa,286 MPa,8.2% and HBS116 respectively.However,worse effect of grain refinement and silicon modification can be observed with excessive addition of Zr element,due to formation of coarse Al3Zr phase,which precipitates at the bottom of the crucible.