T6热处理对消失模铸造AZ91D与AZ91D-1.5%Y镁合金组织与性能的影响

Effect of T6 Heat Treatment on Microstructure and Properties of AZ91D and AZ91D-1.5%Y Magnesium Alloys in Lost Foam Casting

以消失模铸造AZ91D和AZ91D-1.5%Y镁合金作为研究对象,利用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线能谱仪(EDS)、及金属拉伸和硬度试验等系统研究了消失模铸造AZ91D和AZ91D-1.5%Y镁合金在T6热处理过程中β-Mg17Al12相的溶解与析出对组织及力学性能的影响。结果表明,T6(420℃固溶20 h,250℃时效)处理工艺中,随时效时间的延长,AZ91D与AZ91D-1.5%Y镁合金的硬度和抗拉强度不断提高,当时效时间为15 h时,硬度和抗拉强度达到最大值,AZ91D-1.5%Y镁合金固溶处理后硬度及抗拉强度均高于AZ91D镁合金。

In lost foam casting AZ91 D magnesium alloy AZ91D-1.5% Y and as the research object, using the optical microscope(OM), scanning electron microscope(SEM), X-ray diffraction(XRD), X-ray spectrometer(EDS), and metal tensile and hardness test system to study the lost foam casting AZ91 D magnesium alloy AZ91D-1.5%Y and β-Mg17Al12 phase in the process of T6 heat treatment of dissolution and precipitation of the influence of the structure and mechanical properties. The results show that the T6(250 ℃ 420 ℃ solution 20 h, aging) process, along with the aging time, the hardness and tensile strength of AZ91 D magnesium alloy AZ91D-1.5%Y will be increasing;When the aging time is 15 h,the hardness and tensile strength reach the maximum, and the hardness and tensile strength of AZ91D-1.5%Y magnesium alloy after solid solution treatment are higher than AZ91 D magnesium alloy.