Gd含量及热处理对Mg-Gd-Zr合金显微组织和力学性能的影响
发布时间：2018-12-14 16:27
【摘要】：采用金相光学显微镜(OM),扫描电镜(SEM),能谱仪(EDS)以及X射线衍射(XRD)等手段,研究了不同Gd含量(1%,2%,3%,原子分数)与不同热处理状态(铸态,固溶态,时效态)对Mg-Gd-Zr合金显微组织和力学性能的影响。结果表明:铸态组织中,Gd元素富集在晶界,随Gd含量增加,共晶组织增多,并逐渐呈网状分布,合金的晶粒逐渐变小。经过535℃,24 h固溶处理,共晶组织分解,残留相主要为富Gd的方块相,数量随Gd含量升高增加,晶粒尺寸比铸态组织长大。再经过220℃,24 h时效处理,合金中析出第二相,晶粒尺寸与固溶态差别不大。合金的抗拉强度,屈服强度和硬度(R_m,R_(p0.2),HB)随Gd含量增加呈上升趋势,断后伸长率随Gd含量升高呈降低趋势。经过535℃,24 h固溶处理,消除了铸造应力,且使合金晶粒长大,降低了合金强度。时效处理后,合金中析出第二相,合金强度升高,且Gd含量越高析出第二相越多,强化效果越明显。拉伸断裂后,铸态合金呈解理断裂,固溶态合金呈穿晶断裂,时效态合金呈沿晶断裂。
[Abstract]:By means of optical microscope (OM), scanning electron microscope (OM), (SEM), energy spectrometer (EDS) and X-ray diffraction (XRD), the different contents of Gd (1 / 2 / 3, atomic fraction) and different heat treatment states (as cast) were studied. The effect of solution state and aging state on the microstructure and mechanical properties of Mg-Gd-Zr alloy. The results show that the Gd element is enriched at the grain boundary in the as-cast structure. With the increase of Gd content, the eutectic structure increases and gradually distributes as a network, and the grain size of the alloy becomes smaller. After solution treatment at 535 鈩，
本文编号：2378943
[Abstract]:By means of optical microscope (OM), scanning electron microscope (OM), (SEM), energy spectrometer (EDS) and X-ray diffraction (XRD), the different contents of Gd (1 / 2 / 3, atomic fraction) and different heat treatment states (as cast) were studied. The effect of solution state and aging state on the microstructure and mechanical properties of Mg-Gd-Zr alloy. The results show that the Gd element is enriched at the grain boundary in the as-cast structure. With the increase of Gd content, the eutectic structure increases and gradually distributes as a network, and the grain size of the alloy becomes smaller. After solution treatment at 535 鈩，
本文编号：2378943
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