| 唐昌平,李国栋,李志云,孙玹琪.铸造Mg-Gd-Y-Nd-Zr合金在时效过程中的组织与性能演变[J].材料导报,2018,32(4):574-578 |
| 铸造Mg-Gd-Y-Nd-Zr合金在时效过程中的组织与性能演变 |
| Microstructure and Mechanical Property Evolution of Mg-Gd-Y-Nd-Zr Casting Alloy During Aging Treatment |
| |
| DOI：10.11896/j.issn.1005-023X.2018.04.013 |
| 中文关键词: Mg-Gd-Y合金 时效处理 微观组织 力学性能 断口分析 |
| 英文关键词: Mg-Gd-Y alloy, aging treatment, microstructure, mechanical property, fracture analysis |
| 基金项目:基金项目:国家自然科学基金(51605159)；湖南省自然科学基金(2016JJ5042) |
|
| 摘要点击次数: 2100 |
| 全文下载次数: 944 |
| 中文摘要: |
| 采用金相观察、硬度测试、单轴拉伸、扫描电镜观察、能谱分析、透射电镜观察等手段,研究了铸造Mg-Gd-Y-Nd-Zr合金在时效过程中的组织与性能演变。结果表明,经固溶处理后,合金具有较强的塑性变形能力,延伸率可达10%以上,但强度较低。随时效程度增加,合金强度升高塑性降低,经225 ℃/3 h时效处理后,合金为欠时效状态,与基体共格的β″相是主要的强化相,断口以解理面、韧窝、撕裂棱和晶界为主要特征。经峰值时效处理后,与基体呈半共格关系的β′相是主要的强化相,合金抗拉强度超过300 MPa,但塑性急剧降低,断口以解理面、撕裂棱和晶界为主要特征,与欠时效样品相比,解理面所占比例明显增加,且解理面及晶界光滑。进入过时效状态后,合金的强度降低,但延伸率有所提升,断口以晶界和解理面为主要特征。 |
| 英文摘要: |
| Microstructure and mechanical property evolution of Mg-Gd-Y-Nd-Zr casting alloy during aging treatment were investigated by means of optical microscopy (OM), hardness testing, uniaxial tensile testing, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicated that the alloy exhibited good ductility and low strength after solution treatment, and the elongation exceeded 10%. As the aging time prolonged, the strength increased while the ductility decreased. The sample was in under-aged state when treated at 225 ℃ for 3 h, and β″was the main strengthening phase, which was coherent with the matrix. The fracture surface of the sample featured cleavage planes, dimples, tea-ring ridges and grain boundaries. In the peak-aged state, the strengthening phase was β′, which is semi-coherent with the matrix. The ultimate tensile strength of the peak-aged sample exceeded 300 MPa, while the ductility decreased sharply. The fracture surface of the sample featured cleavage planes, tearing ridges and grain boundaries. The proportion of cleavage planes was obviously higher than that in under-aged sample, and the cleavage plane and the grain boundary were smooth. The strength increased but the ductility decreased when the sample was over-aged. Grain boundaries and cleavage planes were the main characterization of the fracture surface. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
