摘要
低Y、Ni含量的LPSO结构增强镁合金具有低成本、优异力学性能的特点。为进一步提升其综合力学性能,掺杂Al元素及熔体超声振动处理是可行的途径。通过扫描电子显微镜、能谱分析、透射电子显微镜、X射线衍射和纳米压痕测试研究掺杂Al元素后低Y、Ni含量的Mg_(98)Y_(1.0)Ni_(0.5)Al_(0.5)合金的显微组织,对比超声振动对显微组织与力学性能的影响。掺杂Al后LPSO结构的含量降低,且在块状LPSO结构相邻处析出圆整的Al_(2)NiY相。Al_(2)NiY相与LPSO结构和Mg基体在界面处均不共格。通过对熔体施加超声振动处理后,Al_(2)NiY相被有效细化为短片状,并均匀分布在基体中,阻碍微裂纹的产生和扩展,从而提高Mg98Ni0.5Y1.0Al0.5合金的力学性能。与未经超声处理Mg_(98)Ni_(0.5)Y_(1.0)Al_(0.5)合金相比,其极限抗拉强度和伸长率提升至187 MPa和7.9%,分别增长21.4%和105.7%。
The LPSO structure reinforced magnesium alloy with low Y and Ni contents can achieve the best balance between performance and cost.To further improve the comprehensive mechanical properties,doping with Al element and ultrasonic vibration treatment are feasible approaches.The microstructure of low Y and Ni containing Mg_(98)Y_(1.0)Ni_(0.5)Al_(0.5)alloy with Al addition and the effect of ultrasonic vibration on the microstructure and mechanical properties were studied by SEM-EDS,TEM,XRD and nano-indentation.Doping Al into the alloy decreases the amount of LPSO structure,and Al_(2)NiY phases with radial morphology precipitate near the block LPSO structure.The Al_(2)NiY phase is non-coherent with LPSO structure and Mg matrix at the phase interfaces.The Al_(2)NiY phase can be effectively modified into short flakes and distributed uniformly in the matrix with ultrasonic vibration treatment.The mechanical properties of Mg_(98)Y_(1.0)Ni_(0.5)Al_(0.5)alloy are improved by reducing the generation of microcracks and preventing their propagation.Compared with Mg98Ni0.5Y1.0Al0.5alloy without ultrasonic vibration treatment,the ultimate tensile strength and elongation of the alloy with ultrasonic vibration treatment are improved to 187 MPa and 7.9%,with increments of 21.4%and 105.7%,respectively.
作者
吕书林
赵第甲
计效园
郭威
Shu-lin LÜ;Di-jia ZHAO;Xiao-yuan JI;Wei GUO(State Key Lab of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China;Research Institute of Huazhong University of Science and Technology in Shenzhen,Shenzhen 518057,China)
基金
the financial supports from the National Natural Science Foundation of China(Nos.52175321,52101138)
Start-up Fund from Huazhong University of Science and Technology,China(Nos.3004110125,3004110142)
State Key Lab of Advanced Metals and Materials,China(No.2020-Z01)
State Key Laboratory for Mechanical Behavior of Materials,China(No.20202205)
State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,China(No.32015001)
Guangdong Basic and Applied Basic Research Foundation,China(No.2020A1515110531)
Natural Science Foundation of Hubei Province,China(No.2020CFB259)。
