摘要
采用密闭半固态搅拌铸造工艺结合热挤压制备Ni颗粒增强AZ61复合材料板材,Ni颗粒含量(质量分数,下同)分别为3%,6%和9%,研究Ni_p/AZ61复合材料的微观组织、力学性能以及强化机制。结果表明:Ni_p/AZ61复合材料的增强相主要为细小的Mg_2Ni相和大块Al Ni相,尺寸分别为2～4μm和10～20μm。Mg_2Ni和AlNi能有效细化晶粒、促进再结晶,与镁基体结合良好。颗粒周围存在位错塞积,基体存在孪晶。Mg2Ni和Al Ni相都能有效提高材料的硬度、弹性模量和抗拉强度,但伸长率降低。9%Ni_p/AZ61复合材料的抗拉强度达到286.5±1.2 MPa,伸长率为4.3%±0.9%。Ni_p/AZ61复合材料的强化机制为细晶强化、Orowan强化以及载荷传递效应。
Ni particle reinforced AZ61composites with the Ni mass fraction of3%,6%and9%respectively were prepared by closed semi-solid stirring casting and hot extrusion,and the microstructure,mechanical properties and strengthening mechanism were studied.The results show that the reinforcement phases of Nip/AZ61composite are the fine Mg2Ni phase and large AlNi phase,and their sizes are2?4μm and10?20μm,respectively.The Mg2Ni and AlNi phases can effectively refine the grains,promote recrystallization,and have a good bonding with the magnesium matrix.Dislocation pile-up are present around the particles and twins are present in the matrix.Both Mg2Ni and AlNi phases can effectively improve the hardness,elastic moduous and tensile strength,but the elongation decreases.9%Nip/AZ61has tensile strength286.5±1.2MPa and elongation of and4.3%±0.9%.The strengthening mechanism of Nip/AZ61are fine grain strengthening,Orowan strengthening and load transfer effect.
作者
冯艳
陈超
王日初
王小峰
FENG Yan;CHEN Chao;WANG Richu;WANG Xiaofeng(Key Laboratory of Hunan Province for Electronic Packaging and Advanced Functional Materials,Central South University, Changsha 410083, China;College of Materials Science and Engineering, Central South University, Changsha 410083, China)
出处
《粉末冶金材料科学与工程》
EI
北大核心
2018年第6期562-568,共7页
Materials Science and Engineering of Powder Metallurgy
基金
湖南省自然科学基金面上项目(2016JJ2147)
湖南省创新人才计划资助项目(2015JC3004)
