【摘要】 基于对高强镁合金的迫切需求,选用Sm作为合金化元素添加到ZK30镁合金中。采用真空感应熔炼炉制备ZK30-x Sm镁合金（x=0%,1%,2%,3%,4%,质量分数）,研究了不同含量的Sm对铸态ZK30镁合金微观组织和力学性能的影响。通过OM,SEM,EDS,XRD观察和分析了合金的微观形貌和组织成分,并对材料进行了拉伸试验和硬度测试。结果表明:加Sm镁合金主要由α-Mg基体和Mg₄₁Sm₅相组成,并且合金组织由树枝晶转变为细小的等轴晶;合金的抗拉强度σ_b,屈服强度σ_{0. 2}和伸长率δ随着Sm含量的增加先升高后降低,当Sm含量为1%时,σ_b,σ_0.2和δ均达到最大值,分别为250. 4,109. 0 MPa和14. 4%;合金的硬度也在Sm含量为1%时,达到最大值59. 85 kgf·mm^-2。但过量的Sm恶化组织,降低了性能。添加元素Sm后合金性能的提高主要归因于细晶强化、固溶强化和析出强化的共同作用。更多还原

【Abstract】 Based on the urgent demand of high strength magnesium alloy,Sm was added as alloying element to ZK30 magnesium alloy. The ZK30-x Sm magnesium alloys（ x = 0%,1%,2%,3%,4%,mass fraction） were prepared by using a vacuum induction melting furnace. The effect of different content of Sm on the microstructure and properties of as-cast ZK30 magnesium alloy was studied. The microstructure of the alloys was observed and analyzed by optical microscopy（ OM）,scanning electron microscopy（ SEM）,energy dispersive spectroscopy（ EDS）and X-ray diffractometer（ XRD）. The tensile test and hardness test were also carried out. Results showed that the main phases in Mg-3 Zn-xSm-0. 5 Zr alloys included matrix α-Mg and Mg₄₁Sm₅ phase,and the microstructure changed from dendrites to fine equiaxed grains. The ultimate tensile strength σ_b,yield strength σ_{0. 2} and elongationδ of the alloys increased first and then decreased with the increase of Sm content. When the Sm content was 1%,σb,σ_{0. 2},and δ of the alloys reached the maximum of 250. 4,109. 0 MPa and 14. 4%,respectively. The hardness of the ZK30-1 Sm alloy reached a maximum 59. 85 kgf·mm^-2. But excessive Sm damaged the microstructure and properties. Due to the addition of Sm resulting to grain refinement strengthening,solid solution strengthening and precipitation strengthening,the properties of ZK30 alloys was improved obviously.更多还原