Zhao Huichao, Shen Junqi, Hu Shengsun, Zhen Yahui, Chen Yang
Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin 300354, China.
School of Materials Science and Engineering, Tianjin University, Tianjin 300354, China.
Materials (Basel). 2024 May 15;17(10):2348. doi: 10.3390/ma17102348.
Friction stir processing (FSP) is a solid-state treating method to enhance the mechanical properties of materials by altering their microstructure. In this study, FSP was applied to the AZ91 magnesium alloy cladding layer prepared using cold metal transition (CMT) technology, and the purpose was to investigate the effect of the traverse speed of the H13 steel stirring head under a constant rotation speed on the microstructure and mechanical properties of the cladding layer. The results demonstrated that FSP could effectively decrease the grain size of the cladding layer and lead to the dispersion and dissolution of the coarse β-MgAl second phase into the α-Mg matrix. The mechanical characteristics of the processed cladding layer were significantly enhanced compared to the unprocessed cladding layer due to the grain refinement and second-phase strengthening induced by FSP. When the stirring head rotation speed was set at 300 r/min, the average microhardness and tensile properties of the specimens showed a tendency of initially increasing and then dropping as the traverse speed increased. The cladding layer, obtained at a traverse speed of 60 mm/min, displayed optimal mechanical properties with an average microhardness, tensile strength, and elongation of 85.6 HV, 278.5 MPa, and 13.4%, respectively.
搅拌摩擦加工（FSP）是一种固态处理方法，通过改变材料的微观结构来提高其力学性能。在本研究中，将FSP应用于采用冷金属过渡（CMT）技术制备的AZ91镁合金熔覆层，目的是研究在恒定转速下H13钢搅拌头的横移速度对熔覆层微观结构和力学性能的影响。结果表明，FSP能有效减小熔覆层的晶粒尺寸，并使粗大的β-MgAl第二相弥散并溶解到α-Mg基体中。由于FSP引起的晶粒细化和第二相强化，加工后的熔覆层的力学性能相比未加工的熔覆层有显著提高。当搅拌头转速设定为300 r/min时，随着横移速度的增加，试样的平均显微硬度和拉伸性能呈现出先增加后下降的趋势。在横移速度为60 mm/min时获得的熔覆层表现出最佳力学性能，平均显微硬度、抗拉强度和伸长率分别为85.6 HV、278.5 MPa和13.4%。
