【作者】 马志新； 李德富； 李彦利；

【Author】 Ma Zhixin;Li Defu;Li Yanli;Research Center of Process Engineer for Non-ferrous Metals,Beijing General Research Institute for Non-ferrous Metals;

【机构】 北京有色金属研究总院有色金属加工工程研究中心；

【摘要】 对Mg-Y-Nd-Zr镁合金铸锭分别进行挤压和锻压变形加工,然后对变形加工件进行固溶、时效处理。采用金相显微镜、扫描电镜及能谱仪分析研究了该合金的组织演化过程。分别测试了铸造、挤压、锻压和热处理等不同状态下合金试样的室温和250℃力学性能。结果表明,该合金在350～400℃内进行挤压,组织发生完全动态再结晶,可以获得较好的力学性能;挤压后进行锻压变形,试样的室温抗拉强度和屈服强度分别比挤压状态提高13.5%和15%,伸长率下降33.3%;250℃的抗拉强度和屈服强度比挤压状态分别提高15%和41.4%。试样经过T6处理后,晶界附近析出相尺寸细小、分布均匀,室温抗拉强度和屈服强度分别达到365 MPa和335 MPa。固溶强化和析出强化是导致T6状态试样拉伸强度提高的两个主要因素。更多还原

【Abstract】 The processes of extruding and forging were applied on the Mg-Y-Nd-Zr alloy separately,then the deformed specimens were treated on solid solution and aging.The structure evolution of this alloy was analyzed by means of optical microscopy,scanning electron microscopy and energy disperse spectroscopy.The tensile properties of as-cast,as-extruded,as-forged and heat treated alloy specimens were tested at room temperature and 250℃.The study shows that complete dynamic recrystallization occurs when extruded at the temperature of 350～400℃,and better mechanical performance can be achieved.Compared with the extruded specimens,the tensile strength and yield strength of forged specimens at room temperature were increased 13.5% and 15 % but the elongation was decreased 33.3%,and both of strength at 250℃ were increased 15% and 41.4%.Treated in T6 condition after forged,the size of precipitated phases near grain boundaries of specimens become finer and more homogeneous,and the tensile strength and yield strength at room temperature were arrived to 365 MPa and 335 MPa.The solution strengthening and precipitation strengthening are the two main reasons for the elevation of the tensile properties of specimens treated in T6 condition.更多还原