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％，延伸率下降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和335MPa。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。
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 aUoy was analyzed by means of optical microscopy, scanning electron microscopy and energy disperse spectroscopy. The tensile properties of as-cast, as-extruded, asforged 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 mechanieal performance can be achieved. Compared with the extruded specimens, the tensile strength and yield strength of forged specimens at room temperature are increased by 13.5% and 15% but the elongation is decreased by 33.3 %, and both of the strength at 250℃ is increased by 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 reach to 365 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.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2006年第6期719-723,共5页
Chinese Journal of Rare Metals
基金
"十五"国家科技攻关资助项目(200420ZD-1)
关键词
稀土镁合金
塑性变形
显微结构
力学性能
Mg-RE alloy
plastic deformation
microstructure
tensile properties
