医用Mg-Zn-Y-Nd合金微细管材的制备及组织性能研究

Preparation,Microstructure and Properties of Medical Mg-Zn-Y-Nd Alloy Micro-tubes

通过二次热挤压、冷拉拔以及退火等方法制备外径2.46 mm、壁厚0.14 mm的Mg-Zn-Y-Nd合金微细管材。采用OM、SEM、EBSD以及拉伸试验对微细管材的显微组织、尺寸误差、表面粗糙度以及力学性能进行分析。结果表明:微细管材的外径误差、内径误差以及壁厚误差分别为0.51%、0.32%、3.35%。冷拉拔微细管材的屈服强度为342 MPa,抗拉强度为350 MPa,延伸率为0.5%。经退火处理后,微细管材发生静态再结晶,造成晶粒细化、织构弱化以及第二相颗粒的弥散分布,其综合力学性能得到显著改善。退火态微细管材的断口表现出典型的韧性断裂特征,其屈服强度、抗拉强度以及延伸率分别为246 MPa、306 MPa、18.0%。

In this study,Mg-Zn-Y-Nd alloy micro-tubes with an outer diameter of 2.46 mm and a wall thickness of 0.14 mm were prepared by secondary hot extrusion,cold drawing and annealing.The microstructure,dimension error,surface roughness and mechanical properties of the micro-tubes were analyzed by OM,SEM,EBSD and tensile test.The results showed that:the outer diameter error,inner diameter error and wall thickness error of the micro-tubes were 0.51%,0.32%and 3.35%,respectively.The yield strength,tensile strength and elongation of the drawn micro-tubes were 342 MPa,350 MPa and 0.5%.After annealing,the micro-tubes under went static recrystallization,which resulted in grain refinement,texture weaken and dispersion of the secondphase particles.The mechanical properties of the annealed micro-tubes were significantly improved.The fractures of the annealed micro-tubes exhibited typical ductile fracture characteristics,and its yield strength,tensile strength and elongation were 246 MPa,306 MPa and 18.0%,respectively.