Effect of microstructure on the impact toughness of magnesium alloys
Microstructures of as-cast and extruded ZK60-xRE (RE=Dy,Ho and Gd,x=0~5) alloys were investigated by optical microscope,scanning electron microscope,transmission electron microscope,X-ray diffraction and differential scanning calorimetry.Meanwhile,the impact toughness at ambient temperature was tested and then the relationship was discussed.The results show that the impact toughness value αnK increases from 9~17 J/cm2 for as-cast state to 26~54 J/cm2 for extruded state.With increasing the value of αnK,fracture macro-morphology changes from a rough plane via multi-plane with step to V-type plane with angle of approximately 120°,and from single radiation zone to two zones of fiber and shear lip,respectively.Fracture micro-morphology does from the brittle fracture to the ductile fracture.V-type impact fracture and micro-morphology are formed under the interaction of tensile and tear stresses.Fine grain and few fine dispersed second phase can enhance the impact toughness of magnesium alloys effectively.
Magnesium alloys impact toughness microstructure grain size second phase
Huang Zhenghua Qi Wenjun Xu Jing
Guangzhou Research Institute of Non-ferrous Metals, Guangzhou 510650, China
国际会议
上海
英文
19-19
2012-10-19（万方平台首次上网日期，不代表论文的发表时间）