The single-phase Mg-4Li-0.5Ca alloy was rolled at three different temperatures(250,300 and 350℃)and followed by annealing at 200°C for 10 min.To evaluate the mechanical properties,the tensile test was conducted ...The single-phase Mg-4Li-0.5Ca alloy was rolled at three different temperatures(250,300 and 350℃)and followed by annealing at 200°C for 10 min.To evaluate the mechanical properties,the tensile test was conducted at a constant strain rate of 10^(-3)s^(-1).Factors influencing the tensile strength and strain hardening properties were assessed by microscopy,XRD and EBSD analysis.Besides,Kocks-Mecking plots(K-M)were used to determine the different stages of strain hardening exhibited by the variously processed Mg-4Li-0.5Ca alloy test specimens.The ultimate tensile strength has decreased as hot-rolling temperature in creases with increased ductility.The strain hardening properties such as hardening capacity(Hc),strain hardening exponent(n)are increased significantly with an increase in hot rolling temperature and subsequent annealing.展开更多
In order to study the corrosion resistance of extruded magnesium alloys,the Mg-4Zn-2Gd-0.5Ca alloy was extruded at the speed of 0.01-0.1 mm/s with the temperature of 280-360℃in present study.Hot extrusion results sho...In order to study the corrosion resistance of extruded magnesium alloys,the Mg-4Zn-2Gd-0.5Ca alloy was extruded at the speed of 0.01-0.1 mm/s with the temperature of 280-360℃in present study.Hot extrusion results show that the volume fraction of precipitates(Vpre),VDRX(the dynamic recrystallization rate) and the average size of DRXed grain(dDRX) decrease with the decrease in extrusion speed,and the corrosion rate of the alloy also shows a downward trend.On the contrary,the values of Vpre,VDRX and dDRX increase with the increase in extrusion temperature,and the corrosion resistance of Mg-4Zn-2Gd-0.5Ca alloy decreases.When the extrusion speed is 0.01 mm/s and the extrusion temperature is 280℃,the alloy has the best corrosion resistance.The corrosion of extruded Mg-4Zn-2Gd-0.5Ca alloy occurs preferentially on the magnesium matrix around W and I phases in the DRXed zone.With the further corrosion,the corrosion continues to spread along the phase,and the corrosion area gradually increases.Galvanic corrosion plays a leading role in the corrosion process.Moreover,there are a large number of basal plane textures in the unDRXed region,which is conducive to improving the corrosion resistance of magnesium alloys.In addition,the decrease in grain size also makes the corrosion of magnesium alloy more uniform.展开更多
文摘The single-phase Mg-4Li-0.5Ca alloy was rolled at three different temperatures(250,300 and 350℃)and followed by annealing at 200°C for 10 min.To evaluate the mechanical properties,the tensile test was conducted at a constant strain rate of 10^(-3)s^(-1).Factors influencing the tensile strength and strain hardening properties were assessed by microscopy,XRD and EBSD analysis.Besides,Kocks-Mecking plots(K-M)were used to determine the different stages of strain hardening exhibited by the variously processed Mg-4Li-0.5Ca alloy test specimens.The ultimate tensile strength has decreased as hot-rolling temperature in creases with increased ductility.The strain hardening properties such as hardening capacity(Hc),strain hardening exponent(n)are increased significantly with an increase in hot rolling temperature and subsequent annealing.
基金financially supported by the National Natural Science Foundation of China(Nos.51771128,51771129 and 51201112)the Projects of International Cooperation in Shanxi(No.201703D421039)the Natural Science Foundation of Shanxi(No.201601D011034).
文摘In order to study the corrosion resistance of extruded magnesium alloys,the Mg-4Zn-2Gd-0.5Ca alloy was extruded at the speed of 0.01-0.1 mm/s with the temperature of 280-360℃in present study.Hot extrusion results show that the volume fraction of precipitates(Vpre),VDRX(the dynamic recrystallization rate) and the average size of DRXed grain(dDRX) decrease with the decrease in extrusion speed,and the corrosion rate of the alloy also shows a downward trend.On the contrary,the values of Vpre,VDRX and dDRX increase with the increase in extrusion temperature,and the corrosion resistance of Mg-4Zn-2Gd-0.5Ca alloy decreases.When the extrusion speed is 0.01 mm/s and the extrusion temperature is 280℃,the alloy has the best corrosion resistance.The corrosion of extruded Mg-4Zn-2Gd-0.5Ca alloy occurs preferentially on the magnesium matrix around W and I phases in the DRXed zone.With the further corrosion,the corrosion continues to spread along the phase,and the corrosion area gradually increases.Galvanic corrosion plays a leading role in the corrosion process.Moreover,there are a large number of basal plane textures in the unDRXed region,which is conducive to improving the corrosion resistance of magnesium alloys.In addition,the decrease in grain size also makes the corrosion of magnesium alloy more uniform.
