变形Mg-1.5Zn-xCe合金织构及室温成形性能

实验研究了不同Ce元素含量对变形Mg-1.5Zn合金的织构及室温成形性能的影响.结果表明:在相同的热轧和退火工艺处理后,添加不同含量的Ce元素均可以有效弱化镁合金织构强度.Mg-1.5Zn合金中添加质量分数为0.2%的Ce元素后表现出了优异的室温成形性能,织构强度最大值仅为2.20,织构沿着横向分裂,并且基面法向即c轴沿着横向发生约为±35°偏转,室温下轧向方向延伸率达到23.2%,埃里克森杯突值为5.46,平面各项异性系数Δr=0.01;然而,Mg-1.5Zn合金中添加质量分数分别为0.5%和0.9%的Ce元素后,织构强度增加,埃里克森杯突值减小,由于在合金中生成了粗大的第二相粒子,使得Mg-1.5Zn-xCe合金的室温成形性能变低. 

Texture and room-temperature formability of rolled Mg-1.5Zn-xCe alloys

The texture and room-temperature formability of rolled Mg-1.5Zn alloys containing different contents of Ce were inves-tigated by experiment, it is indicated that during the same hot rolling and annealing processes, Ce addition can effectively modify and weaken the texture. When 0.2wt% Ce is added, the Mg-1.5Zn alloy has excellent room-temperature formability, and its maximum texture intensity is only 2.20. This alloy exhibits the transverse direction split texture, whose basal pole is tilted by about ±35° from the normal direction toward the transverse direction. At room temperature, the Erichsen value reaches 5.46, and the ultimate elonga-tion in the rolling direction is 23.2% with a low planar anisotropy value of 0.01. However, 0.5% and 0.9% Ce additions promote the formation of huge secondary phase particles, resulting in an increase in the intensity of the basal texture, a decrease in the Erichsen value, and deterioration in the room-temperature stretch formability.