含Zr多晶Ni_3Al合金在不同热处理温度下的组织与性能

MICROSTRUCTURE AND TENSILE PROPERTIES OF Zr-DOPED Ni3Al ALLOYS AT DIFFERENT HEAT-TREATMENT TEMPERATURES

研究了冷轧多晶Ni3Al-(0.2％,0.6％,1.0％,1.5％)Zr(原子分数)合金在不同热处理温度(800—1100℃)下的显微组织和力学性能.结果表明,适当的热处理温度,可使无硼Ni3Al-Zr多晶合金获得优良的室温拉伸强度和塑性.随着热处理温度的升高,不同Zr含量Ni3Al合金的再结晶体积分数增加,再结晶晶粒尺寸增大,室温拉伸强度下降.随着合金中Zr含量的增加,再结晶温度降低,再结晶晶粒尺寸减小.不同Zr含量Ni3Al合金的拉伸塑性明显依赖于热处理温度.对于低Zr(0.2％)合金,在1000℃热处理后,拉伸塑性最佳;对于中Zr(0.6％)合金,在850℃热处理后,拉伸塑性达到最大值;对于高Zr(≥1.0％)合金,拉伸塑性峰值出现在900℃热处理下,当热处理温度超过900℃,拉伸塑性显著降低.

The microstructure and tensile properties of Zr doped cold-rolled polycrystalline Ni3Al alloys at room temperature were influenced by heat-treatment temperature. The results show that the proper heat-treatment temperature could improve both the ductility and strength of Zr-doped Ni3Al alloys. The volume fraction of recrystallized zone and the recrystallized grain size increase with raising of heat-treatment temperature, so the strength decreases. The recrystallized temperature decreases with the increase of Zr content, while the size of grain reduces. The ductility obviously depends on the heat-treatment temperature. The ductility is the maxium for low Zr content (0.2%, atomic fraction) alloys when the heat-treatment temperature is 1000degreesC, it is 850degreesC for the middle Zr content (0.6%) alloys. But for the alloys with high Zr content ( greater than or equal to1.0%), the highest ductility arises at 900degreesC, when the temperature is higher than 900degreesC the ductility evidently falls down.