TC4-DT钛合金基于最大m值的超塑变形

Study on superplastic deformation based on maximum mvalue method of TC4-DT titanium alloy

采用最大m值法,在温度分别为850℃、870℃、900℃下,对改锻前及改锻后的TC4-DT钛合金棒材进行超塑性拉伸实验。实验结果表明,根据最大m值法拉伸试样TC4-DT在870℃的变形温度下,延伸率达到了最大值1240%,表明该类型TC4-DT钛合金的最佳超塑性变形温度在870℃左右;并且改锻后较细晶粒尺寸的TC4-DT棒材的超塑性明显高于改锻前的较粗晶粒组织,延伸率平均提高了一倍;分析显微组织可知,在超塑性拉伸变形中发生了动态再结晶。

Superplastic deformation characteristics of TC4-DT titanium alloy were investigated within temperature of 850℃- 900℃ by the method of maximum rn value method. Experimental results show that, according to the tensile test results based on maximum rn value method of TCA-DT titanium alloy under the deformation temperature of 870℃, the maximum elongation reached 1240%, shows that the best deformation temperature of this type TCA-DT titanium alloy is at about 870℃. The superplasticity of after-forging TC4-DT bar is better than the original bar, and the elongation increased on average of one times. Anal ysis the microstructure shows that dynamic recrystallization occured in the superplastic tensile deformation.