基于最大m值法的Ti-23Al-17Nb板材各向异性的超塑性研究  

Anisotropic superplasticity research of Ti-23Al-17Nb alloy based on maximum m value method

作　　者：付明杰[1,2,3] 许慧元[1,2,3] 韩秀全[1,2,3] 王高潮[4] 

机构地区：[1]北京航空制造工程研究所,北京100024 [2]塑性成形技术航空科技重点实验室,北京100024 [3]数字化塑性成形技术与装备北京市重点实验室,北京100024 [4]南昌航空大学航空制造工程学院,南昌330063

出　　处：《中国科学：技术科学》2016年第8期844-850,共7页Scientia Sinica(Technologica)

基　　金：航空科学基金(编号:2015ZE25017)资助项目

摘　　要：最大m值法是获得高超塑延伸率的有效方法之一.本文采用最大m值法对Ti-23Al-17Nb（at.%）合金在温度为940~1000℃、不同方向的超塑拉伸变形行为进行了研究.结果表明：在垂直轧制方向、1000℃条件下进行超塑拉伸,获得的最高延伸率为2507.4%,是至今该类Ti3Al基合金所报道的文献中的最高值.随着变形温度和变形量的增加,原始长条α_2晶粒重复经历拉长、断裂和球化的过程,这是获得高延伸率的原因之一,也是各向异性始终存在的原因.在一定变形条件下,α_2晶粒尺寸和体积分数较大时更有利于Ti3Al基合金的超塑性.1000℃变形时大应变会诱发O相析出,增加了合金抵抗颈缩的能力,从而获得更高的延伸率.The maximum m value method is one of effective method to obtain better superplastic elongation of materials. The different deformation direction superplasticity of Ti-23Al-17Nb（at.%） alloy sheet at temperature of 940-1000℃α were studied in this paper. The results showed the maximum superplastic elongation of 2507.4% is obtained at 1000℃ and T deformation direction, this was the best result of ever been reported on Ti3AI based alloy. The original textured α2 grains experienced the circle of elongated, fractured and equiaxed proceedings, which were the main reasons of obtaining higher superplastic elongations and the anisotropic of superplasticity was be with all deformation conditions. The coarser and more volume fraction of α2 grains was benefite to the superplasticity of TAC-1B under certain conditions. O phase transformaiton will be strain induced at 1000℃, which will increase the capability of resistanceof neck-shrink with higher superplastic elongation.

关 键 词：Ti_3Al基合金 超塑性 最大m值法 各向异性 

分 类 号：V231.9[航空宇航科学与技术—航空宇航推进理论与工程]