低氢含量工业纯钛循环变形的微观结构——Ⅱ.氢化物的溶解和应变诱发氢化物的形成  

MICROSTRUCTURE OF CYCLICALLY DEFORMED TITANIUM WITH LOW HYDROGEN CONCENTRATION II. Dissolution of 7 Hydrides and Formation of Strain Induced Hydrides

作　　者：陈常强[1] 李守新[1] 李广义[1] 艾素华[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《金属学报》2004年第3期241-244,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金50271075;国家重点基础研究发展规划项目G19990650资助

摘　　要：对均匀弥散分布着γ氢化物的低氢含量的工业纯钛进行循环疲劳试验,发现滑移带能够穿过氢化物的共格界面,使氢化物发生塑性剪切变形,由于位错周围的氢气团能够在位错的拖拽下,随同位错一起运动,所以位错的运动能够促使氢原子沿滑移带扩散。滑移带穿过氢化物的过程伴随有氢原子沿滑移带的扩散,材料中原有的氢化物在滑移带的冲击下,由于局部的氢原子浓度太低,而重新溶解,同时位错也会带着氢气团在氢化物处塞集,引起氢原子的局部富集;并导致应变诱发氢化物的产生,研究表明这个可逆相变过程由位错运动诱发的氢原子扩散所控制。Cyclic testes were conducted on commercially pure titanium with low hydrogen concentration, in which 7 hydrides dispersed homogenously. It was found that dislocations can transfer through the coherent interface and result in the plastic shear deformation of 7 hydrides. Because hydrogen atmosphere around dislocations can be dragged and move along with the dislocations, so hydrogen atoms diffuse preferentially along the slip bands. The process of slip band transfering through the hydrides accompanies the diffusion of hydrogen atoms along slip bands. The preexisting hydride may dissolve under the impingement of slip bands, due to the decrease of the localized hydrogen concentration. Also the dislocations with the hydrogen atmosphere may pile up at the hydride interface, and hence result in the increase of the hydrogen concentration, then strain induced hydrides would appear. The reversible transformation is considered to be diffusion-controlled and influenced by dislocations movement.

关 键 词：氢化物 循环形变 位错 应变诱发氢化物 

分 类 号：TG113.25[金属学及工艺—物理冶金] TG115.21[金属学及工艺—金属学]