等通道转角挤压(ECAP)是一种制备超细晶材料的专有技术，在制备高性能超细晶钛合金紧固件方面具有巨大应用前景。本项目针对钛合金ECAP变形温度高、显微组织和力学性能难调控等问题，依据热氢处理可以提高钛合金塑性、降低变形温度的特点，创新性地提出氢致钛合金温热ECAP剧烈形变晶粒细化及其组织调控的新方法。围绕该方法中的关键科学问题，从宏观变形行为和微观结构演变机理出发，研究置氢钛合金的温热塑性变形行为及其显微组织变化规律；开展氢致钛合金ECAP剧烈形变晶粒细化及ECAP形变超细晶置氢钛合金的热变形行为研究，并利用真空退火脱氢处理对超细晶钛合金显微组织和力学性能进行精细调控，阐明氢致相变对高畸变能形变钛合金再结晶行为影响机理和氢与细晶化协同作用钛合金热塑性变形机制，从而实现ECAP制备超细晶钛合金微观组织与力学性能的有效控制，为高性能超细晶钛合金紧固件加工技术奠定理论和技术基础。

Equal channel angular extrusion (ECAP) is a special technology for preparing ultra-fine grained materials, which has great potential application prospect in preparing high-performance ultra-fine titanium alloy fasteners. However, there are several problems such as high deformation temperature, difficult to control microstructure and mechanical properties and grain growth in post-annealing process etc. According to the existing research results that the thermohydrogen treatment technology can improve the plasticity and reduce deformation temperature of titanium alloy, a novel method of warm ECAP induced by thermohydrogen treatment was used for titanium alloy grain refinement and microstructure control. Based on the key scientific problem, macro-deforming behavior and mechanism of microstructure evolution are studied in this project. The medium-temperature plastic deformation behavior and microstructure evolution of hydrogenated titanium alloy will be investigated. The grain refinement of hydrogenated titanium alloy processed by ECAP severe plastic deformation and its hot deformation behavior will be studied subsequently. The microstructure and mechanical properties of ECAP deformed ultra-fine titanium alloy will be precisely controlled by vacuum annealing dehydrogenation heat treatment. The effect of hydrogen-induced phase change on the recrystallization behavior of titanium alloy with high distortion deformation will be clarified, so well as the hot deformation mechanism of titanium alloy processed by the interaction of hydrogenation and grain refinement. Finally, it will achieve the objection of effective control of the microstructure structures and mechanical properties of ultra-fined titanium alloy prepared by ECAP. The research findings can provide foundation of theory and technology for the forming technology development of high-performance ultra-fine grain titanium alloy fasteners.