置氢钛合金室温塑性反常应变速率效应研究

It is difficult for titanium alloy to form, although it has important applications in the fields of aerospace and marine engineering. Improvement of room-temperature plasticity of titanium alloy is the key to achieve high-speed and high-efficiency plastic forming of titanium alloy at room temperature. Based on our previous studies, we find the room-temperature plasticity of hydrogenated titanium alloy has an abnormal strain rate effect, hydrogenation process can improve greatly the plasticity of titanium alloy under compression test at room temperature and high strain rate from low plasticity to near high plasticity (plasticity increases by more than 159.6%). In this program, we will further study the abnormal strain rate effect and its mechanism on the room-temperature plasticity of hydrogenated titanium alloys with different hydrogen contents, clarify the reason of different phenomenon between strain hardening and strain softening of hydrogenated titanium alloys with different hydrogen contents compressing at different strain rates, and reveal the plastification mechanism of hydrogenated titanium alloys deforming at room temperature and high strain rate, determine the optimal hydrogenation process and room-temperature plastic forming process at high strain rate, achieve the plastic forming of hydrogenated titanium alloy at room temperature and high strain rate. Based on the above studies, we will apply this technology to form large bolt of titanium alloy at room temperature and high strain rate, and lay the foundation for the application of this technology in the high-speed and high-efficiency plastic forming of large titanium alloy structural parts at room temperature, and provide new method for the advanced manufacturing of titanium alloy.

钛合金在航空航天和海洋工程等领域有重要应用，但是其塑性成形一直是一个难题，而改善难变形钛合金的室温塑性是实现钛合金结构件室温高速高效塑性成形的关键。申请人在前期钛合金室温氢增塑工艺研究中，发现置氢钛合金的室温塑性具有反常应变速率效应，置氢可以大幅度提高钛合金在室温快速塑性变形时的塑性（增幅＞159.6%），可从低塑性提升至接近或达到高塑性。本项目将进一步研究不同氢含量置氢钛合金室温塑性反常应变速率效应的变化规律及其机制，揭示不同氢含量置氢钛合金在不同的应变速率下室温塑性变形时的应变硬化和应变软化机理及其室温快速塑性变形增塑机理，制定最佳氢处理工艺和最佳室温快速塑性成形工艺，实现置氢钛合金的室温快速塑性成形。在上述研究基础上，本项目将应用该技术实现钛合金大直径螺栓的室温快速塑性成形，为该技术在钛合金大规格复杂结构件室温高速高效塑性成形中的应用奠定基础，为钛合金高端制造应用提供新的技术手段。

针对钛合金室温塑性低，导致其结构件室温塑性成形困难的难题，基于申请人前期研究发现的置氢钛合金室温塑性具有反常应变速率效应的现象，本项目研究揭示了不同氢含量置氢钛合金室温塑性反常应变速率效应的变化规律及其微观机制，揭示了不同氢含量置氢钛合金在不同的应变速率下室温塑性变形时的应变硬化和应变软化机理及其室温快速塑性变形增塑机理，制定了利于钛合金室温快速塑性成形的最佳氢处理工艺和最佳室温快速塑性成形工艺，建立了置氢钛合金室温快速塑性成形技术，并以螺栓作为典型结构件实现了置氢钛合金结构件的室温快速塑性成形，验证了本项目所提出的置氢钛合金室温快速塑性成形技术，本项目所提出的氢处理工艺可以使钛合金的室温塑性从低塑性区提升至高塑性区，置氢钛合金的室温塑性指标可达71%，比原始钛合金提高了244%，塑性是钛合金结构件塑性成形的关键共性基础问题之一，塑性的大幅度提高为钛合金复杂结构件的室温高速高效塑性成形奠定了坚实的理论基础，本项目研究可以促进室温塑性成形技术在难变形钛合金塑性成形中的应用，可以改变难变形钛合金传统的塑性成形方式，实现将难变形钛合金的塑性成形方式由高温塑性成形转变为室温塑性成形，为钛合金高端制造应用提供新的技术手段，有望促进钛合金结构件在航空航天、海洋工程、武器装备等国家战略领域的进一步推广应用。