微螺钉用细晶两相钛合金韧化因素及研究现状-中国材料进展

文章信息/Info

Title:: Toughening Factors and Research Status of Fine-Grained Titanium Alloy for Micro-Screw

作者:: 王凯旋1; 邵晖2; 单迪2; 孙峰1; 赵小花1; 刘向宏1; (1. 西部超导材料科技股份有限公司，陕西西安 710018) (2. 西安理工大学，陕西西安 710048)

Author(s):: WANG Kaixuan1，SHAO Hui2，SHAN Di2，SUN Feng1，ZHAO Xiaohua1，LIU Xianghong1

Keywords:: two-phase titanium alloy; fine grain; strength; toughness; heat treatment

摘要:: 含有大量位错和高角度晶界的大变形两相微螺钉用细晶钛合金具有良好的拉伸和疲劳性能，然而变形合金局部位错、织构和微观应力影响合金的韧性，引起了国内外材料研究者的关注。目前，退火热处理是改善变形钛合金韧性的有效措施，但是变形畸变能诱发细小晶粒快速长大，导致合金强度大幅度下降，不利于提高其综合力学性能。概述了典型两相钛合金组织特征参数和微观应力对其韧化的影响规律，以Ti-6Al-4V合金为例分析了等径通道塑性变形、高压扭转、累积变形、搅拌摩擦等大变形高强钛合金韧化的研究现状。同时，概述了一种新型电热处理对大变形Ti-6Al-4V合金组织和韧化的影响规律，并展望了其在钛合金领域的研究方向和目前存在的基础科学问题。

Abstract:: Fine-grained large deformation two-phase titanium alloys with large amount of dislocations and high-angle grain boundaries have good tensile and fatigue properties. However, the partial dislocations, textures and micro-stress in the deformed alloy may not be beneficial for improving the toughness, which has attracted the attention of researchers at home and abroad. The annealing treatment is an effective method to regulate the strength-toughness synergy of the deformed alloy. However, the growth rate of fine grain could be accelerated by the deformation storage energy, which could result in the decrease in the strength. Therefore, the excellent comprehensive property is difficult to obtain by the traditional method. In this paper, the influence of microstructural parameters and microstress on the toughness of titanium alloy is firstly reviewed. Secondly, the strength and toughness of titanium alloy are described based on the analysis of the large deformation mechanism (ECAP, HPT, multistep deformation and FSP). Finally, the effect of a pulse current heating on the microstructure and toughness of high strength titanium alloy is identified, and the research direction and problem are further discussed in the current assisted deformation or heating processes of titanium alloys.