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钛合金,特别是含有少量β稳定剂的α-β钛合金,是首批发现具有超塑性的材料之一。这使钛的超塑加工很早就得到应用。但是,同时要求高温和保护气氛的钛合金冶金的复杂性,使基本的实验工作遇到很大困难。然而,近来有关钛合金超塑性的著作明显增加,认识水平也有显著提高。本文将着重评述适合超塑成形的两相钛合金的新进展,也将论及α和β相对体积分数、添加β稳定剂、扩散系数、变形机制、温度和应变速率等对超塑变形(特别是对两相合金系统)的影响。通过实验和分析,逐一讨论了显微结构(包括晶粒大小和形状)和加工历史对应变速率敏感性、延伸率以及成形性能的作用,说明了晶粒大小随变形而变化以及应变、应变速率和温度对晶粒尺寸稳定性的影响,这是了解钛合金超塑变形的一个重要方面。关于显微和机械的缺陷对总伸长率以及可变因素(例如应变速率和温度)对加工的影响,将从理论的和实验的观点进行讨论。最后,在生产条件下就这些工艺参数对钛合金超塑成形的影响,以及为得到满意的构件所必须的压力和气氛控制,将在文章的结论部份提到。
Titanium alloys, especially α-β titanium alloys with a small amount of β-stabilizers, were among the first to find superplastic materials. This makes titanium superplastic processing very early application. However, the complexity of titanium alloy metallurgy, which simultaneously requires high temperatures and a protective atmosphere, presents great difficulties in basic experimental work. However, the recent writings on the superplasticity of titanium alloys have significantly increased and the level of awareness has also risen significantly. This article will highlight recent advances in two-phase titanium alloys suitable for superplastic forming, and will also address the relative volume fraction of α and β, the addition of β stabilizers, diffusion coefficients, deformation mechanisms, temperature and strain rates to superplastic deformations Is the impact of two-phase alloy system). The effects of microstructure (including grain size and shape) and processing history on strain rate sensitivity, elongation and formability were discussed experimentally and analytically, and the effect of strain on strain rate and strain rate And temperature on the grain size stability, which is to understand the titanium alloy superplastic deformation is an important aspect. The effects of microscopic and mechanical defects on the total elongation and on the processing of variable factors such as strain rate and temperature will be discussed both theoretically and experimentally. Finally, the impact of these process parameters on the superplastic forming of titanium alloys under production conditions, as well as the pressure and atmosphere control necessary to obtain a satisfactory component, will be mentioned in the concluding section of the article.