Advanced Processing of a Near Beta Titanium Alloy

钛合金由于其高的比强度和优异的耐腐蚀性，已广泛应用于航空航天、化工和生物医学等行业。对于下一代更轻、更节能的飞机结构，从减轻重量和机械性能的角度来看，与工业主力Ti-6Al-4V（最广泛使用的α+β合金）相比，在机身、转向架梁、襟翼导轨、短舱、挂架和起落架组件中使用高强度近β钛合金将具有成本效益。空客和波音等主要航空航天制造商已经开始使用锻造近β钛合金作为起落架部件。近β钛合金具有广阔的应用前景。然而，虽然对近β钛合金设计进行了大量研究，但从工业制造的角度来看，特别是在焊接，成型和增材制造（AM）等过程中，了解微观组织-机械性能相关性的工作很少。近β钛合金的性能与其内部组织密切相关，其内部组织通常由多个相和析出相组成。这些析出相的体积分数、尺寸、形态和分布对近β钛合金的力学性能有重要影响。因此，全面而详细地了解相变和微观结构演变对于优化各种应用的机械性能至关重要。我建议使用各种工业制造工艺，如连接，成形和AM，对近β钛合金进行详细研究。该研究计划未来五年的主要目标是：**（1）优化各种工业制造方法的工艺参数。(2)学习如何通过不同的热加工和热机械加工来控制微结构。* （3）定量研究单个显微组织特征，并将其与相应的力学性能相关联。

Summary of Proposal***Titanium alloys have been widely used in the aerospace, chemical, and biomedical industries due to their high specific strength and excellent corrosion resistance. For the next generation of lighter and energy-efficient aircraft structures, the use of high strength near-β Ti-alloys in the fuselage, bogie beam, flap track, nacelles, pylon, and la195nding gear assemblies will be cost effective from the perspective of weight reduction and mechanical properties compared to the industry workhorse Ti-6Al-4V, the most widely used α+β alloy. Major aerospace manufacturers like Airbus and Boeing have started to use forged near-β Ti-alloys as landing gear components. It is expected that near-β Ti-alloys will gain wider applications in the future. However, while significant research has been conducted on near-β Ti-alloy design, little work has been done to understand the microstructure-mechanical properties correlations from the industrial manufacturing point of view, especially during processes such as, welding, forming, and additive manufacturing (AM).******The properties of near-β Ti-alloys are highly dependent on their internal microstructure, which often is composed of multiple phases and precipitates. The volume fraction, size, morphology, and distribution of these precipitates can significantly influence the mechanical properties of the near-β Ti-alloys. Therefore, a complete and detailed understanding on phase transformations and microstructural evolution are crucial to optimize the mechanical properties for various applications. I am proposing a detailed study on a near-β Ti-alloy using various industrial manufacturing processes, such as joining, forming, and AM. The main objectives of this proposed research program for the next five years are:******(1) To optimize the processing parameters for various industrial manufacturing methods.***(2) To learn how to control the microstructures through different thermal and thermo-mechanical processing. ***(3) To study individual microstructural features quantitatively and correlate it to the corresponding mechanical properties.