Microstructure Control for Attaining Over 2Gpa of Tensile Strength in Beta Titanium Alloys

通过微观结构控制使 Beta 钛合金的拉伸强度达到 2Gpa 以上

• 批准号: 02650512
• 负责人: NIWA Naotake
• 金额: $ 1.09万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650512/
• 关键词: titanium alloy; beta titanium alloy; Ti-15V-3CR-3Sn-3Al; Cold-working; aging; mechanical property; duplex-aging; 冷間加工

The features of the beta titanium alloy Include Its superior cold-formability in the solution-treated state and Its Increased strength after undergoing subsequent aging-treatment. Consequently, the method of aging after cold-forming Is a heat-treatment method which utilizes the features of the beta titanium alloy. The heat-treatment method of aging after cold-working is known to remarkably promote the aging response and fine precipitation of alpha phase in commercial beta titanium alloy. It was reported that, compared with the method of aging without cold-working after solution-treatment, this heat-treatment method Improved the balance between strength and ductility of commercial beta titanium alloy Ti-, 13-llCr-3Al, however, It was considered, - that this heat treatment method reduced ductility while aiming to achieve high strength and that the strength-ductility balance could not be Improved for commercial beta titanium alloy Ti-15V-3Cr-3Sn-3Al. Mechanical properties were studied by tensile test of Ti-15V-3Cr-3Sn-3AI alloy obtained by duplex-aging after cold-swaging, i. e. aging at high temperatures followed by re-aging at a lower temperature. Combinations of short-time aging at 823K, 873K and 923K and re-aging at 673K have greatly Improved the strength-ductility balance of this alloy, realizing high strength with adequate tensile elongation. This duplex-aging process further diminishes the Influence of reduction of cold-swaging on the mechanical properties after aging.

β钛合金的特征包括其在固溶处理状态下的上级冷成形性和其在经历随后的时效处理后的增加的强度。因此，冷成形后时效的方法是利用β钛合金的特性的热处理方法。已知冷加工后时效的热处理方法显著促进商业β钛合金中α相的时效响应和细析出。与固溶处理后不进行冷加工的时效方法相比，这种热处理方法改善了工业β钛合金Ti-13- 11 Cr-3Al的强度和塑性之间的平衡，但认为，- 这种热处理方法降低了延展性，同时旨在实现高强度，并且强度-商业β钛合金Ti-15 V-3Cr-3Sn-3Al的塑性平衡没有得到改善。采用拉伸试验研究了Ti-15 V-3Cr-3Sn-3Al合金经冷挤压后再进行双级时效的力学性能。e.在高温下老化，然后在较低温度下再老化。823 K、873 K和923 K短时时效与673 K再时效相结合，大大改善了该合金的强塑平衡，实现了高强度和足够的延伸率。该时效工艺进一步减小了冷挤压变形量的减少对时效后力学性能的影响。