TB8钛合金热变形行为及热镦性能研究

Research on hot deformation behavior and hot heading performance of TB8 titanium alloy

TB8钛合金是一种超高强度亚稳定β钛合金,因其具有良好的抗氧化性能、耐腐蚀性能和综合力学性能而广泛应用于航空航天领域。为研究某型机用TB8钛合金十二角螺栓的热镦成形工艺,首先利用Gleeble-1500D热模拟试验机对不同温度和应变速率下TB8钛合金试样进行了等温压缩试验,得到其不同变形条件下的真实应力-应变曲线并分析其热变形行为。其次将试验得到的数据导入到Deform-3D有限元模拟软件中对TB8钛合金十二角螺栓热镦工艺进行有限元模拟,对热镦成形关键工艺参数建立了正交试验优化方案,通过优化得到了TB8钛合金热镦成形工艺参数,对优化后的成形过程进行了分析,分析了等效应力场分布、损伤值分布、模具应力分布等。最后根据优化得到的热镦工艺参数,结合实际生产设备设计相应模具,并进行了热镦工艺试验,试验结果表明,数值模拟结果和实际生产结果基本一致,试验得到的TB8钛合金十二角螺栓经后续机械加工后没有出现缺陷,说明文章的热镦工艺可行,可用于指导TB8钛合金十二角螺栓及其他类似零件的实际生产。

TB8 titanium alloy is an ultra-high strength and metastable materialβTitanium alloys are widely used in the aerospace industry due to their excellent oxidation resistance,corrosion resistance,and comprehensive mechanical properties.To study the hot forging process of TB8 titanium alloy twelve corner bolts for a certain type of machine,isothermal compression experiments were conducted on TB8 titanium alloy specimens at different temperatures and strain rates using the Gleeble-1500D thermal simulation testing machine.The true stress-strain curves under different deformation conditions were obtained and their hot deformation behavior was analyzed.Secondly,the experimental data was imported into the Deform-3D finite element simulation software to perform finite element simulation on the hot heading process of TB8 titanium alloy twelve-angle bolts.An orthogonal experimental optimization scheme was established for the key process parameters of hot heading forming.Through optimization,the TB8 titanium alloy hot heading forming process parameters were obtained.The optimized forming process was analyzed,including equivalent stress field distribution,damage value distribution,and mold stress distribution.Finally,based on the optimized hot heading process parameters and combined with actual production equipment,corresponding molds were designed and hot heading process experiments were conducted.The experimental results showed that the numerical simulation results were basically consistent with the actual production results.The TB8 titanium alloy twelve-angle bolt obtained from the experiment did not show any defects after subsequent mechanical processing,indicating that the hot heading process proposed in this article is feasible,This has certain guiding significance for the actual production of TB8 titanium alloy twelve-point bolts and other similar parts.