多道次热循环条件下TA15钛合金组织形态的定量研究  

Quantitative analysis of the microstructure under multi-pass thermal cycle of TA15 titanium alloy

作　　者：梅文佳[1] 杨合[1] 樊晓光[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《塑性工程学报》2014年第4期79-86,共8页Journal of Plasticity Engineering

基　　金：国家"973"计划资助项目(2010CB731701);国家自然科学基金重点资助项目(50935007);国家自然科学基金青年资助项目(51205317)

摘　　要：钛合金大型复杂整体构件等温局部加载成形中的多道次热循环特性是影响组织形态的重要因素,文章设计并完成了多道次热循环实验,定量研究了循环参数对TA15钛合金组织形态的影响。结果表明,多道次热循环对最终组织的影响可看作不同初始组织和单一热循环对组织的共同作用;初始等轴组织经过热循环可获得双态组织,初生等轴α相(αp)体积分数和晶粒尺寸随着温度的升高均先缓慢变化然后加速降低;初始双态组织进行热循环可获得三态组织,其中αp形态接近初始组织,片层α相(αs)体积分数随温度升高呈指数型下降,αs平均厚度则缓慢增加;初始三态组织进行热循环仍然可获得三态组织,其中αp的体积分数和尺寸略微增大,αs体积分数随温度升高仍呈指数型下降,αs平均厚度先增加后减小。研究结果可为TA15钛合金等温局部加载成形过程中的微观组织预测与控制提供依据。The multi-pass thermal cycle characteristic ,which is obviously presented in the isothermal local forming of large-scale complex component of titanium alloy ,has great influence on the microstructure morphology . To this end ,a multi-pass thermal cycle experiment was designed and carried out to quantitatively analyze the effect of the cycle parameters on the microstructure of TA15 titanium alloy . The results show that the effect of multipass thermal cycle on the final microstructure can be seen as the combined effects of both different primary microstructure and single thermal cycle . The primary equiaxed microstructure will transform into bimodal microstructure through thermal cycle ,the volume fraction and grain size of αp first change slowly and then decrease accelerately with the increase of the heating temperature . The primary bi-modal microstructure will transform into tri-modal microstructure through thermal cycle ,and the morphology of αp almost keep the same ,while the volume fraction of αs decreases exponentially and the average thickness of αs increases slowly with the increase of heating temperature . The primary tr-modal microstructure will still transform into tri-modal microstructure through thermal cycle ,the volume fraction and grain size ofαp increase slightly with the increase of heating temperature ,while the volume fraction of αs decreases exponentially and the aver-age thickness of αs first increases and then decreases . The results obtained can provide a guide for prediction and control of microstructure during the isothermal local forming of TA15 titanium alloy .

关 键 词：TA15钛合金 成形成性一体化 多道次热循环 组织形态 定量分析 

分 类 号：TG319[金属学及工艺—金属压力加工]