Ti-6Al-4V合金双半球结构脉冲电流辅助超塑成形

Pulse Current Auxiliary Superplastic Forming of Ti-6Al-4V Alloy Double Hemisphere Structure

针对Ti-6Al-4V合金板材超塑成形能耗高、效率低的问题,提出了一种脉冲电流辅助超塑成形工艺。该工艺将成形坯料直接串联到脉冲电流回路,利用脉冲电流迅速将坯料加热至超塑成形温度。通过脉冲电流加热实验,分析了平均脉冲电流密度对坯料温度及升温速率的影响。结果表明,采用该加热方式可将坯料加热时间从数十分钟缩短至几十秒,能量消耗降至传统工艺的20%左右,极大地提高了加热效率、降低了能耗,实现了节能环保的绿色超塑成形技术。利用该工艺成形了Ti-6Al-4V合金双半球结构,并分析了在脉冲电流辅助工艺条件下细晶态Ti-6Al-4V合金的超塑变形机制。

A pulse current auxiliary superplastic forming（PCASF） is developed to solve the problems of high energy consumption and low efficiency of Ti-6Al-4V alloy superplastic forming.In this process,the sheet was connected in series with a pulse current circuit and heated directly by the pulse current.Through the pulse current heating experiment,the effects of the average current density on the temperature and the rate of temperature rise have been studied.The result indicates that the heating time is reduced from tens of minutes to dozens of seconds,and the energy consumption is reduced to 20% compared to the traditional process.Thus the heating efficiency is improved and the energy consumption is reduced greatly.The green superplastic forming technology with the merit of energy conservation becomes possible.The double hemisphere structure of Ti-6Al-4V alloy has been formed by PCASF and its deformation mechanism has been studied.