置氢TC4钛合金激光焊接接头超塑变形性能研究

Superplasticity of Ti-6Al-4V laser butt weld joint Processed with Hydrogenation

摘要:

摘 要: 置氢处理可以调节TC4钛合金激光焊接接头超塑性变形组织状态，提高焊接接头超塑变形组织均匀性；本项目采用置氢处理研究了TC4钛合金激光焊纵向焊缝接头超塑性变形行为，是置氢提高钛合金激光焊接接头超塑变形均匀性的基础性研究。主要研究了置氢量对TC4激光焊接接头峰值流变应力、焊板延伸率、组织均匀性的影响。研究表明：激光焊板超塑性变形中的峰值流变应力随含氢量的增大而增大，随变形温度的升高而降低，随变形速率的增大而增大；试样延伸率随含氢量的增大而减小，随变形温度的升高而增大，随变形速率的增大而减小。在含氢量0.291%，变形温度920℃，变形速率10-4S-1时，峰值流变应力最小达到20.7MPA，焊板延伸率达到最大312%。置氢TC4钛合金激光焊接接头可以承受超塑性变形而不破坏，在初始应变速率为10-3S-1和10-4S-1时，试样峰值流变应力低于80MPA。

Abstract:

Abstract: Hydrogenation can adjust state of microstructure of superplasticity of Ti-6Al-4V laser butt weld joint and improve the superplastic deformation uniformity of microstructure . The project adopped the treatment of hydrogenation study the deformation behavior of super-plasticity of Ti-6Al-4V laser butt weld joint. The project is the basic research that hydrogenation can improve the superplastic deformation uniformity of microstructureThe main research is that the content of hydrogen affected peak flow stress, welding plate extending rate, uniformity of microstructure . The results revealed that the peak flow stress enlarged with the increasing of the content of hydrogen, reduced with the rising of deformation temperature, enlarged with the increasing of strain rate; elongation of specimen rduced with the increasing of the content of hydrogen, enlarged with the rising of deformation temperature, reduced with the increasing of strain rate. The peak flow stress reaches a minimum 20.7MPA, weld plate maximum elongation reach to 312% in the situation of hydrogen content of 0.291% in the deformation temperature of 920 ℃, strain rate 10-4S-1. Ti-6Al-4V laser butt weld joint with hydrogen can under superplastic deformation without failure，In the initial strain rate of 10-3S-1 and 10-4S-1, the peak flow stress is less than 80MPA.