Ti_(2)AlNb合金蜂窝结构电流辅助成形-扩散连接工艺研究

Research on the Current Assisted Roll Forming of Ti_(2)AlNb Alloy Corrugated Sheet

Ti_(2)AlNb合金蜂窝结构采用辊弯-热校形-点焊复合工艺制备,存在工艺周期长、能耗高、构件精度低、可靠性差等缺陷。本文提出Ti_(2)AlNb合金蜂窝瓦楞板电流辅助辊压成形工艺,利用局部成形位置的高电流密度抑制构件回弹。同时,采用扩散连接工艺制备蜂窝结构,实现蜂窝结构的可靠连接。当电流密度高于阈值(20 A/mm^(2))时,电流密度对于V形弯曲回弹的抑制作用显著。当电流密度达到60 A/mm^(2)时,V形弯曲回弹已基本消除。在瓦楞板电流辅助辊压成形过程中,当最大电流密度增大至66 A/mm^(2)时,瓦楞板的成形角度由125.5°降低为121.3°。设计了Ti_(2)AlNb蜂窝结构扩散连接工装,在970℃/15 MPa/2 h热压工艺参数下,制备了蜂窝结构样件,六边形元胞的尺寸一致、精度高。

The honeycomb structure of Ti_(2)AlNb alloy is prepared by the integrated process of roll bending and thermal adjustment and spot welding,which has some defects such as long process period,high energy consumption,low component precision and poor reliability.In this paper,the current assisted roll forming process of Ti_(2)AlNb alloy honeycomb corrugated sheets is proposed,and the high current density in local forming position is used to inhibit springback defects.At the same time,the honeycomb structure is prepared by diffusion bonding technology to realize the reliable connection of the honeycomb structure.When the current density is higher than the threshold(20 A/mm^(2)),the current density has a significant inhibitory effect on the springback of V-shaped bending.When the current density reaches 60 A/mm^(2),the springback defect is basically eliminated.When the loading current increases to 66 A/mm^(2) during the current assisted roll forming process,the forming angle of the corrugated sheet is reduced from 125.5°to 121.3°.The Ti_(2)AlNb honeycomb structure diffusion bonding tool was designed.The honeycomb structure sample was prepared under hot pressing process parameters of 970℃/15 MPa/2 h.The size of hexagonal cell was the same and the precision was high.