利用CO₂激光相变热处理技术对TC4钛合金电子束焊缝进行了处理，研究了激光功率、光斑直径、辅助气体等激光工艺参数对电子束焊缝残余应力分布的影响。实验结果表明，激光相变热处理改善了焊缝残余应力的分布，使焊缝表面残余应力由拉应力转变为压应力，其压应力值随着激光功率的增加而增大，随着激光光斑直径的减小而增加；辅助气体为O₂时残余压应力值比辅助气体为N₂大30～40MPa，激光相变热处理显著提高了TC4钛合金电子束焊缝的残余压应力及其使用寿命。

  In this study,  an effective control method and strategy based on fuzzy neural network has been developed for gas injection pressure accurate control in gas-assisted injection. A fuzzy neural network controller with five layers and its control algorithm are established.  The learning ability of neural network is used to optimize the rules of the fuzzy logic so as to improve the adaptability of system.  The simulation of the system capability and three segmental injected pressure control are carried out under the environment of MATLAB and the results show that this theoretic model is feasible, and the control system has good characteristics and control action.