通过物理实验、ANSYS有限元数值模拟和试验相结合, 研究了超声波在BT20钛合金熔池中的传播作用机理, 设计阶梯型变幅杆, 并将之用于激光沉积修复过程中。物理实验结果表明, 声流效应在BT20钛合金熔池中占据主导地位。模拟结果表明, 阶梯型变幅杆的设计可以最大化的扩大振幅且振幅分布较为均匀, 做成可拆卸的变幅杆可以在满足试验条件的基础上增加试验的灵活性。将超声作用在熔池内部, 可以加快冷却速度, 缩短凝固时间, 使沉积层中的α片层组织变短, 可使沉积修复区域硬度提高。

The propagationand acting principle of the ultrasonic transmission in the BT20 titanium alloy molten poolare researched by finite element numerical simulation、 experimentand physical experiment, and the ladder amplitude transformer is designed, which is applied into the laser deposition repairing. The result of physical experiment shows that, the acoustic streaming dominates the propagation characteristics in the molten pool, the design of ladder amplitude transformer can maximize the expansion of the amplitudeuniformly.The ladder amplitude transformer can not only meet the basic experiment requirement, but also increase the flexibility of the test. The Ultrasonic can increasethe cooling rate, and shorten the coagulation time, and the α phase of the deposition,and alsoincrease the microhardness.