Development Of Multi-frequency Ultrasonic Power Supply For Residual Stress Removal

Ultrasonic vibration aging is a new method of using ultrasonic technology to remove residual stress.Ultrasonic vibration aging has a better effect on removing residual stress than traditional methods.Because this method ignores the residual stress in the under-vibration zone during vibration,it leads to the disadvantages of uneven vibration energy and incomplete residual stress removal,so it cannot meet the effective residual stress removal effect.Aiming at the current problems of using ultrasonic vibration aging to remove residual stress,combined with the control algorithm,a multi-frequency superposition and continuously adjustable frequency is realized.The excitation energy of different positions tends to be consistent,and the excitation time of different frequencies is proportional to the stability and efficiency.The residual stress is removed with a multi-frequency ultrasonic power supply.The main research contents of this paper are as follows:(1)According to the requirements and characteristics of the multi-frequency ultrasonic power supply for residual stress removal,the various modules of the ultrasonic power supply are designed and simulated.The signal generation module adopts STM32F103RCT6single-chip microcomputer and peripheral circuits.The power amplifier drive circuit in the power amplifier module is mainly KD301 driver.The power amplifier circuit adopts the method of combining D-type voltage switching power amplifier circuit and hard parallel IGBT parallel mode,frequency scanning The tracking circuit uses a combination of the maximum current search method and the phase-locked frequency sweep tracking technology.Through Proteus to simulate and analyze some modules,the results show that each module of the ultrasonic power supply has a stable signal waveform.(2)The control algorithm is used to analyze the ultrasonic vibration energy at different positions under multi-frequency superposition,and the excitation time ratio under the multi-frequency superposition is obtained,and the excitation energy at different positions is uniformized.Aiming at the shortcoming of the current ultrasonic vibration aging to remove the uneven residual stress,through the combination of ultrasonic vibration energy distribution analysis and the designed control algorithm,the excitation time under different frequency superposition is obtained and the ratio is formed.In order to verify the feasibility of the algorithm,the resonant frequency under multi-frequency superposition is fitted with the excitation time ratio,and the ultrasonic vibration energy at different positions tends to be uniform,so that the residual stress can be efficiently and stably removed.(3)Build an ultrasonic power experiment platform to test the output performance,frequency scanning and tracking performance,and multiple frequency superposition performance of the ultrasonic power supply.The test shows that the signal generation in the ultrasonic power supply and the power amplifier module have complete waveform output;in terms of frequency scan tracking performance,the actual resonant current under no-load state differs from the resonant current of automatic scan tracking by 117 m A,which simulates the residual stress removal state In the comparison of automatic scanning and tracking with or without frequency,the current has dropped by 40%,the frequency has dropped by 1.21 k Hz,and the phase difference is 57.58°;in the process of testing multiple frequency superimposed output performance,the specific resonance is used as the target and the excitation time obtained by the control algorithm The matching output is performed with the resonance frequency,and the result shows that the output waveform is stable and has a certain proportion of the waveform.