长度标准器超声清洗参数设计研究

Design and study on length standard ultrasound cleaning parameters

针对长度标准器在超声清洗过程中产生的损伤现象,开展了影响超声空蚀作用因素的研究。根据Rayleigh-Plesset方程解得气泡半径演化曲线,得出不同气核初始半径、频率和温度下,空化泡首次缩塌时的泡内最高温度与正应力响应,进而分析长度标准器损伤原因。再提出了一种新的失质法,研究超声频率、温度和超声辐射时间对长度标准器的去污效果与腐蚀阶段的影响,实验结果表明,长度标准器的清洗过程分为空化清洗期、空蚀孕育期和空蚀加速期3个阶段,并且在去除油污的过程中,空蚀作用的影响十分微小。当溶液温度60℃,超声频率28 kHz,辐射时间1 min的情况下,会有较好的清洗效果。

Aiming at the damage phenomena of length standard in ultrasonic cleaning process,the factors influencing the ultrasonic cavitation erosion effect are studied.According to Rayleigh-Plesset equation,the evolution curve of bubble radius is solved,and the maximum temperature and normal stress response in the bubble for the first collapse of the cavitation bubble under different initial radius,frequency and temperature of the gas nucleus are obtained,and then the damage reason of the length standard is analyzed.A new method of deterioration is proposed to study the effects of ultrasonic frequency,temperature and ultrasonic radiation time on the decontamination effects and corrosion stages of the length standard.The experiment results show that the cleaning process of the length standard is divided into three stages:cavitation cleaning stage,cavitation erosion incubation stage and cavitation erosion acceleration stage.In the process of removing oil pollution,the effect of cavitation erosion is very small.When the solution temperature is 60℃,the ultrasonic frequency is 28 kHz and the radiation time is 1 minute,the cleaning effect will be better.