超聲波清洗是基于空化作用,即在清洗液中無數(shù)氣泡快速形成并迅速內(nèi)爆。由此產(chǎn)生的沖擊將浸沒在清洗液中的工件內(nèi)外表面的污物剝落下來。隨著超聲頻率的提高,氣泡數(shù)量增加而爆破沖擊力減弱,因此,高頻超聲特別適用於小顆粒污垢的清洗而不破環(huán)其工件表面。氣泡是在液體中施加高頻(超聲頻率)、高強度的聲波而產(chǎn)生的。因此,任何超聲清洗系統(tǒng)都必須具備三個基本元件:盛放清洗液的槽、將電能轉(zhuǎn)化為機械能的換能器以及產(chǎn)生高頻電信號的超聲波發(fā)生器。
Ultrasonic cleaning is based on cavitation, where countless bubbles rapidly form and implode in the cleaning solution. The resulting impact will peel off the dirt on the inner and outer surfaces of the workpiece immersed in the cleaning solution. With the increase of ultrasonic frequency, the number of bubbles increases and the blasting impact force weakens. Therefore, high-frequency ultrasound is particularly suitable for cleaning small particles of dirt without damaging the surface of the workpiece. Bubbles are generated by applying high-frequency (ultrasonic frequency) and high-strength sound waves in liquids. Therefore, any ultrasonic cleaning system must have three basic components: a tank to hold cleaning fluid, a transducer to convert electrical energy into mechanical energy, and an ultrasonic generator to generate high-frequency electrical signals.
(1)頻率:≥20KHz ,可以分為低頻,中頻,高頻3段。
(1) Frequency: ≥ 20KHz, can be divided into three bands: low frequency, medium frequency, and high frequency.
(2)清洗介質(zhì):采用超聲波清洗,一般兩類清洗劑:化學(xué)溶劑、水基清洗劑等。清洗介質(zhì)的化學(xué)作用,可以加速超聲波清洗效果,超聲波清洗是物理作用,兩種作用相結(jié)合,以對物件進行充分、徹底的清洗。
(2) Cleaning medium: Ultrasonic cleaning is used, and there are generally two types of cleaning agents: chemical solvents, water-based cleaning agents, etc. The chemical action of the cleaning medium can accelerate the effect of ultrasonic cleaning. Ultrasonic cleaning is a physical action that combines the two functions to thoroughly and thoroughly clean objects.
(3)功率密度:功率密度=發(fā)射功率(W)/發(fā)射面積(cm2)通常≥0.3W/cm2,超聲波的功率密度越高,空化效果越強,速度越快,清洗效果越好。但對于精密的、表面光潔度甚高的物件,采用長時間的高功率密度清洗會對物件表面產(chǎn)生“空化”腐蝕。
(3) Power density: Power density=Emission power (W)/Emission area (cm2), usually ≥ 0.3W/cm2. The higher the power density of ultrasound, the stronger the cavitation effect, the faster the speed, and the better the cleaning effect. However, for precision and highly polished objects, long-term high-power density cleaning can cause "cavitation" corrosion on the surface of the object.
(4)超聲波頻率:超聲波頻率越低,在液體中產(chǎn)生的空化越容易,產(chǎn)生的力度大,作用也越強,適用于工件(粗、臟)初洗。頻率高則超聲波方向性強,適用于精細的物件清洗。
(4) Ultrasonic frequency: The lower the ultrasonic frequency, the easier and more powerful the cavitation generated in the liquid. It is suitable for initial cleaning of workpieces (coarse and dirty). High frequency results in strong directionality of ultrasonic waves, suitable for fine object cleaning.
(5)清洗溫度:一般來說,超聲波在30℃-40℃時的空化效果。清洗劑則溫度越高,作用越顯著。通常實際應(yīng)用超聲波時,采用50℃-70℃的工作溫度。
(5) Cleaning temperature: Generally speaking, the cavitation effect of ultrasound at 30 ℃ -40 ℃. The higher the temperature, the more significant the effect of the cleaning agent. Usually, when applying ultrasound in practice, a working temperature of 50 ℃ -70 ℃ is used.