Influence Of Ultrasonic Power Research Articles

Rotary ultrasonic machining of woven CFRP composite in a cryogenic environment

In the present study, rotary ultrasonic machining (RUM) was adopted to perform drilling of carbon fiber reinforced plastics (CFRP) in a cryogenic environment. An L27 orthogonal array was selected to conduct experiments by varying the spindle speed (denoted as N), feed rate (denoted as f), and ultrasonic power (denoted as P). The thrust force (denoted as Fz), exit burr area, and surface roughness (denoted as Ra) were measured to evaluate the machining performance. The influence of process parameters and the regression model were derived for each output quality response. Additionally, multi-objective optimization was performed using desirability analysis, and the predicted levels were used for confirmation. The results indicated that the feed rate (f) contributed more to the thrust force (Fz) by 45.85% and a maximum thrust force was recorded at 0.1 mm/rev. A decrease in spindle speed (N) was associated with an increase in feed rate (f) and ultrasonic power (P), and it resulted in minimum exit burr area. The influence of ultrasonic power (P) was highly significant in reducing burrs with a contribution of 52.45%. Conversely, the surface roughness (Ra) of the drill holes decreased at 3000 rpm, and this was attributed to the brittle fracture of the fibers at a lower temperature. Both N (30.88%) and f (30.83%) had an equal influence on producing a better surface finish in the drill holes. Furthermore, the predicted optimal settings were used to validate the results and were found to be within 95% confidence and prediction interval. Finally, the microscopic images of tool wear, burr formation, and drill hole surface morphology were analyzed and examined.

Ultrasonic Electrodeposition of Cu–SiC Electrodes for EDM

Cu-SiC composite electrodes composed of both a Cu matrix and dispersed inert SiC particles were fabricated for electrical discharge machining (EDM) using the ultrasonic-aided electrodeposition technique. The influence of ultrasonic power on the surface morphology, content of SiC particles, and EDM wear rate of the fabricated Cu-SiC composite electrode were investigated. Results show that the incorporation of SiC particles into the composite electrode was enhanced and that the uniformity of particle distribution in the Cu matrix improved when the ultrasonic dispersion was initiated during electrodeposition. The composite that was generated at low ultrasonic power contained more SiC than that produced at high ultrasonic power. Moreover, the Cu-SiC electrode fabricated at low ultrasonic power displayed the least erosion wear during EDM.

Effect of ultrasound treatment on oil recovery from soybean gum by using phospholipase C

Abstract Comparative studies of enzymatic oil recovery process of water degummed soybean gum (WDSG) were carried out in mechanical-stirring (MS) and ultrasonic-assisted mechanical-stirring (UAMS) systems. The influences of ultrasonic power (0.68–1.52 W/cm 3 ), gum/water ratio (w/w) (1/0.5–1/3.0), reaction temperature (40–65 °C), enzyme dosage (200–1000 mg/kg) and reaction time (2–7 h) were investigated subsequently. A suitable ultrasonic power of 1.20 W/cm 3 was determined to guarantee satisfactory oil recovery efficiency and enzyme activity. Compared to the MS system, less time, water and enzyme dosage were required in the UAMS system for the oil recovery process, and the thermal stability of phospholipase C (PLC) under ultrasound treatment was increased. Analysis of the quality of recovered oil showed that indices including phosphorus content, free fatty acid content, peroxide value, fatty acid composition, color, smell and taste could meet the requirements of crude soybean oil. However, ultrasound treatment could accelerate the primary oxidation of recovered oil due to the effect of cavitation. These results indicate that using PLC to recover oil from WDSG with ultrasound treatment is feasible and effective, and more attention should be paid on the oxidative stability of recovered oil for its further application.

Contrast Studies of Ultrasonic Degradation Rhodamine B and Methyl Orange Dynamics

The study compared rhodamine B and methyl orange aqueous solution of sonochemical degradation kinetics, the influence of ultrasonic power, initial concentration, operating temperature on reaction rate. The experiment show that degradation reaction is free radical oxidation organic matter generated by ultrasonic cavitation, rhodamine B and methyl orange initial concentration of 0.5×10-5- 4.0×10-5 mol/L, operating temperature of 25°C - 55°C, when ultrasonic frequency of 19.6 kHz, ultrasonic power of 170-260 W. sonochemical reaction of rhodamine B and methyl orange are in line with first order reaction kinetics, and sonochemical reaction rate constant increased with increase of ultrasonic power, with increase of initial concentration decreases, the lower operating temperature; under the same experimental conditions, the rate of chemical reaction of rhodamine B sound greater than the rate of sonochemical reaction of methyl orange.

Pretreatment of heterocyclic pesticide wastewater using ultrasonic/ozone combined process

Abstract Ultrasonic/O 3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe diameter, initial pH and O 3 dosage on the COD removal were studied. The results showed that the ultrasonic/O 3 process significantly improved the biodegradability and reduced the biological toxicity of the wastewater. The ratio of BOD 5/COD was increased from 0.03 to 0.55 and the EC 50 increased from 11% to 52% under ultrasonic/O 3 treatment. Low ultrasonic frequency brought better COD removal. Initial pH was found to have a high influence on the COD removal and alkaline conditions were more favorable. The influences of ultrasonic power and probe diameter were small. With an increase in O 3 dosage, COD removal was effectively improved. The optimal operational parameters for the combined process on COD removal were ultrasonic frequency 20 kHz, initial pH 9.00, ultrasonic power 300 W and dosage of O 3 454.8 mg/(L-min), under which the efficiency of COD removal reached 67.2%.

Influence of ultrasound on phenol removal by adsorption on granular activated carbon

One of the most popular means for removal of natural organic matter found in small concentration is by adsorption. Recent studies have found that ultrasound enhances adsorption properties of different adsorbents for many contaminants in aqueous solution. This work describes the results of investigation carried out to examine the adsorption process of phenol, as an organic matter indicator, both from aqueous solution and from domestic wastewater on granular activated carbon (GAC) in absence and presence of ultrasound (US). The infl uence of ultrasonic power on the oxidation of phenol was also investigated at three different densities (1.06, 1.60 and 3.20 W/ml). The effects were monitored in terms of UV-absorbance at 270 nm, TOC and COD. Reduction of UV-absorbance and TOC have been negligible with US treatment alone and the performances have been better with adsorption into GAC. However, the adsorption rate of phenol in wastewater in presence of ultrasound, for an acoustical power of 1.06 W/ml, was twice hi...

Electrodeposition of Ni–Co/Al 2O 3 composite coating by pulse reverse method under ultrasonic condition

Ni–Co/Al 2O 3 composite coating was deposited by pulse reverse current (PRC) method under ultrasonic condition. The influence of ultrasonic power on morphology, microstructure, composition, micro-hardness and residual macrostress of composite coating was investigated by means of SEM, TEM, XRF and XRD. The results indicate the composite coating deposited under ultrasonic power becomes uniform, compact and the grains become fine; the composite content of Al 2O 3 is decreased; the micro-hardness of composite coating is improved firstly, then decreased; while the residual macrostress is increased.

Influence of ultrasonic power on the structure and composition of anodizing coatings formed on Mg alloys

This paper reports the application of ultrasonic power on the anodizing of magnesium alloys. The influence of ultrasonic power at a constant frequency of 25 kHz and two various acoustic power values, 280 and 400 W, on the structure and composition of anodizing coatings formed on magnesium alloy AZ31 was investigated. Results clearly show that ultrasound enhances the growth rate of anodic coatings and plays a very important role in the formation of coating structure and the distribution of coating composition. The anodic coatings consisted of only one layer if the ultrasound field was not applied in the solution used in this work. The anodic coatings consist of two layers when the ultrasonic field was applied and the acoustic power value increases to 400 W at a constant frequency of 25 kHz. The inner layer is compact and enriched in aluminum and fluorine, moreover, its thickness is uniform. In contrast, the contents of aluminum and fluorine in the external layer are very low and its thickness is non-uniform, some areas are thick, some thin. It was noted that there are some obvious fracture sites in the inner layer and external layer although the total thickness of coating is thick. An optimal acoustic power value should exist under the ultrasound frequency of 25 kHz to avoid the layer fracture and obtain thick coatings. The anodic coatings are composed of two phases, MgO and Al 2O 3, no matter whether the ultrasound is applied or not.