Experimental Study On High-Power Ultrasonic Machining

Engineering ceramics have excellent physical and chemical properties, such as high temperature, corrosion resistance and high hardness. Ultrasonic machining affected little by the electrical and chemical characteristics of the work piece is a good way of processing this type of hard and brittle materials. At present, the domestic ultrasonic machining power usually ranges from tens of watts to several hundred watts and its material removal rate is low, General1～5mm3/min. But its processing efficiency is low for larger parts using ultrasonic processing. In recent years, the progress of high-power piezoelectric ceramic ultrasound transducer paved the way for the high-power ultrasonic machining.The nonlinear finite element program ANSYS/LS-DYNA was used to simulate the process of ultrasonic machining. The study subjects of this simulation were boron carbide grits and the glass panel, this paper has simulated the process of single spherical, cubical, cuneal, cone-shaped abrasive and combination of kinds of abrasive impacting and rotary impacting the glass panel respectively. Material removal ways, development of cracks, stress and structure distortion of the work piece and the influence of processing parameters on the MRR were analyzed intuitively through the simulation results. To some extent, it can verify visually the existing theoretical analysis on ultrasonic machining mechanism and guide experimental study more dionally.In this paper, a series of process experiments and analysis were done using the high-power ultrasonic machining, the completed work was as follows:(1) The four factors, that is type of abrasive A、abrasive strength B、force C, were selected for the single-factor ultrasonic machining experiment. The processing efficiency (material removal rate) curve was obtained under the various factors;(2) To Select abrasive type A, abrasive strength B, force C of these three factors, each factor is divided into five levels, Power1and Power2file two sets of ultrasonic machining test, test for the five levels of the three factors is posttest, and the test data were analyzed;(3) Select Abrasive Type A, abrasive strength B, force C of these three factors, each factor is divided into five levels, a group of ultrasonic machining test, the test data analysis, and a comparison made before the test;(4) To do some analysis of the ultrasound done earlier nesting processing and the cylindrical tool head ultrasonic machining the work piece surface quality, mainly two aspects, cracks and fragmentation, on the other hand, the surface roughness;Conclusions were drew through series of experiments and analyzes as follows:(1) The high-power ultrasonic machining material removal rate was indeed much higher than the average low-power ultrasonic machining. In this experiment, the maximum material removal rate was more than600mm3/min;(2) The material removal rate in Ultrasonic machining was much higher than conventional low-power Ultrasonic machining. When ultrasound processing was required in some parts of special shapes of hard and brittle materials, shape of the tool head could be designed, resulting in higher production efficiency;(3) In terms of high power Ultrasonic machining surface quality, cracks and fragments under the influence of the force was relatively large. When forces exceed a certain threshold, lager value resulted to more serious fragmentation and larger cracks. In the same circumstances, cracks and fragmentation generated by the ultrasonic nesting tool head processing was more serious than cylindrical tool head. On the other hand, the surface roughness impact was large, abrasive finer, more likely to get a smaller surface roughness value.