Papers by Keyword: Ultrasonic Grinding

Abstract: The drilling of microholes in hard and brittle materials by ultrasonic grinding was carried out using polycrystalline diamond (PCD) micropins fabricated by electrical discharge machining. They can be employed as micro-grinding tools because the convex parts of discharge craters formed on the tool surface can serve as cutting edges of abrasive grains in grinding wheels. In the drilling of crown glass, the increase in the grinding force and the generation of cracks and chippings at hole edges were suppressed owing to the high wear resistance of PCD. Under suitable conditions, drilling was also successfully performed in silicon, which is apt to exhibit cracks and chippings at hole edges.

Abstract: High volume fraction SiCp/Al composites were grinded in rotary ultrasonic vibration aided grinding in this experiment, exploring the effects of different grinding parameters (grinding depth, grinding wheel speed, feed rate) on grinding force and the material removal mechanism with ultrasonic grinding. The results showed that grinding force of ultrasonic grinding is lower than the ordinary grinding in the same grinding parameters. Studying on material removal mechanism of ultrasonic vibration grinding is bound to have important theoretical and practical significance for the improvement of grinding processes and the development of mechanical according to the advantages of grinding and ultrasonic machining. Keywords: High volume fraction SiCp/Al composites; ultrasonic grinding; grinding force

Abstract: Analyzed the relationship between electrical parameters of the ultrasonic and electrolytic in-process dressing (ELID) composite grinding and the surface quality of the ceramic through the experiment. The value of the voltage and the current were recored by labview and the surface quality of the ceramic was tested using Talysurf CCI 6000 In the experiment. The results show that the selection of electrical parameters affects the electrolysis speed of diamond grinding wheel and the speed of the oxide film formed and the quality of the oxide film, and then affects the grinding performance of the grinding wheel and the grinding quality of workpiece.

Abstract: The ultrasonic-assisted single-grit grinding device is designed which can be used to efficiently simulate grinding process, and the comparative tests of single-grit ultrasonic grinding are carried out between Nano-ZrO₂ ceramics and ZTA ceramics under different grinding depth. The experimental results show that the bigger the scratch depth was, the greater damage degree of material was, nano-ZrO₂ ceramics’ grooves is smoother than that of ZTA ceramics and the damage of its material is minor; ultrasonic vibration broadens the range of plastic cutting of Nano-ZrO₂ ceramics in some degree. The experimental phenomena also show that the rolling role of abrasive particle can be conducive to material plastic deformation.

Abstract: In this work, grinding test was performed in terms of machining parameters, such as grinding speed, feed rate, etc., in order to study effect of ultrasonic vibration in grinding. The design of experiment (DOE) approach was used for an optimal condition of ultrasonic assisted grinding, which can minimize the grinding forces. In DOE, ultrasonic amplitude power, feed rate, and rotation speed of spindle were chosen as the major machining factors. The grinding forces were measured and compared between the conventional grinding and ultrasonic assisted grinding. From the experiment, it was found that the grinding forces decreased as the ultrasonic vibration power and the rotation speed of spindle increased while the grinding force was reduced as the feed rate increased. In addition, regression model was formulated for obtaining optimal grinding condition.

Abstract: In this paper, a ultrasonic horn, which can vibrate longitudinally with a frequency of 20㎑, was designed using finite element method (FEM). And the ultrasonic horn was fabricated for ultrasonic assisted grinding. To evaluate machining performance of the fabricated ultrasonic horn, grinding test was conducted on alumina ceramic (Al2O3). In the grinding test, grinding forces was measured and compared between the conventional grinding and the ultrasonic assisted grinding. The results showed that the grinding force in the ultrasonic grinding was lowered than the conventional grindign by 3~20%.

Abstract: In this paper, the sand vibration test of the ultrasonic wave is done under ultrasonic vibration grinding. In this test, the "skin effect"is observed when the ultrasonic waves pass to the nano-ceramic plate, which is amplified by the ultrasonic horn. This phenomenon is analyzed by the second-order surface wave theory and the waves which pass to the workpiece are surface waves generated. These explain the good grinding surface quality and high efficiency under the two-dimensional ultrasonic grinding in the same conditions.

Abstract: The surface residual stress of nano-composite ceramics prepared by mixed coherence system and machined both in ordinary grinding(OG) and ultrasonic vibration grinding(TDUVG) respectively were described. Researches showed that the characteristics of residual stress on ceramic surface is affected by grinding load, ultrasonic vibration frequency and released stress induced by generation of cracks whose magnitude is affected by material removal mechanism. Whether in ordinary grinding or ultrasonic grinding, tangential residual stress (TRS) in X direction is tensile stress, and in Y direction is compressive stress. The surface residual tensile stress in ordinary grinding is larger than that in ultrasonic grinding with the same grinding conditions. The influences of multi-frequency on the residual stress are studied.

Abstract: The surface roughness of nano-composite ceramics machined by means of multi-frequency ultrasonic vibration grinding was investigated with the diamond grinding wheel dressed by elliptical vibration. The results indicate that the surface roughness is influenced by ultrasonic vibration frequency, feeding speed, grinding depth. The ultrasonic vibration frequency and the grinding depth are not the higher the better and there are suitable values. The surface roughness gets worse with the increase of feeding speed.

Abstract: This paper proposes to use a method of ultrasonic milling on the composite materials processing, we mainly studies the effect of the length of the tool rod, tool rod diameter on the acoustic resonant frequency, amplitude, to ensure processing quality and improving the tool's vibration effect.