Study On The Ultrasonic Assisted Grinding Processing Technology Of SiCp/Al Composite

SiCp/Al composite is a stiff particle-reinforced metal matrix composite, of which aluminum alloy is used as the metal matrix and SiC particles are the reinforced phase. With the advantages such as high conductivity, high thermal conductivity, specific strength and specific rigidity, small linear expansibility, good dimension stability and heat resistance, good fatigue performance and low price, etc., SiCp/Al has been widely used in industries such as aviation, automobiles, electronic packaging, astronomy and optics.Due to high strength hard and brittle SiC ceramic grain being added, this material has been improved in mechanical properties and is seen to possess isotropic properties under macrography. However, owning to the SiC particle reinforcement, many difficulties are found in machining the material such as heavy tool abrasion, larger cutting force, BUE and high cutting temperature, which make the tool life shorten. In addition, material removal mechanism of SiCp/Al composite is different from ordinary metal materials and it is difficult to ensure good surface quality and machining precision by traditional surface processing. With the increasing of the SiC volume fraction in SiCp/Al composites, machining is one of the major problems that resists its wide spread engineering application.To solve the machining problems of SiCp/Al composite, an ultrasonic assisted grinding system was developed in this paper. Some researches were carried out about processing performance of the ultrasonic assisted grinding of materials. The main work and results are as follows:1. The ultrasonic assisted grinding test platform was set up. According to the test requirements and the conditions of processing, the ultrasonic generator and the ultrasonic structure devices were designed. Based on self-designed vertical drilling and milling machine, ultrasonic devices and three-dimensional dynamometer were installed to complete the preparation for the experiments.2. This paper researches on the contrast experiments between ultrasonic assisted grinding and traditional grinding about the grinding force. The influence of grinding parameters such as grinding force, spindle speed, feed rate and grinding depth on the grinding force were obtained. Compared with the traditional method, the grinding force could be reduced by50%at most in the ultrasonic machining.3. This paper also presented a study of the surface qualification of ultrasonic assisted grinding and common grinding. By observing surface morphology and testing the surface roughness, it could be seen that the surface qualification of SiCp/Al by ultrasonic grinding was worse than that by common grinding.4. According to the characteristics of SiCp/Al composite, the paper contains a research on the SiCp/Al composite subsurface damages testing method. Through the research on the subsurface damages of SiCp/Al machined by ultrasonic grinding, the reason that the SiCp/Al surface roughness by ultrasonic is worse than that by common grinding was found. After all the researches, the paper presented the processing mechanism of ultrasonic assisted grinding SiCp/Al composite.