The silicon carbide reinforced aluminum matrix composites (SiCp/Al) are widely used for its high specific stiffness and high specific strength. However, the poor surface quality and machined surface defects limit its further application. The aim of this paper is to investigate the effect of cutting parameters on the machined surface defects in high-speed milling of SiCp/Al composites. The tests were performed on a high precision computerized numerical control (CNC) precision milling machine using a polycrystalline diamond (PCD) tool, and the machined surfaces were measured by the scanning electron microscope (SEM).It was found that cutting parameters have a great influence on the depth of big pits. A high feed rate and a low cutting speed correspond with a big cutting force, and result in a large depth of big pits.

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The normal circular arc bevel gears are used in industrial areas of high speed, high bearing and high strength widely. A mathematical simulation model is built and it can analyze transmission error and contact zone of normal circular arc bevel gears. In this model, the instantaneous engaging points of gear pair are transformed into the least-values of rotary angles of corresponding points between two gears along the final motion, so this method is very simple and effective. Under the condition of existing helix angle error, transmission error and contact zone of a pair of normal circular arc bevel gears are simulating analyzed. At last, the operation test of contact zone of gears indicates gears transmission is stable and the gears contact zones are largely in line with the simulation results.

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SiCp/Al thin-walled structure is processed by rotary ultrasonic machining (RUM). Machining allowance of thin-walled structure is large, manufacturability is bad, and it is vulnerable to vibration to reduce processing quality in machining. Based on analysis of chatter mechanism of RUM, a dynamic model for chatter analyzing and a stability judgment criterion are established and the simulation is conducted for a typical thin-walled component of SiCp/Al composite with time domain analysis method. The simulation results show that machining parameters of RUM could be optimized selected with this model, chatter could be prevented effectively and a good processing effect achieved.