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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This paper presents an experimental study in high speed milling of SiCp/Al composites. Machining tests were carried out on a high speed milling machine by using chemical vapour deposition (CVD) diamond coated tools. The surface micro-topography was tested by the OLS3000 Confocal Laser Scanning Microscope. The Gaussian filtering method and the least square fitting method were used to treat the measured results. Two methods are compared according to the effect on keeping important original surface’s character. The results showed that the least square fitting method is suitable due to its good accordance to the original surface’s character.

Due to its relatively low mass density, low cost, high strength, the aluminum alloy is an ideal optical material to fabricate the large metal mirror of infrared band optical systems. The diamond ultra-precision cutting can produce ultra smooth machined surfaces without other finishing processes. Consequently, it can be used as a effective method to fabricate the large metal mirror. However, the tool wear is severe during the ultra-precision processes, which will ruduces the surface error of the large metal mirror. In this work, the ultra-precision cutting tests were performed to investigate the tool wear. The tool wear was examined by using a scanning electron microscope (SEM), and the chip was examined by using x-ray energy dispersive spectrdmeter (EDS). The tool wear mechanism and the influence of the chutting parameters on the tool wear were investigated. The results show that the daimond tool occurred abrasive wear and diffusing wear in the diamond ultra-precision cutting of aluminum alloy. The average clearance wear width increases with an increase of the cutting speed and the feed rate. There is a slight rise in the average clearance wear width as the depth of the cut increases in the range of 5μm-15μm. The average clearance wear width obviously increases when the depth of the cut reaches to 20μm.

The aluminum alloys are widely used to manufacture large mirror of infrared band optical systems because they have many advantages such as low cost, low mass density, well thermal conductivity, well plasticity and easy manufacturing. In order to imporve the machining efficiency and meet the requirements of suface error and suface roughness of large metal mirror, diamond ultra-precision cutting is used as finish machining to manufacture them. But the diamond tool wear is severe which is induce by the cutting heat and the cutting force during the cutting process. In this work, the metal cutting finit element sofeware-AdvantEdge has been used to study the cutting tempreture in diamond ultra-precision cutting of aluminum alloy, the influence rules of cutting parameters and tool geometric parameters are researched. And the diamond ultra-precesion cutting experiments were performed, the cutting temperature were detected by infrared thermal imager. The results show that the cutting speed exerts the most considerable influence on the cutting temperature, and the cutting temperature increases with an increase in the cutting speed. Although the temperature detected by the infrared thermal imager in the diamond ultra-precesion cutting experiments is lower than that obtained from the simulation of finit element method (FEM), the varied trend of the cutting temperature is the same. So the FEM simulation proves to be true.