Research On Precision Cutting Of Particle Reinforced Aluminum Metal Matrix Composites

Particle reinforced aluminum metal matrix composites have many excellent mechanical properties and physical properties such as high specific strength and specific stiffness, resistant wear, resistant corrosion, anti-fatigue, low thermal coefficient of expansion, low density, high micro-yield strength, resistant radiation, favorable dimensional stability and thermal conduction, etc…They will increasingly be used in many fields such as aeronautics and astronautics, weapon, automobile and electron and so on, which makes them become one of the main topics of research and development in the field of metal matrix composites. However, one of the substantial clauses that restrict extensive use of this composite is that its tool wear rate is too high and surface quality is too low in the process of cutting. Therefore, research on mechanism of cutting particle reinforced aluminum matrix composite to reduce tool wear and increase surface quality is of important.To promote the application of aluminum metal matrix composite, relative theory analysis and experiment research of tool wear and machined surface quality during cutting process are performed to the SiCp/Al and Al2O3 composites.Firstly the research of main influencing factors and influencing rules of tool wear have been executed. Tool wear cutting experiments with different types (SiC, Al2O3) and different components (reinforced particle content and particle size) of composites have been carried out using sintered-carbide, PCD, CBN. The pattern, microstructure and components of wear zone have been tested and analyzed through optical microscope and SEM etc, and the influencing degree on tool wear of tool material properties, work-piece components, cutting process parameters etc have been researched, also the main wear pattern and main causes tool wear during cutting of particle reinforced aluminum metal matrix composites have been put forward.Based on the above, precision cutting experiments of different composites are executed by PCD, and the influence of cutting parameters, tool geometric parameters and properties of work-piece on machined surface roughness has been researched, then the machined surface configuration of composites has been tested and analyzed using SEM.Finally, ultrasonic vibration cutting of particle reinforced aluminum metal matrix composites has been performed. The value of tool wear in ultrasonic vibration cutting of different work-piece has been tested and compared with the experimental results in conventional cutting; Also the influence of tool rake angle and tool nose radius on machined surface roughness in ultrasonic vibration cutting has been researched. Experimental results indicate that too wear is decreased by applying ultrasonic vibration.The above research results indicate that, the tool wear during cutting particle reinforced aluminum metal matrix composites is severe, the machinability of which is lower, and PCD is the relative ideal tool material to cutting this kind of work-piece materials. Also ultrasonic vibration cutting embodies obvious effects in promoting tool life.