1Department of Mechanical Engineering, K.S. Institute of Technology, K.R. Road, Bangalore - 560 062, Karnataka, India.
2Department of Mechanical Engineering, University Visveswaraiah College of Engineering, K.R. Circle, Bangalore - 560 001, India.
The objective of the paper is focused on the study of machinability of alumina particulate composites. The tool wear is measured after 20 minutes of metal cutting for different operating conditions such as cutting speed, feed and depth of cut in HMT CNC Lathe. The specimens were fabricated using pressure die casting with Al-6061 reinforced with alumina particles of diameter 30–50 μm varying from 5 to 15 wt%. In the cutting tests for tool wear mechanisms, coated carbide is inserted in a tool holder of 6° rake angle and 95° approach angle was used. In the cutting tests for correlation between tool wear and percentage of alumina in the metal matrix composites (MMCs), coated carbide is inserted in a tool holder of 8° rake angle, 45° approach angle and 0° inclination angle were used. The tool wear measurements were performed on an olympus measuring microscope with a resolution of 0.0001 mm. The results from machining MMCs with conventional tools show that the main mechanism of tool wear includes two-body abrasion and three-body abrasion. A more flexible method that can be considered as a cost-saving technique is therefore sought for studying the machinability characteristics of these materials. The result shows the critical weight percentage of reinforcement is a function of the densities of the reinforcement, the matrix, the length of the reinforcement and the radius of the tool cutting edge.
aluminium, alumina, machinability, abrasion, tool wear
