Study on mechanisms of tool wear in turning a high strength wear resisting aluminum bronze

摘要

The difficulty in machining parts make of high strength wear resisting materials is a drag in the manufacturing process. To understand the tool wear mechanism can not only improve the tool life and efficiency but also ensure the surface quality of parts. In this study tool wear and wear mechanisms were studied by turning of a newly developed high strength wear resisting Cu-10Al-4Fe-2Ni-2Mn bronze, which has a tensile strength (σ{sub}b) of 633 N/mm{sup}2, elongation (δ) of 18 percent, Brinell hardness (HB) of 169 kg/mm{sup}2. Commercially available M2 high speed steel, and YW1 cemented carbide tools were used to turn cylindrical workpiece made of the above mentioned nickel aluminum bronze without coolant and lubricant at speed of 54.25 m/min and 35.00 m/min. Diffusion couples made of tool materials and workpiece materials were prepared by cast method. The diffusion behavior between the tool and workpiece materials of diffusion couples annealed at 900°C was studied. Scanning electron microscope and optical microscope were used for morphological study at and near the tool/workpiece interface. Electron probe microanalysis was used for composition measurement to study the inter-diffusion of elements between the workpiece and the tool. Under the turning condition of this study major tool wear mechanisms for turning KK aluminum bronze using high-speed steel tool are diffusion wear and adhesive wear. Crater was found on the rake and wear band was found on the flank. Major tool wear mechanisms for turning aluminum bronze using YW1 cemented carbide tool are diffusion wear, attrition wear, sliding wear and micro-chipping at the cutting edge. No Crater and wear band were found on the rake and the flank, respectively. Strong inter-diffusion of elements was observed in both diffusion couples and turning tools. Results obtained from this study indicated that diffusion play a vital role in the tool wear.