Sumitomo Electric Hardmetal aims ACE-Coat AC830P inserts at heavy duty rough turning

Sumitomo's ACE-Coat AC830P turning inserts combine its Super FF coating with a GE-Type chipbreaker style able to reduce the likelihood of damage to the rake face of the insert under very heavy duty rough turning applications. The Sumitomo GE-Type chipbreaker is designed to reduce crater wear which enhances the levels of stability and predictability under difficult machining scenarios. This is achieved by spreading the loading from the applied cut on the insert across the chipbreaker rather than being concentrated within one small area. This lowers the stress levels generated by the cutting action and, as a result, overcomes the main cause of wear during high efficiency fast feed/higher speed machining. In addition, further control of chip flow is achieved by a primary ridge on the top of the insert and a separate ridge to the side which reduces any stress concentration and possible damage to the rake face. The development of AC830P insert has also focused on the optimisation of the substrate and the sintering process to achieve an improvement in the level of indexing accuracy. When conventional inserts are produced to meet heavier duty machining tasks up to 10% cobalt tends to be added to the sintered mix which can not only have a negative influence on index accuracy but can also affect the ultimate clamping power of the tool holder, explains Sumitomo. The Sumitomo Super FF chemical vapour deposition (CVD) multi-layer coating of titanium carbonitride and aluminium oxide is some 8 microns thick form a dense and homogenous ceramic film structure. The resulting ultra-smooth finish achieved aids chip flow, improves the shape of the chip and its exit direction from the cutting zone. Sumitomo ACE-Coat AC830P turning inserts are available in positive, negative and double-sided formats and in triangular, diamond, square and trigon versions. Applied cutting speeds in low carbon steel can be between 100 to 250 m/min and 90 to 200 m/min in carbon/alloy steels over 180 HB. Depth-of-cut can be accommodated between 1 and 5 mm and feedrates applied between 0.25 to 0.6 mm/rev.