Application of Silicon Nitride Tools to High Metal Removal Rate Machining

The combination of silicon nitride tooling and high metal removal rate (HMRR) machining has demonstrated the ability to improve the productivity of cast iron machining operations by as much as 200 percent. To take full advantage of the concept, improved process optimization techniques were devised, a special high-power, high-speed chucking machine was built and several test programs, involving turning and milling, were conducted. The paper describes these developments in detail and presents laboratory and plant test results to illustrate the gains in productivity made possible by this concept.