THE EFFECT OF CUTTING ENVIRONMENT AND TOOL COATING WHEN HIGH SPEED BALL NOSE END MILLING TITANIUM ALLOY

摘要

Tool failure under all machining conditions irrespective of the cutting speed, cutting fluid pressure/flow rate and type of tool coating, occurred by notching at the depth of cut position. The use of the 150 bar cutting fluid environment did not produce a consistent trend in tool life when compared to 70 bar. The majority of coatings used gave similar results to the uncoated WC tool, however, the particular multilayer TiAlN product used gave a approx 50 percent improvement in performance. Unfortunately, previous work by the authors suggests that this may not be the case for all TiAlN coated products. The microstructure and microhardness of the workpiece remained largely unaffected by the high speed ball nose end milling process even when using worn tools.