THE NEW DIAMOND-COATED CARBIDE CUTTING TOOLS

CVD diamond sheet ( thick film, > 250 mu m) tools have been available for several years. However, commercially useful thin-film (<50 mu m th ick) diamond-coated carbide tools have been introduced only recently, indicating that long-standing technical problems related to diamond-ca rbide adhesion have been largely resolved. Improved coating adhesion l eads to more reliable and predictable performance in the cutting envir onment. Surface characteristics of the coating on the tool rake surfac e affects chip formation and on flank surfaces, the workpiece surface roughness. Diamond-coated tools can meet or exceed the tool life provi ded by conventional polycrystalline diamond tools in some applications , but typically fall short in matching workpiece finishes. Nevertheles s, diamond-coated tools are starting to play an important role in mach ining non-ferrous and non-metallic materials.