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 thick) diamond-coated carbide tools have been introduced only recently, indicating that long-standing technical problems related to diamond-carbide adhesion have been largely resolved. Improved coating adhesion leads to more reliable and predictable performance in the cutting environment. Surface characteristics of the coating on the tool rake surface affects chip formation and on flank surfaces, the workpiece surface roughness. Diamond-coated tools can meet or exceed the tool life provided by conventional polycrystalline diamond tools in some applications, but typically fall short in matching workpiece finishes. Nevertheless, diamond-coated tools are starting to play an important role in machining non-ferrous and non-metallic materials.