Abstract
We studied the effect of compressive stress on the wear resistance of polycrystalline diamond films synthesized by hot-filament chemical vapor deposition (CVD) method using ethanol as the precursor. Samples were (a) a film coated onto a tungsten carbide substrate to give the highest compressive stress to the film, (b)∼(d) films brazed onto tungsten carbide substrates, and (e) a film glued onto a tungsten carbide substrate to make the film almost stress-free. Compressive stress in the film sample was measured by X-ray diffraction and found to range from -300 to -1500MPa depend on the sample. Films then were subjected to a wear test involving application of a rotating diamond wheel to the film surface. Results showed that the higher the compressive stress in the film, the greater the wear resistance. Film having an absolute compressive stress of ≥1000MPa, for example, showed wear resistance about three times higher than that of a stress-free diamond film or sintered diamond.
