Abstract
In the present paper, residual stresses and adhesion energies of DLC films were measured and discussed. DLC films consist of Cr/C gradient interlayer and a-C:H layer were deposited by UBM sputtering. Residual stresses of these films were calculated by the use of improved Stoney's equation. And adhesion energies were calculated by our contrived equation. Residual stresses increased with increasing substrate bias voltage under -300V, and decreased over -300V. And these decreased with CH_4 mixture ratio. Adhesion energies decreased with increasing substrate bias voltage. And these were increased with CH_4 mixture ratio. Residual stresses were found to be affected by hydrogen content, Ar ion assistant and substrate temperature. Adhesion energies strongly corresponded with Sp^3 fraction. Therefore, decreasing Sp^3 fraction brought the increase adhesion energy. In application of DLC films to gear tooth flanks, adhesion, hardness, and thickness of the films should be optimized, then DLC films could be expected to improve for their pitching and scuffing resistance.
