| 摘要 |
<p>The inner circumferential surface (40) of a ring (22) is coated with a DLC film (42) after a flexible stress relaxation layer (44) constituted of titanium metal is deposited on the surface (40). Due to this configuration, the stress relaxation layer (44) acts like a cushion to absorb differences in deformation between the DLC film (42), which has high rigidity, and the ring (22). Even when the ring (22) has a relatively low hardness with an HRc of 50 or less, separation of the DLC film (42) therefrom due to differences in deformation is inhibited. Since the DLC film (42) contains titanium, which is the same metal as the metal constituting the stress relaxation layer (44), a satisfactory atomic affinity is obtained at the interface. Furthermore, the incorporation of titanium reduces the internal stress of the DLC film (42) to lower the stress to be imposed on the interface, and adhesion between the stress relaxation layer (44) and the DLC film (42) is improved. This improvement in adhesion, coupled with the inhibition of separation of the DLC film (42) caused by deformation differences, improves the strength of adhesion of the DLC film (42) to the ring (22).</p> |
