Enhancement of head-disk interface durability by use of diamond-like carbon overcoats on the slider´s rails

Al₂O₃TiC sliders used in magnetic recording hard disk drives were coated with diamond-like carbon (DLC) to improve the wear durability of the head-disk interface (HDI). Both contact-start-stop and constant speed drag tests were conducted during which the build up of friction associated with wear of the thin film disks was measured in a standard disk wear tester. The friction values increased three or fourfold in the tests with uncoated sliders, whereas tests conducted with DLC coated sliders showed only a twofold increase in friction in the early part of the test followed by constant friction values afterwards. This major improvement was found for as little as 7 nm of coating on the sliders. Increases of wear durability of the head-disk interface by factors of 50-200 were obtained