Feasibility Study of Using TiCN and CrN Thin Film Coatings to Enhance Lifetime of Grippers Used in Hard Disk Drive Assembly Line

This work investigates the use of TiCN and CrN thin film coatings to increase the lifetime of high precision grippers used for aligning a slider in hard disk drive manufacture. Experimental study to characterize wear performance and properties of the coatings and finite element analysis of the coated grippers were carried out. The macro micro scale FE models of the coated grippers which take into account the surface profile were developed in order to calculate contact stresses and in-service sliding distance. Wear depth and lifetime of the coated grippers were then estimated using a classic Archard wear equation. It was found that the lifetime can increase greatly with the use of coatings, e.g. 10 times using TiCN coating and 20 times using CrN coating. Life improvement can also be achieved with some control of the slider initial position before making contact with the grippers.