Duplex surface treatment of high strength Timetal 550 alloy towards high load-bearing capacity

In the present investigation, novel duplex systems combining nickel diffusi on (DLC) deep case hardening with low friction wear resistant TiN and diamo nd-like carbon (DLC) coatings have been designed and applied to high streng th Timetal 550 titanium alloy. The load bearing capacity of the duplex trea ted Timetal 550 was assessed dynamically using both a scratch tester and an Amsler tribometer with a block-on-wheel configuration. Experimental result s showed that the load bearing capacity of these low friction wear resistan t coatings can be improved dramatically when deposited on ND-treated Timeta l 550 substrate relative to material coated with TiN and DLC alone. It was also found that the DLC/ND duplex system possessed superior load bearing ca pacity to the TiN/ND duplex system. (C) 2001 Elsevier Science B.V. All righ ts reserved.