Evaluation of four commercially produced surface treatments

The paper reports the results of characterization of four commercial surfac e treatments on M2 tool steel substrates. The treatments characterized were (a) TiN deposited by physical vapor deposition (PVD), (b) TiCN/TiN multila yer also deposited by PVD, (c) diamond-like carbon (DLC) deposited by an io n-assisted technique, and (d) vanadium carbide (VC) produced by a thermal d iffusion process. The surface treatments were evaluated for characteristics relevant to their tribological performance, such as thickness, roughness, chemical composition, micro- and nanohardness, coating-substrate adhesion, and wear resistance. In addition, a hardness model developed at the Univers ity of Newcastle upon Tyne (United Kingdom) to correct for substrate effect s was successfully applied. Nanohardness tests also yielded the elastic mod ulus values of the surface treatments, while scratch testing used for deter mining coating-substrate adhesion provided qualitative information on their ductility.