Properties of Wear-Resistant MoN Films on Microengineered Substrates

Abstract

Molybdenum nitride layers were deposited onto the substrates of high-speed steel using high-power impulse magnetron sputtering. To control the tribological properties of these wear-resistant surfaces, a sophisticated pretreatment of the substrates was performed. Both the topography and the composition of the surfaces were modified on a length scale of a few micrometers before the deposition of MoN. For that purpose, a microembossing technique was applied that used specifically prepared diamond stamps. Compositional variations are realized by an additional deposition of silver. Modifying the properties of the wear-resistant surface via this substrate engineering method allowed a significant reduction in the coefficient of friction, a change of the dominant wear process and a possible lifetime increase. Changing the surface topography led to a reduction of friction and, therefore, to reduced mechanical work supplied to the surface. Occurring wear was reduced accordingly. The introduction of silver further reduced the mechanical energy that was available for the abrasion process and led to an additional increase in the lifetime of the surface. It was concluded that not only the wear volume, but also the relevant wear mechanisms could be influenced via a substrate modification.

The Behavior of TiAlN and TiAlCrSiN Films in Abrasive and Adhesive Tribological Contacts

“…In all cases, iron oxide particles are found provided by the counter body and oxidized during wear testing. Note, that this is consistent with results obtained on MoN surfaces [30]. The interfaces between the counter body and abrasion particles are identical for the considered surfaces and thus cannot be the origin of the change in the tribological properties of the contact.…”

“…In all cases, iron oxide particles are found provided by the counter body and oxidized during wear testing. Note, that this is consistent with results obtained on MoN surfaces [30]. The interfaces between Both curves basically show the same frequency dependence: a monotonous decrease in the wear volume with the increasing frequency.…”

“…In many cases the introduction of surface structures on a microscale leads to significantly reduced friction and wear. A remaining question is whether the compositional or topographical modification is the method of choice to reduce friction and wear in particular contacts or if both concepts might be combined [30].…”