Spatio-temporal behaviour of atomic-scale tribo-ceramic films in adaptive surface engineered nano-materials

Abstract

Atomic-scale, tribo-ceramic films associated with dissipative structures formation are discovered under extreme frictional conditions which trigger self-organization. For the first time, we present an actual image of meta-stable protective tribo-ceramics within thicknesses of a few atomic layers. A mullite and sapphire structure predominates in these phases. They act as thermal barriers with an amazing energy soaking/dissipating capacity. Less protective tribo-films cannot sustain in these severe conditions and rapidly wear out. Therefore, a functional hierarchy is established. The created tribo-films act in synergy, striving to better adapt themselves to external stimuli. Under a highly complex structure and non-equilibrium state, the upcoming generation of adaptive surface engineered nano-multilayer materials behaves like intelligent systems - capable of generating, with unprecedented efficiency, the necessary tribo-films to endure an increasingly severe environment.

Improvement of Wear Performance of Nano-Multilayer PVD Coatings under Dry Hard End Milling Conditions Based on Their Architectural Development

“…Therefore, the tool with better protection has a higher tool life ( Figure 9). As was shown previously [17] non-protective TiOx and …”

“…The nano-laminated coating with higher number of layers contains bigger amount of lattice defects [16]. Therefore, it possesses a higher non-equilibrium state and has enhanced catalytic features [17]. In this way formation of thermal barrier tribo-films on the friction surface could be accelerated and the wear rate is reduced.…”

“…The better ability of the 3 microns thick coating to protect its surface is also related to the formation of protective triboceramic film layer [17] (Figure 10). It was shown previously that a variety of thermal barrier tribofilms are forming on the surface of the coating under operation [16,17]. Effective replenishment of these films is strongly related to the surface damage of the coating layer.…”

“…The general idea of the surface engineered layer optimization is to create an architecture that provides adaptive spatio-temporal behavior of the coating [17]. In this way the next generation of coatings could be developed.…”

Investigation of Coated Cutting Tool Performance during Machining of Super Duplex Stainless Steels through 3D Wear Evaluations

“…Figure 4a shows the location selected for XPS studies. A possible explanation of the observed improvement on the metal flow in the case of the AlTiN coated insert versus the CVD TiCN + Al2O3 coated and uncoated tools is the formation of tribo-films on the rake surface during friction [23]. Smoother morphology of the chips (Figure 3d) during machining of SDSS using cutting tools with the AlTiN coated tool corresponds to better thermofrictional conditions during cutting.…”