Wear performance of duplex treated low alloyed steel against wood (beech) as static partner

The sliding tribological behaviour of Cr-(WC-Co) coating against wood (beech) as counterpart was investigated using a duplex treatment of low carbon steel(DIN 18CrMo4). The duplex treatment consists of LPC (low pressure carburising) + R.F magnetron co-sputtering of Cr and WC-Co. Pin-on-disk configurations in dry condition wear tests were performed. The wear scars of the coatings were evaluated using optical profilometry, scanning electron microscopy (SEM/EDS) and the wear mechanisms were consequently discussed. The aim of this work is to study wear mechanisms on the wood pin/disc couple. It was concluded that best behaviour was observed in the case of higher Cr content coating

Sliding wear behavior of magnetron sputtered chromium carbide thin films

Purpose – The purpose of this technical paper is to investigate the friction and wear behavior of inexpensive and durable cutting tools, developed for wood machining using duplex treatment. Design/methodology/approach – Cr–(WC–Co) coatings were eposited onto carburized low-alloy steel substrate by a reactive magnetron sputtering. The total coating thickness was approximately 2 m. Unlubricated wear tests have been performed using a disc sample sliding against an alumina ball (Al2O3) and a wood (beech) pin. Findings – The paper provides information about the effect of duplex reatment on the surface properties of low-alloy steel against wood and offers practical help for the researchers in coating topic. Originality/value – Experimental results showed that sliding wear properties of the selected coatings are strongly dependent on the counter-face material. When tested against alumina balls, the wear mechanisms are oxidative wear followed by a combination of adhesive and abrasive wear, while a combination of an oxidative and adhesive wear was the main wear mechanism observed against a wood pin.Ministère algérie

Corrosion and Wear performances analysis of PVD CrMoN/Cr Coatings

Tools coated CrN based alloys are currently used in several industries for machining and manufacturing, but present severe wear, limiting their service life. Seeking an alternative, three CrMoN monolayers (~1µm in thickness) coatings with varying in the Mo percentage content were elaborated using the RF magnetron co-sputtering method. These coatings were evaluated and compared with the alloy currently used (CrN) by electrochemical tests in NaCl solution (stationary and no stationary method) and sliding wear tests (ball-on-disc configuration) performed at room temperature. The results indicate that the samples coated with CrMoN presented better performance against wear and corrosion than the uncoated sample. Among the coatings, the labeled C1 (27 % Mo) showed the best corrosion resistance as it presents a positive corrosion potential Ecorr. However, the best wear resistance (lowest coefficient of friction) was shown by coating labeled C4 (33 % Mo). All of the tested specimens underwent abrasive wear in addition to adhesive wear

Synthesis and tribocorrosion performances of multilayer (Ta/ZrN)n coatings

Multilayer thin coatings (~3 µm in thickness) were deposited using reactive radio frequency magnetron sputtering on Ti-6Al-4 V substrate for biomaterial applications. Films are a combination of hard zirconium nitride with pure tantalum, used to manage interfacial stress and to avoid crack growth. Alternating hard/ductile material is a biomimetic design inspired by nature (nacre-inspired materials). Tribocorrosion tests were performed in Hank’s solution at 37 ◦◦C, under open circuit potential by using a ball-on-disk reciprocating tribometer. A tendency to high resistance against corrosion was found for all the samples. Coatings with a top 100 nm thick ZrN layer showed more noble potential as well as a reduction of both the friction coefficient and the wear rate during the sliding phase. The principal wear mechanism is related to a tribocorrosion layer formation

Tribological and electrochemical performances of Cr/CrN and Cr/CrN/CrAlN multilayer coatings deposited by RF magnetron sputtering

CrN/CrAlN and Cr/CrN/CrAlN multilayers were grown with dual RF magnetron sputtering. The application of these multilayers will be wood machining of green wood. That is why ball-on-disc and electrochemical tests in NaCl aqueous solution were realized to elucidate the tribological and corrosion behavior of these coatings as they will be exposed to wear and corrosion during wood machining process. The samples/alumina and samples/WC coupling showed different wear mechanisms. The 300 nm thick Cr/CrN/CrAlN multilayer demonstrated the best tribological behavior and corrosion resistance. The influence of growth defects on corrosion resistance has been shown

Surface performances of PVD ZrN coatings in biological environments

Zirconium nitride (ZrN) thin films were deposited by reactive RF magnetron sputtering on Ti-6Al-4V and Si (100) substrates for potential use in biomedical applications. The tribological behaviour was evaluated against bovine bone in dry condition using a pin-on-disc apparatus. Abrasion is the primary wear mechanism observed in ZrN/bone contact. The corrosion properties were determined through two electrochemical techniques: potentiodynamic polarization and electrochemical impedance spectroscopy. The coatings with reduced oxygen content provided: (i) good resistance against corrosion when exposed to physiological solution and (ii) better anti-bioadhesion against Staphylococcus aureus bacteria.Bourse PNE Ministère algérie

Dry sliding wear investigation on tungsten carbide particles reinforced iron matrix composites

WCparticles reinforced Fe-based metal matrix composites were synthesized by powder metallurgy process. The microstructure and composition of the specimens were analyzed and the wear-resistant properties againstWCand alumina balls were comparatively investigated by SEM/EDS analyses. The wear rates of specimens were evaluated by optical profilometry. Microstructure exhibited austenite Fe-FCC dendrites, eutectic (iron austenite + carbides) and primary carbides. Two wear mechanisms have been identified from SEM as main mechanisms during dry sliding wear of Tungsten carbides reinforced iron matrix, namely oxidation and abrasion. The overall wear performance, which is obtained by considering the wear loss of the substrates, indicated less resistance against Alumina compared to WC ball contact

Mechanical properties and bio-tribological performance of PVD (Ta/ZrN)n multilayer coatings on UHMWPE in bovine serum lubrication

This work investigated the tribological performance of (Ta/ZrN)n multilayer coatings against ultrahigh molecular weight polyethylene (UHMWPE) material. Three multilayer coatings with different designs were deposited on Ti-6Al-4 V substrate and subjected to wear testing under lubrication of diluted bovine calf serum. The results revealed an improvement in wear resistance of (Ta/ZrN)n multilayer coatings and low coefficient of friction under an applied load of 1 N. High hardness, excellent biotribological properties, and low residual stresses were obtained in the multilayer coating with the thinnest ZrN as the topmost layer of 100 nm. This work demonstrates that Ta/ZrN multilayers can be promising coatings for prosthesis applications

Wear and Corrosion Resistance of CrN-based Coatings Deposited by R.F Magnetron Sputtering

International audienceA comparative study was conducted to evaluate the performances against wear and corrosion of CrN, CrMoN, CrZrN, CrVN single layer thin films. The latest are synthesized onto steel substrates (DIN 90CrMoV8), using R.F reactive magnetron co-sputtering. The experimental work was achieved using ball-on-disc configuration in dry conditions against WC balls. The main conclusions are: (i) electrochemical tests in 0.3 wt.% NaCl solution indicated that CrZrN are improved anticorrosion performance when compared to CrN, while CrMoN demonstrated a poor corrosion resistance;(ii) the CrN coating presents the better tribological properties when compared to the ternary nitride coatings

Wear and Corrosion Resistance of CrN-based Coatings Deposited by R.F Magnetron Sputtering

A comparative study was conducted to evaluate the performances against wear and corrosion of CrN, CrMoN, CrZrN, CrVN single layer thin films. The latest are synthesized onto steel substrates (DIN 90CrMoV8), using R.F reactive magnetron co-sputtering. The experimental work was achieved using ball-on-disc configuration in dry conditions against WC balls. The main conclusions are: (i) electrochemical tests in 0.3 wt.% NaCl solution indicated that CrZrN are improved anticorrosion performance when compared to CrN, while CrMoN demonstrated a poor corrosion resistance;(ii) the CrN coating presents the better tribological properties when compared to the ternary nitride coatings