Initial Damage Mechanism and Running-In Behaviour of Phosphate Conversion Coatings

2016 ◽  
Vol 721 ◽  
pp. 356-361 ◽  
Author(s):  
Andreas Nevosad ◽  
Saranya Azhaarudeen ◽  
Nicole Doerr ◽  
Heike Zacharias ◽  
Jürgen Klarner ◽  
...  

This work is focused on the damage and wear mechanisms of phosphate conversion coatings which were deposited onto steel substrates by a wet-chemical process. For studying the damage mechanism, sets of multiple scratches were performed. Scratch tests along with SEM micrographs revealed the early damage mechanisms as well as the running-in friction and wear behaviour of phosphate conversion coatings. The deeper understanding allows to increase tribological performance in terms of controlled friction and wear resistance of technical components. This way, promising measures in reduction of seizing and increase of lifetime for such components could be developed.

2011 ◽  
Vol 312-315 ◽  
pp. 1004-1009 ◽  
Author(s):  
Erdem Atar ◽  
E.S. Kayali ◽  
Huseyin Cimenoglu

This study focuses on tribological performance of as-received and borided Ti6Al4V alloys against ceramic counterfaces (Al2O3 and Si3N4 balls) in water. The wear mode of the alloy changed from ploughing to polishing by achieving a remarkable reduction in wear loss upon boriding. On the borided surface, the destructive action of the Si3N4 ball was very limited, when compared to that of the Al2O3 ball.


Author(s):  
Waleed Al-Sallami ◽  
Pourya Parsaeian ◽  
Abdel Dorgham ◽  
Anne Neville

Trihexyltetradecylphosphonium bis(2-ethylhexyl)phosphate (phosphonium phosphate) ionic liquid is soluble in non-polar lubricants. It has been proposed as an effective anti-wear additive comparable to zinc dialkyldithiophosphate. Previously, phosphonium phosphate has shown a better anti-wear performance under some conditions such as high temperature. In this work, the tribological performance and the lubrication mechanism of phosphonium phosphate are compared with that of zinc dialkyldithiophosphate when lubricating silicon under various tribological conditions. This can lead to an understanding of the reasons behind the superior anti-wear performance of phosphonium phosphate under some conditions. A micro-scale study is conducted using a nanotribometer. The results show that both additives lead to a considerable reduction in both friction and wear coefficients. The reduction in the wear coefficient is mainly controlled by the formation of the tribofilm on the rubbing surfaces. Zinc dialkyldithiophosphate can create a thicker tribofilm, which results in a better anti-wear performance. However, the formation of a thicker film will lead to a faster depletion and thus phosphonium phosphate can provide better anti-wear performance when the depletion of zinc dialkyldithiophosphate starts.


Author(s):  
Tehreem Naveed ◽  
Rehan Zahid ◽  
Riaz Ahmad Mufti ◽  
Muhammad Waqas ◽  
Muhammad Talha Hanif

All the moving components in an internal combustion engine require a lubricant that allows smooth sliding and/or rolling of interacting surfaces. Lubricant not only minimizes the friction and wear but also dissipates the heat generated due to friction and removes debris from the area of contact. Environmental concerns, decreasing mineral oil reserves and difficult disposal of nonbiodegradable conventional lubricants have urged the researchers to shift towards environmental-friendly lubricants. Number of tribological studies carried out in the past have proved that ionic liquid-based bio-lubricants are sustainable and biodegradable alternative to mineral oils. This paper presents a brief review of properties of ionic liquids and their ability to reduce friction and wear between the interacting surfaces. Tribological performance and compatibility of ionic liquids with various base-oils have been compared under boundary lubrication. The results reveal that phosphonium-based ionic liquids namely tetra-decyl tri-hexyl phosphonium bis(2,4,4-trimethylpentyl) phosphinate (P66614)i(C8)2PO2 and tri-hexyl tetra-decyl phosphonium bis(2-ethylhexyl) phosphate (P-DEHP) are more suitable for tribological applications. Since, ionic liquids can be tailored according to the application and millions of combinations are possible therefore, there is a need to summarize the published data in a more systematic and logical way.


Wear ◽  
1973 ◽  
Vol 24 (3) ◽  
pp. 261-278 ◽  
Author(s):  
D.S. Lin ◽  
F.H. Stott ◽  
G.C. Wood ◽  
K.W. Wright ◽  
J.H. Allen

Author(s):  
Jihun An ◽  
Byoung-Hyun Kang ◽  
Byoung-Ho Choi ◽  
Hyoung-Jun Kim

Poly(methylmethacrylate) (PMMA) is one of popular engineering polymers for many engineering applications such as glass substitutes, medical applications, electronic goods, optical fibers, laser disk optical media and so on. PMMA is a lightweight material with excellent optical properties and balanced mechanical properties. However, PMMA is commonly blended with various functional fillers, and rubber particles are one of them to improve the low impact toughness of unfilled PMMA comparing with other engineering polymers such as polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS) copolymer and so on. PMMA is generally used to make exterior of a commercial product, so scratch characteristics of PMMA is very important in terms of the aesthetic point of view. In this paper, rubber toughened PMMA plates are prepared by injection molding, and static and progressive scratch tests are performed. Samples are prepared by various injection molding conditions, and two orientations (machine direction and transverse direction) of the injection molded plate are considered for scratch tests. Three scratch damage mechanism stages, i.e. mar/ploughing, whitening and cutting stages, are identified by observing the scratch damages and two critical loads to define the variation of scratch damage mechanisms are recorded to evaluate the scratch resistance of rubber toughened PMMA samples. Scratch damage characteristics are examined by various microscopy techniques such as optical microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, optical profiler and so on. It is clearly observed that scratch damage characteristics of rubber toughened PMMA are changed sensitively for various test conditions due to rubber particles, so it can be known that the mold design should be carefully optimized to improve scratch characteristics of injection molded rubber toughened PMMA product.


2018 ◽  
Vol 33 (6) ◽  
pp. 828-850 ◽  
Author(s):  
R Vinayagamoorthy

The dominance of fibre-reinforced plastics in industries has enhanced the need for research to develop new composites and assess their properties. Among the various property analyses, tribological characteristics of the composites help to understand the friction and wear behaviour. This article presents a comprehensive survey on the tribological behaviour of polymeric composites, which includes the influence of various working parameters such as the velocity of sliding, sliding distance, pressure applied and temperature on the friction and wear. The article also addresses about the importance of the composite constituents such as fibre composition, fibre geometry and fibre orientation on the tribological behaviour. The major reasons causing the tribological failure like the debonding between the fibre and the matrix, failure of the matrix and the fibre are also extensively addressed. This review would be an insight to the industries and tribology researchers towards achieving optimum design for the components made of polymers.


Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1169
Author(s):  
Vladislav Tarbokov ◽  
Sergey Pavlov ◽  
Egor Smolyanskiy ◽  
Vladimir Uglov ◽  
Mikhail Slobodyan ◽  
...  

The paper presents the effect of irradiation of 321 steel substrates with a high-intense pulsed ion beam (HIPIB) on changes in functional properties of the surface layers and tribological characteristics of AlN coatings subsequently deposited above by the reactive magnetron sputtering method. The morphology of the modified surface layers, their microhardness and free surface energy levels are presented for different HIPIB energy densities. HIPIB irradiation of the substrates caused variations in the results of scratch tests combined with the acoustic emission signal processing. Their analysis has enabled concluding that the crack initiation threshold could be at least doubled for the studied coating/substrate system due to preliminary HIPIB irradiation. Finally, the obtained data were discussed, and future research directions were proposed.


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