scholarly journals Molecular Coverage Determines Sliding Wear Behavior of n-Octadecylphosphonic Acid Functionalized Cu–O Coated Steel Disks against Aluminum

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 280
Author(s):  
Stephan Prünte ◽  
Denis Music ◽  
Velislava L. Terziyska ◽  
Christian Mitterer ◽  
Jochen M. Schneider

The sliding wear behavior of Cu–O coated steel disks functionalized with n-octadecyl-phosphonic acids was evaluated against aluminum in ball-on-disk tribometer experiments. After 5 m of sliding the friction coefficient of the functionalized sample with maximum molecular coverage is ≤0.3 ± 0.1. Surfaces with lower coverage mitigate friction and wear as well exhibiting initially similar low friction coefficients but reveal the breakdown of lubrication for sliding distances <5 m. The length of the low friction sliding distance before breakdown scales with the coverage of n-octadecylphosphonic acids on the Cu–O surface. Coverage hence determines the tribological behavior of the functionalized surface against sliding aluminum. As the coverage is increased, detrimental asperity contacts between the rubbing surfaces are reduced.

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Géraldine Theiler ◽  
A. P. Harsha ◽  
Thomas Gradt

In the present study, the tribological behavior of polyaryletherketones (PAEKs) and their composites was investigated in air and vacuum environment. Polymer matrices were filled with either glass or carbon fibers and compared with a standard bearing material containing 10% carbon fiber (CF), 10% graphite, and 10% polytetrafluoroethylene (PTFE). The samples were tested in a pin-on-disk configuration under continuous sliding against a rotating steel disk (AISI 52100) at different sliding speeds. The results indicated that the tribological performance of these materials in vacuum depends on both compositions and test conditions. At low sliding speed, a very low friction and wear coefficients were obtained while at higher speed, severe wear occurred. In particular, CF filled composites showed excessive wear that led to the ignition after opening the vacuum chamber. Experimental results are discussed by analyzing the transfer film and wear debris.


2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Vineet Tirth

AA2218–Al2O3(TiO2) composites are synthesized by stirring 2, 5, and 7 wt % of 1:2 mixture of Al2O3:TiO2 powders in molten AA2218 alloy. T61 heat-treated composites characterized for microstructure and hardness. Dry sliding wear tests conducted on pin-on-disk setup at available loads 4.91–13.24 N, sliding speed of 1.26 m/s up to sliding distance of 3770 m. Stir cast AA2218 alloy (unreinforced, 0 wt % composite) wears quickly by adhesion, following Archard's law. Aged alloy exhibits lesser wear rate than unaged (solutionized). Mathematical relationship between wear rate and load proposed for solutionized and peak aged alloy. Volume loss in wear increases linearly with sliding distance but drops with the increase in particle wt % at a given load, attributed to the increase in hardness due to matrix reinforcement. Minimum wear rate is recorded in 5 wt % composite due to increased particles retention, lesser porosity, and uniform particle distribution. In composites, wear phenomenon is complex, combination of adhesive and abrasive wear which includes the effect of shear rate, due to sliding action in composite, and abrasive effect (three body wear) of particles. General mathematical relationship for wear rate of T61 aged composite as a function of particle wt % load is suggested. Fe content on worn surface increases with the increase in particle content and counterface temperature increases with the increase in load. Coefficient of friction decreases with particle addition but increases in 7 wt % composite due to change in microstructure.


2014 ◽  
Vol 10 (2) ◽  
pp. 276-287
Author(s):  
Rajesh Siriyala ◽  
A. Gopala Krishna ◽  
P. Rama Murthy Raju ◽  
M. Duraiselvam

Purpose – Since, wear is the one of the most commonly encountered industrial problems leading to frequent replacement of components there is a need to develop metal matrix composites (MMCs) for achieving better wear properties. The purpose of this paper is to fabricate aluminum MMCs to improve the dry sliding wear characteristics. An effective multi-response optimization approach called the principal component analysis (PCA) was used to identify the sets of optimal parameters in dry sliding wear process. Design/methodology/approach – The present work investigates the dry sliding wear behavior of graphite reinforced aluminum composites produced by the molten metal mixing method by means of a pin-on-disc type wear set up. Dry sliding wear tests were carried on graphite reinforced MMCs and its matrix alloy sliding against a steel counter face. Different contact stress, reinforcement percentage, sliding distance and sliding velocity were selected as the control variables and the response selected was wear volume loss (WVL) and coefficient of friction (COF) to evaluate the dry sliding performance. An L25 orthogonal array was employed for the experimental design. Optimization of dry sliding performance of the graphite reinforced MMCs was performed using PCA. Findings – Based on the PCA, the optimum level parameters for overall principal component (PC) of WVL and COF have been identified. Moreover, analysis of variance was performed to know the impact of individual factors on overall PC of WVL and COF. The results indicated that the reinforcement percentage was found to be most effective factor among the other control parameters on dry sliding wear followed by sliding distance, sliding velocity and contact stress. Finally the wear surface morphology of the composites has been investigated using scanning electron microscopy. Practical implications – Various manufacturing techniques are available for processing of MMCs. Each technique has its own advantages and disadvantages. In particular, some techniques are significantly expensive compared to others. Generally the manufacturer prefers the low cost technique. Therefore stir casting technique which was used in this paper for manufacturing of Aluminum MMCs is the best alternative for processing of MMCs in the present commercial sectors. Since the most important criteria of a dry sliding wear behavior is to provide lower WVL and COF, this study has intended to prove the application of PCA technique for solving multi objective optimization problem in wear applications like piston rings, piston rods, cylinder heads and brake rotors, etc. Originality/value – Application of multi-response optimization technique for evaluation of tribological characteristics for Aluminum MMCs made up of graphite particulates is a first-of-its-kind approach in literature. Hence PCA method can be successfully used for multi-response optimization of dry sliding wear process.


2017 ◽  
Vol 139 (4) ◽  
Author(s):  
N. Radhika ◽  
R. Raghu

LM13/AlN (10 wt. %) metal matrix composites (MMC) and unreinforced aluminum alloy were produced under stir casting route. Microstructural characteristics were examined on the developed composite using optical microscope. The hardness and tensile test were carried out on both unreinforced aluminum alloy and composite using Vickers hardness tester and universal testing machine (UTM), respectively. Dry sliding wear behavior of the composite and unreinforced aluminum alloy was evaluated using pin-on-disk tribometer based on the design of experiments approach. Experimental parameters such as applied load (10, 20, and 30 N), velocity (1, 2, and 3 m/s), and sliding distance (500, 1000, and 1500 m) were varied for three levels. Signal-to-noise (S/N) ratio analysis, analysis of variance, and regression analysis were also performed. The characterization results showed that reinforcement particles were uniformly distributed in the composite. The hardness and tensile test revealed greater improvement of property in composite compared to that of unreinforced alloy. Wear plot showed that wear was increased with increase in load and decreased with increase in velocity and sliding distance. S/N ratio analysis and analysis of variance (ANOVA) indicated that load has greater significance over the wear rate followed by velocity and sliding distance. Regression analysis revealed greater adequacy with the constructed model in predicting the wear behavior of composite and unreinforced aluminum alloy. Scanning electron microscopy (SEM) analysis is evident that the transition of wear from mild to severe occurred on increase of the load in the composite.


2009 ◽  
Vol 423 ◽  
pp. 125-130 ◽  
Author(s):  
Alvaro Mestra ◽  
Gemma Fargas ◽  
Marc Anglada ◽  
Antonio Mateo

Duplex stainless steels contain similar amounts of austenite  and ferrite α. This two-phase microstructure leads to an excellent combination of mechanical properties and corrosion resistance. However, there are few works dealing with the wear behaviour of these steels. This paper aims to determine the sliding wear mechanisms of a duplex stainless steel type 2205. In order to do it, three different sliding velocities (0.2, 0.7 and 1.2 m/s) and six sliding distances (500, 1000, 2000, 3000, 4000 and 5000 m) were selected. The results show that wear rate depends on both sliding velocity and sliding distance. The wear mechanisms detected were plowing, microcracking and microcutting (typical mechanisms of fatigue wear). These mechanisms evolve according to sliding velocity and sliding distance, highlighting a transition zone in which wear rate is reduced.


2007 ◽  
Vol 280-283 ◽  
pp. 1327-1330
Author(s):  
Chien Cheng Liu ◽  
Jow Lay Huang

The effects of TiN addition to Si3N4 on its mechanical and wear properties were investigated. The size and content of TiN particles were found having effects on the strength and toughness of Si3N4-based composites. The friction and wear behavior of Si3N4 based composites against AISI-52100 steel were investigated in the ball -on- disc mode in a non-lubrication reciprocation motion. It has been found that under the conditions used all the ceramic components exhibited rather low friction and wear coefficients. For monolithic silicon nitride materials, high friction coefficients between 0.6 and 0.7 and wear coefficients between 1.63 × 10-8 and 1.389 × 10-6 mm3/N.m were measured. The contact load was varied from 100 to 300 N. By adding titanium nitride, the friction coefficients was reduced to a value between 0.4 and 0.5 and wear coefficients between 1.09×10-8 and 0.32×10-6 mm3/N.m at room temperature.


2009 ◽  
Vol 79-82 ◽  
pp. 2199-2202 ◽  
Author(s):  
Joon Ho Seo ◽  
Jin Yong Kim ◽  
Seung Uk Park ◽  
Hyun Chul Kim ◽  
Byung Chul Na ◽  
...  

The piston pin contact in a typical automotive engine is an example of a highly loaded. Therefore, for piston pin design several aspects are important. Among them are function, cost, NVH, fuel economy, durability, and impact on other design aspects of the engine. Continuously contacting with piston pin, the face of connecting rod, brings about abnormal wear such as unfairwear or earlywear. because the engine get more powered and one requirement for a good fuel economy is to achieve a low level of mechanical friction. In this study, modern low friction coatings and treatment at the piston pin interface aimed to investigate the potential. The profile of coated specimens were observed by non-contact type optical surface measuring system and the friction-wear behaviors of coated specimens were investigated by using piston pin wear tester. Piston pin wear test was performed to analyze the friction and wear behavior. The results showed that the application of low friction coatings and treatment effectively improved tribological performance of the piston pin


2021 ◽  
Vol 49 (2) ◽  
pp. 414-421
Author(s):  
Manjunath Naik ◽  
L.H. Manjunath ◽  
Vishwanath Koti ◽  
Avinash Lakshmikanthan ◽  
Praveennath Koppad ◽  
...  

Graphene and carbon nanotubes are two carbon based materials known for their unique wear and friction properties. It would be quite interesting to understand the wear behavior of aluminium hybrid composites when these two nanosize reinforcements are incorporated into it. The hybrid composites with varying weight fractions of graphene (1, 2, 3 and 5 wt.%) and fixed CNT content of 2 wt.% were produced using powder metallurgy technique. The effect of varying graphene content on hardness and sliding wear of hybrid composites was studied. The wear tests were done as per ASTM G-99 standard with fixed sliding velocity (2 m/s) and sliding distance (1200 m) but varying applied load (10 - 30 N). Worn surface analysis was conducted using scanning electron microscope to arrive at wear mechanisms responsible for wear of aluminium and its hybrid composites. Increase in graphene content led to increase in bulk hardness with highest value of 61 RHN for hybrid composite with 3 wt.% graphene content. The wear rate of hybrid composites was found to be decreasing with enhancement in graphene content. Lower wear rate in hybrid composites was due to the formation of lubricating layer on the worn surface.


2013 ◽  
Vol 747-748 ◽  
pp. 152-157 ◽  
Author(s):  
Shu Fa Chen ◽  
Cheng Long Feng ◽  
Jin Yang ◽  
Jin Song Chen

In this study, the dry sliding wear behavior of Ni-based self-lubricating wear-resistant coating was characterized under various loads at 300 . Morphologies and compositions of the worn surface were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results showed that with the increase of load, both the frictional coefficient and wear rate decreased firstly, then slightly increased. A small amount of debris dispersed on the worn surface of the coating under low load (2 N). Since the effects of oxide layer and lubricant particles spreading onto the worn surface, the coating exhibited superior friction, and improved the wear properties under moderate load (5 N). As the load further increased, till up to 10N, the worn surface started to appear some shallow grooves and craters. This was contributed to the dispersion of carbides and lubricant particles.


2021 ◽  
Vol 13 (4) ◽  
pp. 139-150
Author(s):  
P. MUTHU

Dry sliding wear plays an important role in selecting material for automotive and aerospace applications. Researchers have been exploring novel aluminum matrix composites (AMC), which offer minimum wear rate for various tribological applications. The present work involves multi-objective optimization for dry sliding wear behavior of Al6061 reinforced with 6 % of Titanium carbide and 4% of basalt hybrid metal matrix composites using principal component analysis (PCA)-based grey relational analysis (GRA). In this article, the effects of input variables of wear parameters such as applied load, sliding speed and sliding distance were investigated on different output responses, namely the wear rate, friction force and specific wear rate. Taguchi’s L9 orthogonal array with three-level settings was chosen for conducting experiments. Three output responses in each experiment were normalized into a weighted grey relational grade using grey relational analysis coupled with the principal component analysis. The analysis of variance indicated that sliding distance is the most influential parameter followed by load and sliding velocity that contributes to the quality characteristics. Optimal results have been verified through additional experiments.


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