Dry Sliding Wear Behavior of EB Surface-Alloyed and Dispersed AZ91 Magnesium Alloy under Mild Wear Conditions

2015 ◽  
Vol 828-829 ◽  
pp. 272-278
Author(s):  
Katja Fritzsch ◽  
Anja Buchwalder ◽  
Rolf Zenker

This paper reports on investigations of the beneficial effects of electron beam alloying (EBA) and electron beam dispersion alloying (EBDA) on the wear behavior of AZ91D Mg alloy under mild wear conditions with applied normal loads of 1…10 N. The layers generated had a thickness of 1.5 mm with Al contents of 30 wt.%. For dispersion alloyed layers, TiC was added with particle sizes of 20…100 µm. At a sliding distance of 20 m, the wear rates of alloyed layers (150 HB) and dispersion alloyed layers (180 HB) were almost the same and could be reduced by half compared to the untreated AZ91D (60 HB). Due to their large size and the large spaces between them, TiC particles were pressed into the layer matrix, or were torn out and acted as additional abrasives. Therefore, at a sliding distance of 50 m, the wear rate of dispersion alloyed layers increased to the level of the base material.

Wear ◽  
2017 ◽  
Vol 390-391 ◽  
pp. 1-10 ◽  
Author(s):  
S. García-Rodríguez ◽  
B. Torres ◽  
A. Maroto ◽  
A.J. López ◽  
E. Otero ◽  
...  

2010 ◽  
Vol 105-106 ◽  
pp. 130-132
Author(s):  
Jun Ping Yao ◽  
Sun Zhong ◽  
Lei Zhang ◽  
Huo Ping Zhao

TiC reinforced AZ91 magnesium matrix composites have been fabricated by a melt in-situ reaction spray deposition. The microstructures of spray-deposited alloys were studied by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The dry sliding wear behavior of the alloys was investigated by using a pin-on-disc machine under five loads, namely 10, 20, 30, 40 and 50 N. It has been found that the wear behavior of the alloys was dependent on the TiC content in the microstructure and the applied load. At a lower load (10 N), with increasing TiC content, the wear rate of the alloy was decreased, and the dominant wear mechanism was an oxidative mechanism. At a higher load (50 N), a spray- deposited AZ91/TiC composites exhibited superior wear resistance to the AZ91 magnesium alloy, the dominant wear mechanism was delamination.


2015 ◽  
Vol 830-831 ◽  
pp. 333-336 ◽  
Author(s):  
M. Ananda Jothi ◽  
S. Ramanathan

Titanium and its alloys exhibit a unique combination of physical and corrosion resistance properties which make them ideal materials for space flight engine component such as disks and blades of compressor, marine applications, chemical industries and many bio medical applications. However the use of these materials is limited due to its poor tribological properties. Dry sliding wear tests were performed on Ti-6Al-4V using a pin-on-disc (EN31 steel) configuration. Wear rates were measured with different load and sliding velocity at a constant sliding distance. Microstructures of worn surfaces were characterized by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).


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.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 296 ◽  
Author(s):  
Chao Sun ◽  
Nannan Lu ◽  
Huan Liu ◽  
Xiaojun Wang ◽  
Xiaoshi Hu ◽  
...  

In this study, the dry sliding wear behaviors of SiC particle reinforced AZ91D matrix composites fabricated by stirring casting method were systematically investigated. The SiC particles in as-cast composites exhibited typical necklace-type distribution, which caused the weak interface bonding between SiC particles and matrix in particle-segregated zones. During dry sliding at higher applied loads, SiC particles were easy to debond from the matrix, which accelerated the wear rates of the composites. While at the lower load of 10 N, the presence of SiC particles improved the wear resistance. Moreover, the necklace-type distribution became more evident with the decrease of particle sizes and the increase of SiC volume fractions. Larger particles had better interface bonding with the matrix, which could delay the transition of wear mechanism from oxidation to delamination. Therefore, composites reinforced by larger SiC particles exhibited higher wear resistance. Similarly, owing to more weak interfaces in the composites with high content of SiC particles, more severe delamination occurred and the wear resistance of the composites was impaired.


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.


2012 ◽  
Vol 562-564 ◽  
pp. 318-321 ◽  
Author(s):  
Xiao Peng Huang ◽  
Jing Feng Wu ◽  
Fang Xin Wan ◽  
Ke Ping Zhang

In this study, the wear behavior of 9SiCr steel under different treatment with plant abrasive was evaluated by using an abrasive rubber wheel tester. The samples’ microstructures were analyzed by a metallurgical microscope, the samples’ worn surface morphology was observed by using SEM.The results show that: With the increasing of hardness of sample, Its wear resistance is greatly improved. Hardness of laser quenching sample is the highest, wear resistance of it is the best, the second is sub temperature sample. The wear rates and the wear coefficients are proportional to the sliding distance. The Laser quenching samplel display a consistent behaviour with a very low wear rate and a small increase of the wear damage is observed during the abrasive wear tests. The worn surfaces of the three kind samples are characterized by the micro-cutting wear, and no treatment sample is accompanied by fatigue wear mechanism.


2011 ◽  
Vol 465 ◽  
pp. 495-498 ◽  
Author(s):  
Pavol Hvizdoš ◽  
Annamária Duszová ◽  
Viktor Puchý ◽  
Orsolya Tapasztó ◽  
Peter Kun ◽  
...  

Tribological behavior of ZrO2 and Si3N4 based nanocomposites with addition of carbon nanofibres and nanotubes has been studied by the pin-on-disc technique. Friction coefficients were measured and recorded, wear rates were calculated in terms of material volume loss per load and sliding distance. The wear damage was studied using optical and electron microscopy and its mechanisms were identified. In monolithic materials the dominant wear mechanism was abrasion, in composites with CNF and with higher volume fraction of CNTs (5 and 10%) fiber pull-out and lubricating by the carbon phases occurred.


2014 ◽  
Vol 33 (1) ◽  
pp. 41-48 ◽  
Author(s):  
F. Yıldız

AbstractIn this study, conventional WC-12Co cermet coatings were deposited on AZ91 magnesium alloy using High Velocity Oxy-Fuel spray method. The effects of different coating thicknesses (60 and 120 µm) and wear loads (20 and 30 N) on tribological properties of AZ91 magnesium alloy coated with WC-12Co were investigated. Structural, mechanical and tribological properties of WC-12Co coatings were analyzed by means of X-ray diffractometer, scanning electron microscope, micro-hardness tester and pin-on-disc tribotester. It was observed that WC-12Co coating is an effective method for improving the wear behavior of AZ91 magnesium alloy.


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