The influence of alumina on mechanical and tribological characteristics of graphite particle reinforced hybrid Al-MMC

2014 ◽  
Vol 28 (11) ◽  
pp. 4737-4744 ◽  
Author(s):  
A. Arun Premnath ◽  
T. Alwarsamy ◽  
T. Rajmohan ◽  
R. Prabhu
Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 857
Author(s):  
Ahmed Fouly ◽  
Ahmed Mohamed Mahmoud Ibrahim ◽  
El-Sayed M. Sherif ◽  
Ahmed M.R. FathEl-Bab ◽  
A.H. Badran

Denture base materials need appropriate mechanical and tribological characteristics to endure different stresses inside the mouth. This study investigates the properties of poly(methyl methacrylate) (PMMA) reinforced with different low loading fractions (0, 0.2, 0.4, 0.6, and 0.8 wt.%) of hydroxyapatite (HA) nanoparticles. HA nanoparticles with different loading fractions are homogenously dispersed in the PMMA matrix through mechanical mixing. The resulting density, Compressive Young’s modulus, compressive yield strength, ductility, fracture toughness, and hardness were evaluated experimentally; the friction coefficient and wear were estimated by rubbing the PMMA/HA nanocomposites against stainless steel and PMMA counterparts. A finite element model was built to determine the wear layer thickness and the stress distribution along the nanocomposite surfaces during the friction process. In addition, the wear mechanisms were elucidated via scanning electron microscopy. The results indicate that increasing the concentration of HA nanoparticles increases the stiffness, compressive yield strength, toughness, ductility, and hardness of the PMMA nanocomposite. Moreover, tribological tests show that increasing the nanoparticle weight fraction considerably decreases the friction coefficient and wear loss.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Arun M. ◽  
Muthukumaran M. ◽  
Balasubramanian S.

Purpose Dissimilar materials found applications in the structural fields to withstand the different types of loads and provide multi-facet properties to the final structure. Aluminum alloy materials are mostly used in aerospace and marine industries to provide better strength and safeguard the material from severe environmental conditions. The purpose of this study is to develop new material with superior strength to challenge the severe environmental conditions. Design/methodology/approach In the present investigation, friction stir welding (FSW) dissimilar joints were prepared from AA6061 and AA5083 aluminum alloys, and the weld nugget (WN) was reinforced with hard reinforcement particles such as La2O3 and CeO2. The tribological and mechanical properties of the prepared materials were tested to analyze the suitability of material in the aerospace and marine environmental conditions. Findings The results showed that the AA6061–AA5083/La2O3 material exhibited better mechanical and tribological characteristics. The FSW dissimilar AA6061–AA5083/La2O3 material exhibited lower wear rate of 7.37 × 10−3 mm3/m and minimum friction coefficient of 0.31 compared to all other materials owing to the reinforcing effect of La2O3 particles and the fine grains formed by FSW process at WN region. Further, FSW dissimilar AA6061–AA5083/La2O3 material displayed a maximum tensile strength and hardness of 378 MPa and 118 HV, respectively, among all the other materials tested. Originality/value This work is original and novel in the field of materials science engineering focusing on tribological characteristics of friction stir welded dissimilar aluminum alloys by the reinforcing effect of hard particles such as La2O3 and CeO2.


2019 ◽  
Vol 1355 ◽  
pp. 012032
Author(s):  
Abhishek Arora ◽  
K Uday Venkat Kiran ◽  
Bijoy Ramakrishnan ◽  
B. Ratna Sunil ◽  
Ravikumar Dumpala

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 859
Author(s):  
Ruslan Karimbaev ◽  
Seimi Choi ◽  
Young-Sik Pyun ◽  
Auezhan Amanov

This study introduces a newly developed cladding device, through printing AISI 1045 carbon steel as single and double layers onto American Society for Testing and Materials (ASTM) H13 tool steel plate. In this study, the mechanical and tribological characteristics of single and double layers were experimentally investigated. Both layers were polished first and then subjected to ultrasonic nanocrystal surface modification (UNSM) treatment to improve the mechanical and tribological characteristics. Surface roughness, surface hardness and depth profile measurements, and X-ray diffraction (XRD) analysis of the polished and UNSM-treated layers were carried out. After tribological tests, the wear tracks of both layers were characterized by scanning electron microscopy (SEM) along with energy-dispersive X-ray spectroscopy (EDX). The surface roughness (Ra and Rz) of the single and double UNSM-treated layers was reduced 74.6% and 85.9% compared to those of both the as-received layers, respectively. In addition, the surface hardness of the single and double layers was dramatically increased, by approximately 23.6% and 23.4% after UNSM treatment, respectively. There was no significant reduction in friction coefficient of both the UNSM-treated layers, but the wear resistance of the single and double UNSM-treated layers was enhanced by approximately 9.4% and 19.3% compared to the single and double polished layers, respectively. It can be concluded that UNSM treatment was capable of improving the mechanical and tribological characteristics of both layers. The newly developed cladding device can be used as an alternative additive manufacturing (AM) method, but efforts and upgrades need to progress in order to increase the productivity of the device and also improve the quality of the layers.


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