scholarly journals The Hardness Of Ion Implanted Ceramics

1985 ◽  
Vol 60 ◽  
Author(s):  
W. C. Oliver ◽  
C. J. McHargue ◽  
G. C. Farlow ◽  
C. W. White

AbstractIt has been established that the wear behavior of ceramic materials can be modified through ion implantation. Studies have been done to characterize the effect of implantation on the structure and composition of ceramic surfaces. To understand how these changes affect the wear properties of the ceramic, other mechanical properties must be measured. To accomplish this, a commercially available ultra low load hardness tester has been used to characterize Al 2O3 with different implanted species and doses. The hardness of the base material is compared with the highly damaged crystalline state as well as the amorphous material.

Author(s):  
Amit Aherwar ◽  
Amit Singh ◽  
Amar Patnaik ◽  
Deepak Unune

In this study, a series of implant material containing molybdenum of different weight percentages were fabricated via high temperature vertical vacuum casting induction furnace and examined their physical, mechanical and wear properties. The mechanical properties were tested by the micro-hardness tester and the compression testing machine, while the wear performance was analyzed through a pin-on-disc tribometer under different operating conditions at room temperature. Density, hardness, compressive strength and sliding wear were considered as criterions for this study. The proportions of alternatives consist of Co-30Cr as a base material and molybdenum as an alloying element which was varied from 0 to 4wt.%. Due to the conflict between the properties obtained, the Grey relational analysis method (GRA) was applied to choose the best material among the set of alternatives. From the results obtained, it was found that Co-30Cr implant material containing 4wt.%molybdenum provides the best combination of the properties for a given application (i.e. hip femoral head).


2017 ◽  
Vol 7 (1.1) ◽  
pp. 193
Author(s):  
M.H. Faisal ◽  
S. Prabagaran ◽  
T.S. Vishnu

Aluminium/graphite composites are the need of modern times for addressing the fuel saving issues. The graphite in such composites act as solid lubricant and it reduce external fuel requirements. But such composites are having degraded mechanical properties due to the graphite content in composite. In order to solve the negative effect of graphite on mechanical properties of LM13/Gr self-lubricating composite this study was conducted to find out the mechanical properties of LM13/B4C/Gr Metal Matrix Composites. Boron carbide was selected as reinforcement because of its better reinforcement properties compared to alumina and silicon carbide. The properties of the hybrid composites were compared with the LM13/Gr self-lubricating composite to study the enhancement in mechanical properties that has been caused by the boron carbide particles. Using computerized universal testing machine and rock-well hardness tester mechanical properties such as hardness and tensile strength were tested. Pin on disk testing machine was used to analyse the wear behavior. The test results indicates that by raising weight % of boron carbide particles in the LM13, tensile strength and hardness of the hybrid composites was increased compared to self-lubricating composite accompanied by better tribological properties.


2013 ◽  
Vol 6 (2) ◽  
pp. 139-153
Author(s):  
Israa .A.K

This research is devoted to study the effect of addition of different weight percent from SiCp ( 2, 4, 6, 8 ) to Al– 4 Cu alloy which have been fabricated by liquid metallurgy method on the dry sliding wear behavior and mechanical properties. Wear characteristics of Al–SiC composites have been investigated under dry sliding conditions and compared with base alloy. Dry sliding wear tests have been carried out using pin-on-disk wear test under normal applied loads 5, 10, 15 and 20 N and at different sliding velocity of (2.7, 3.7, 4.7) m/sec. It was also observed that the wear rate varies linearly with increases normal applied load but lower in composites as compared to the base material. The wear mechanism appears to be oxidative for both Al – Cu alloy and composites under the given conditions of load and sliding velocity as indicated by optical microscopic of the worn surfaces. Further, it was found from the experimentation that the wear rate decreases linearly with increasing weight percent of silicon carbide. The best results have been obtained at 8 % wt SiC . We also observed that the yield strength, tensile strength increases with increasing wt% of SiC , but the ductility decreases.


Friction ◽  
2020 ◽  
Author(s):  
Jinjuan Cheng ◽  
Mincong Mao ◽  
Xueping Gan ◽  
Qian Lei ◽  
Zhou Li ◽  
...  

Abstract Alloys used as bearings in aircraft landing gear are required to reduce friction and wear as well as improve the load-carrying capability due to the increased aircraft weights. Cu-15Ni-8Sn-0.8Nb alloy is well known for possessing good mechanical and wear properties that satisfy such requirements. In this study, the microstructure, mechanical properties, and grease-lubricated sliding wear behavior of Cu-15Ni-8Sn-0.8Nb alloy with 0.8 wt% Nb are investigated. The nanoscale NbNi3 and NbNi2Sn compounds can strengthen the alloy through the Orowan strengthening mechanism. A Stribeck-like curve is plotted to illustrate the relationship among friction coefficient, normal load, and sliding velocity and to analyze the grease-lubricated mechanism. The wear rate increases with normal load and decreases with sliding velocity, except at 2.58 m/s. A wear mechanism map has been developed to exhibit the dominant wear mechanisms under various friction conditions. When the normal load is 700 N and the sliding velocity is 2.58 m/s, a chemical reaction between the lubricating grease and friction pairs occurs, resulting in the failure of lubricating grease and an increase in wear.


2021 ◽  
pp. 1-24
Author(s):  
Aluru Praveen Sekhar ◽  
Debdulal Das

Abstract This study aims to correlate the abrasive wear performance with mechanical properties, considering AA6063 Al-Mg-Si alloy as the model material. The selected alloy specimens are subjected to artificial ageing at 150 °C for an ageing duration ranging from 1 to 672 h, covering severely under-aged (SUA) to peak-aged (PA) to severely over-aged (SOA) states. Apart from the hardness and tensile properties, two-body abrasive wear properties are also evaluated for differently aged alloys in terms of wear rate, coefficient of friction, and roughness of the abraded surfaces. Furthermore, the generated wear debris, surface, and sub-surface of the abraded specimens are critically examined to reveal the micro-mechanisms of abrasion. The lowest amount of wear rate is observed for a PA alloy with maximum hardness, while the OA alloy exhibits a slightly lower wear rate than the UA alloy at a similar level of hardness. Statistical analyses of wear rate and various mechanical properties of all heat-treated alloys establish a strong negative linear correlation between the wear rate and hardness, yield strength, tensile strength, and strength coefficient; whereas, a positive linear correlation with the strain hardening exponent. Relationships between wear rate and different roughness parameters are also discussed. Under the investigated wear condition, the aged alloys endure significant plastic deformation; micro-plowing, micro-cutting, and delamination are found to be the predominant mechanisms during abrasion.


2011 ◽  
Vol 299-300 ◽  
pp. 798-801 ◽  
Author(s):  
Yan Hui Liu ◽  
Jing Long Gao

Polypropylene(PP)/carbon nanotube(CNTs) nanocomposites with different CNTs fraction were prepared by the melting blend method. The effects of CNTs content on the wear properties and mechanical properties were mainly investigated. The results show that the friction coefficient of the nanocomposites decreased as the concentration of CNTs is increased. With increasing CNTs content, tensile strength, ultimate strain, compact strength and Young’s modules increase firstly and then decrease. For the composite with an effective CNTs content of 3 wt, its tensile strength, ultimate strain, compact strength and Young's modules were improved by 72, 44.4,88 and 37 %, respectively, as compared to PP.


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.


2019 ◽  
Vol 8 (2) ◽  
pp. 6062-6066

In this study, the effect of tool pin geometry on the microstructure and mechanical properties friction stir processed (FSP) specimens of ZE41 magnesium alloy were investigated. The four different tool pin profiles such as triangular, square, taper cylindrical and threaded taper cylindrical with process parameters of 1120 RPM, 25mm/min and tool tilt angle 10 were considered. Microstructures of the processed specimens are examined using scanning electron microscope (SEM) and the wear behavior was observed using pin on disk tribometer. The consequences show that the triangular tool pin produced defect free joints, finest microstructure, higher mechanical and wear properties.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
B. R. Senthil Kumar ◽  
M. Thiagarajan ◽  
K. Chandrasekaran

This work has investigated to find the influence of silicate on the wear behavior of LM 24/4 wt.% fly ash hybrid composite. The investigation reveals the effectiveness of incorporation of silicate in the composite for gaining wear reduction. Silicate particles with fly ash materials were incorporated into aluminum alloy matrix to accomplish reduction in wear resistance and improve the mechanical properties. The LM24/silicate/fly ash hybrid composite was prepared with 4 wt.% fly ash particles with 4, 8, 12, 16, 20, and 24 wt.% of silicate using vortex technique. Tribological properties were evaluated under different load (15, 30, 45, 60, and 75 N); sliding velocity (0.75, 1.5, 2.25, and 3 m/sec) condition using pin on disc apparatus and mechanical properties like density, hardness, impact strength, and tensile strength of composites were investigated. In addition, the machining of the aluminum hybrid composite was studied using Taguchi L9orthogonal array with analysis of variance. The properties of the hybrid composites containing 24 wt.% silicates exhibit the superior wear resistance and mechanical properties.


2011 ◽  
Vol 304 ◽  
pp. 6-11 ◽  
Author(s):  
Xiao Qian Qi ◽  
Xu Ping Zhang

Al-matrix self-lubricating which added MoS2 as solid lubricant was prepared by casting under variation in content of Si、Fe、Mn、MoS2、Cr3C2. Friction and wear behavior were investigated on MPX-2000 friction and abrasion machine. The microscopic structure and phases were analyzed by metallographic microscopic and XRD. The results show that the main factor influencing friction coefficient is Si, it can reduce the wear rate. Addition of MoS2 can reduce friction coefficient, Fe is used to improve the mechanical properties. Cr3C2 enhances the wear resistance.


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