Novel investigation on tribological behavior of microwave synthesized functionally graded claddings

Author(s):  
Sarbjeet Kaushal ◽  
Dheeraj Gupta ◽  
Hiralal Bhowmick

In this study, functional performance of Ni/Cr3C2 functionally graded claddings (FGCs) was investigated under dry sliding wear environment. The Ni/Cr3C2-based FGCs were produced by varying Cr3C2 fraction (Ni-XCr3C2) (X=10%–30% by weight) using microwave irradiation. The FGC layers were composed of cellular-structure with reinforced particles dispersed randomly inside Ni-based matrix. Variation of Cr3C2 particles inside Ni matrix exhibited significant impact on micro-structural and mechanical properties. The microhardness profile of the FGC layers showed an increase in hardness value with an increase in the amount of reinforced Cr3C2 particles. FGC top layers showed the maximum value of micro-hardness of 555 ± 34 HV. Functional performance of microwave processed FGCs was studied through the pin-on-disk tribometer under varying sliding velocity and sliding distances. For comprehension study, wear study was also carried out on microwave processed single layer clads with compositions corresponding to FGC layers. The FGC sample showed better wear resistance than all single clad layers and substrate material. The FGC sample exhibited 1.6 times less wear rate than the Ni-based + 30% Cr3C2 single layer clad. The worn-out surfaces of FGC and single-layer-clads showed presence of multiples cracks and grooves, which resulted in their weight loss during dry sliding contact. Material debonding and the formation of craters and cracks are the main phenomena responsible for the wear loss in the FGC surface.

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1749 ◽  
Author(s):  
Qing Zhang ◽  
Jie Gu ◽  
Shuo Wei ◽  
Ming Qi

The dry sliding wear behavior of the Al-12Si-CuNiMg matrix alloy and its composite reinforced with Al2O3 fibers was investigated using a pin-on-disk wear-testing machine. The volume fraction of Al2O3 fibers in the composite was 17 vol.%. Wear tests are conducted under normal loads of 2.5, 5.0, and 7.5 N, and sliding velocities of 0.25, 0.50, and 1.0 m/s. Furthermore, the worn surfaces of the matrix alloy and the composite were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results showed that the wear resistance of the composite was inferior to that of the matrix alloy, which could be attributed to the high content of reinforcement and casting porosities in the composite. Worn-surface analysis indicates that the dominant wear mechanisms of both materials were abrasive wear and adhesive wear under the present testing conditions.


2011 ◽  
Vol 314-316 ◽  
pp. 137-142
Author(s):  
Bin Cai ◽  
Ye Fa Tan ◽  
Hui Yong Ji ◽  
Xiao Long Wang ◽  
Long He ◽  
...  

In order to reduce friction coefficient of the Ni-base alloy coating and further improve its wear resistance, the graphite/TiC/Ni-base alloy composite coating was prepared on the surface of 45 carbon steel by plasma spray. Effects of loads, friction counterparts and lubricants on tribological properties of the coating were investigated. The results show that friction coefficient of the composite coating is reduced by 33% than that of the Ni-base alloy coating when worn against GCr15. Wear losses of the composite coating are less than those of the Ni-base alloy coating at all loads of 6N, 8N, 10N and 12N. Worn against Si3N4, friction coefficient of the composite coating is 13% less than that worn against GCr15, but its wear loss is 2.9 times of that worn against GCr15. Wear mechanism of the composite coating is micro cutting and brittle fraction when worn against Si3N4. Under lubrication of NaCl solution, friction coefficient of the composite coating is almost the same as that under dry sliding, wear loss is increased by 1.6 times. Stress corrosion and wedging effects of the NaCl solution are main wear mechanisms of the composite coating.


Author(s):  
Ajith Kurian Baby ◽  
M Priyaranjan ◽  
K Deepak Lawrence ◽  
PK Rajendrakumar

Hypereutectic Al-Si alloys are used as material for the engine block and cylinder liners in automobiles. Wear behaviour of hypereutectic Al-Si alloy system changes significantly with applied normal load in both mild wear and severe wear regime. Significant improvement in wear resistance can be obtained by exposing silicon particles through the chemical etching process. For Al-25% Si alloys, most studies are reported in mild and ultra-mild wear regime. In the present work, the wear of exposed silicon particles with varying load and speed in severe wear regime was investigated under the unidirectional sliding condition and bi-directional sliding condition using a pin-on-disk tribometer (POD) and a linear reciprocating tribometer (LRT), respectively. Rapidly solidified and T6 heat-treated Al-25Si alloy was polished and etched using 5% NaOH solution to expose the silicon particles. Experiments were carried out with normal loads varying from 40 N to 120 N in dry sliding conditions. Sliding speeds of 0.8 m/s and 1.5 m/s were applied for each load in case of a pin on disk tribometer whereas, in an LRT, the sliding velocities were 0.2 m/s and 0.45 m/s respectively for each set of the load. The surface topography was measured by means of a 3-D optical profilometer, and surface morphology was analyzed using SEM images. It was observed that at higher loads, larger Si particles were fractured and pushed into the matrix. Fractured silicon particles, along with smaller particles, were embedded into the matrix, thereby increasing the silicon concentration in the wear region. The comparison of the experimental results of unidirectional and bi-directional sliding that reveal the change in surface morphology of silicon particles, the friction characteristics at the interface, variation of surface 3-D roughness parameters, the wear rate and wear mechanisms of Al-25% Si alloys are analyzed and reported in the study.


2015 ◽  
Vol 813-814 ◽  
pp. 218-225 ◽  
Author(s):  
T. Rajmohan ◽  
D. Kumar ◽  
S. Manimaran

Poly-ether-ether-ketone (PEEK) becomes one of the most promising polymer material for the tribological applications because of its outstanding performance such as high mechanical properties, high chemical resistance, and high wear resistance. The present work is focused on optimization of dry sliding wear parameters of MWCNT reinforced PEEK matrix composites using RSM based desirability approach. The materials used for the present investigation are unreinforced PEEK and reinforced with 0.5% and 1% MWCNT. Wear parameters such as load, sliding speed and % of MWCNT are chosen as control factors to optimize the wear loss and coefficient of friction. An experimental plan of a L9 based on Taguchi design is employed to carry out the experimental study. After conducting experiment, mathematical models have been developed to fit the output responses using Response surface methodology and drilling parameters have been optimized using Desirability based approach. This methodology deals with the development of modelling equations for each response. The relative significance of the various parameters has been found using ANOVA.


2007 ◽  
Vol 534-536 ◽  
pp. 629-632
Author(s):  
Süleyman Tekeli ◽  
Ahmet Güral ◽  
Metin Gürü

The effect of tempering temperature and microstructure on dry sliding wear behavior of quenched and tempered PM steels was investigated. For this purpose, atomized iron powder was mixed with 0.3 % graphite and 1-2 % Ni powders. The mixed powders were cold pressed and sintered at 1200°C. The sintered specimens were quenched from 890°C and then tempered at 200°C and 600°C for 1 hr. Wear tests were carried out on the quenched+tempered specimens under dry sliding wear conditions using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively increased with increasing tempering temperature. With increasing Ni content, the wear coefficient slightly decreased at all tempering temperatures due to the high amount of Ni-rich austenitic areas.


2007 ◽  
Vol 534-536 ◽  
pp. 673-676 ◽  
Author(s):  
Ahmet Güral ◽  
Süleyman Tekeli ◽  
Dursun Özyürek ◽  
Metin Gürü

The effect of repeated quenching heat treatment on microstructure and dry sliding wear behavior of low carbon PM steel was investigated. For this purpose, atomized iron powder was mixed with 0.3 % graphite and 1 % Ni powders. The mixed powders were cold pressed and sintered at 1200°C for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at 760°C and quenched in water (single quenching). The other sintered specimens were first fully austenized at 890°C and water quenched. These specimens were then intercritically annealed at 760°C and re-quenched in water. The martensite volume fraction in the double quenched specimens was higher than that of the single quenched specimen. Wear tests were carried out on the single and double quenched specimens under dry sliding wear condition using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.


An attempt is made to find the mechanical and tribological properties of Al6061/Gr metal matrix composites (MMC) produced using stir casting method. It is important to note that the certain components require high hardness and wear resistance to fulfil the functional requirements, the said properties of the MMCs influenced largely on the condition with which they are produced or treated. Therefore, in the present paper the composites are tested in two stages that is before T6 heat treatment and after T6 heat treatment respectively. The composites are made with Al6061 alloy as matrix and graphite with 3%, 6%, 9% and 12% by wt is considered as reinforcement. Once the composites are prepared, they are examined for their microstructural, mechanical, and tribological properties. Further, a response surface methodology (RSM) has been used to model the wear loss and coefficient of friction for both before and after T6 heat treatment of MMCs. The non-linear regression model obtained is validated both statistically and with the help of experimental test cases. The evidence of wear phenomenon has been observed with the help of Scanning Electron Microscopy (SEM). Further, fuzzy grey relational Technique has been used to determine the multi performance index for the dry sliding wear and friction phenomenon of the developed composite.


Sign in / Sign up

Export Citation Format

Share Document