scholarly journals Investigation on Speed-Load Sensitivity to Tribological Properties of Copper Metal Matrix Composites for Braking Application

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 889
Author(s):  
Yelong Xiao ◽  
Pingping Yao ◽  
Haibin Zhou ◽  
Zhongyi Zhang ◽  
Taimin Gong ◽  
...  

A sensitivity analysis of braking speed and normal load on tribological properties of copper metal matrix composites (Cu-MMCs) was investigated using a subscale dynamometer. The morphologies of the worn surface and subsurface were observed by a scanning electron microscope and 3D video microscope. The results indicated that temperatures on the Cu-MMC surface increased with increasing the braking speed and normal load. The average coefficient of friction gradually decreased as the braking speed or normal load increased, and a slight decrease in the wear rate with increasing the braking speed up to 17 m/s after which a clear increasing trend was observed. As the normal load increased from 612 N to 1836 N, the wear rate decreased firstly and then promptly decreased. The transition in wear mechanism of Cu-MMC significantly depended on braking speed and normal load.

Author(s):  
Naseem Ahamad ◽  
Aas Mohammad ◽  
Kishor Kumar Sadasivuni ◽  
Pallav Gupta

The aim of the present work is to investigate vickers hardness, wear behavior as well as to perform optimization of wear data for pure Al and Al-Al2O3-TiO2 hybrid metal matrix composites. The hybrid composite (Al-Al2O3-TiO2) was prepared by mechanical stir casting with equal proportion of reinforcement (2.5, 5.0, 7.5 and 10 wt.%). Vickers hardness, wear behavior and its optimization using ANOVA as well as TOPSIS along with the microstructure of the worn surface of prepared sample has been investigated. Vickers hardness increases with an increase in weight percentage of reinforcements. Wear test was carried out under dry sliding condition by pin-on-disc wear machine according to the ASTM G99-95a standard. Wear properties of the sample have been obtained at different percentages of reinforcement. Wear resistance of the hybrid composite increases with the variation of percentage of titanium oxide particles due to its lubricating properties. ANOVA shows that the reinforcements and load have different effect on samples wear rate. TOPSIS analysis shows rank of the sample according to its wear rate. Worn surface morphology was investigated and it showed deep grooves, more debris, delamination and rough surface in pure Al sample as compared to the high percentage of reinforced hybrid metal matrix composites.


2019 ◽  
Vol 138 ◽  
pp. 380-391 ◽  
Author(s):  
Haibin Zhou ◽  
Pingping Yao ◽  
Taiming Gong ◽  
Yelong Xiao ◽  
Zhongyi Zhang ◽  
...  

2018 ◽  
Vol 6 (1) ◽  
pp. 016549 ◽  
Author(s):  
Nalin Somani ◽  
Y K Tyagi ◽  
Parveen Kumar ◽  
Vineet Srivastava ◽  
Hiralal Bhowmick

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3110
Author(s):  
Kaveripakkam Suban Ashraff Ali ◽  
Vinayagam Mohanavel ◽  
Subbiah Arungalai Vendan ◽  
Manickam Ravichandran ◽  
Anshul Yadav ◽  
...  

This study focuses on the properties and process parameters dictating behavioural aspects of friction stir welded Aluminium Alloy AA6061 metal matrix composites reinforced with varying percentages of SiC and B4C. The joint properties in terms of mechanical strength, microstructural integrity and quality were examined. The weld reveals grain refinement and uniform distribution of reinforced particles in the joint region leading to improved strength compared to other joints of varying base material compositions. The tensile properties of the friction stir welded Al-MMCs improved after reinforcement with SiC and B4C. The maximum ultimate tensile stress was around 172.8 ± 1.9 MPa for composite with 10% SiC and 3% B4C reinforcement. The percentage elongation decreased as the percentage of SiC decreases and B4C increases. The hardness of the Al-MMCs improved considerably by adding reinforcement and subsequent thermal action during the FSW process, indicating an optimal increase as it eliminates brittleness. It was seen that higher SiC content contributes to higher strength, improved wear properties and hardness. The wear rate was as high as 12 ± 0.9 g/s for 10% SiC reinforcement and 30 N load. The wear rate reduced for lower values of load and increased with B4C reinforcement. The microstructural examination at the joints reveals the flow of plasticized metal from advancing to the retreating side. The formation of onion rings in the weld zone was due to the cylindrical FSW rotating tool material impression during the stirring action. Alterations in chemical properties are negligible, thereby retaining the original characteristics of the materials post welding. No major cracks or pores were observed during the non-destructive testing process that established good quality of the weld. The results are indicated improvement in mechanical and microstructural properties of the weld.


Author(s):  
Arabinda Meher ◽  
Manas Mohan Mahapatra ◽  
Priyaranjan Samal ◽  
Pandu R. Vundavilli

In the present study, the statistical analysis on tribological behavior of RZ5/TiB2 magnesium-based metal matrix composites is carried out using Taguchi design and analysis of variance (ANOVA) technique. Taguchi analysis using signal-to-noise ratio indicates that the sliding distance and wt.% TiB2 are the most significant factors in evaluating weight loss and coefficient of friction, respectively. The regression equation is formulated utilizing the ANOVA technique to study the output responses based on the input abrasive wear test experimental results. The regression equation is validated through a comprehensive study taking a series of abrasive wear tests and indicates the percentage deviation of regression modeling is in the range of ± 10%. The individual and combined effect of wear parameters on tribological behavior are investigated through the main effect plots and response surface plots. The micrograph of the worn surface of RZ5/TiB2 composites is studied using field emission scanning electron microscope (FESEM), indicating the formation of an oxide layer on the worn surface.


Author(s):  
Theerkka tharaisanan Rajamanickam ◽  
Kathiresan Marimuthu

Aluminium metal matrix composites (AMMC’s) have been widely used because of their superior properties like high strength to wear ratio, high wear resistance, and higher heat conduction rate. The additions of reinforcements in the form of discontinuous particles lead to an increase in the properties of Metal Matrix Composites (MMC). In this present work, the ALMMC composite was fabricated with the addition of discontinuous reinforcement particles of Zirconium Carbide (ZrC) and Boron Carbide (B4C). The mechanical properties such as tensile strength, hardness, and impact strength were tested as per the ASTM standards. The tribological properties were tested using a pin-on-disc setup under different loading conditions (10, 20, 30, 40 N). Moreover, the morphological characterization of ALMMC was carried out by using the Scanning Electron Microscope (SEM) analysis. Furthermore, the Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA) was accomplished to find the thermal stability of ALMMC. The findings show that the variations of reinforcement of ZrC added had given improved properties like hardness, tensile strength, impact strength and wear resistance.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2892 ◽  
Author(s):  
Grzegorz Królczyk ◽  
Eugene Feldshtein ◽  
Larisa Dyachkova ◽  
Mariusz Michalski ◽  
Tomasz Baranowski ◽  
...  

In this paper, the features of the strength, fractures, and tribological behavior of metal-matrix composites based on the FeGr1 material are discussed. To improve the material properties, a mixture of SiC, Al2O3 and C nanoparticulates have been added to an iron-based matrix. The simplex lattice design method and hardness, compression, and bending tests were used to determine the mechanical properties. Scanning electron microscopy was applied for fracture features analysis. Different fracture types, mainly trans-crystalline quasi-brittle and brittle fracture or inter-granular fracture and microcracks were registered for the composites tested. Depending on the type and amount of ceramic additives, significant changes in strength, as well as in the fracture features of the metal-matrix composites (MMCs), were observed. Based on tribological tests, changes in the momentary coefficients of friction, temperature of the friction surface, and wear rate of the composites with nanoparticulates were described. An analysis of the worn surface morphology revealed changes in the wear process depending on the MMC composition. It was shown that the use of hybrid mixed additives based on hard ceramic nanoparticulates improved both strength and tribological properties of composites.


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