Tribological Properties of Metal Matrix Composites

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.

Download Full-text

Experimental investigation of Mechanical and Tribological Properties of Al6061-ZrC-B4C Hybrid Composites

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2020-0137 ◽

2020 ◽

Author(s):

Theerkka tharaisanan Rajamanickam ◽

Kathiresan Marimuthu

Keyword(s):

Tensile Strength ◽

Wear Resistance ◽

Impact Strength ◽

Metal Matrix Composites ◽

Tribological Properties ◽

Metal Matrix ◽

Hybrid Composites ◽

Zirconium Carbide ◽

High Wear Resistance ◽

Matrix Composites

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.

Download Full-text

On the Microstructure, Strength, Fracture, and Tribological Properties of Iron-Based MMCs with Addition of Mixed Carbide Nanoparticulates

Materials ◽

10.3390/ma13132892 ◽

2020 ◽

Vol 13 (13) ◽

pp. 2892 ◽

Cited By ~ 1

Author(s):

Grzegorz Królczyk ◽

Eugene Feldshtein ◽

Larisa Dyachkova ◽

Mariusz Michalski ◽

Tomasz Baranowski ◽

...

Keyword(s):

Metal Matrix Composites ◽

Tribological Properties ◽

Metal Matrix ◽

Design Method ◽

Matrix Composites ◽

Wear Process ◽

Lattice Design ◽

Friction Temperature ◽

Iron Based ◽

Fracture Features

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.

Download Full-text