Improvement in surface properties and retainment of bulk properties are essential requirements for the design of components for wear resistance applications. This paper summarizes various features of Al/SiC/Gr hybrid composites that can be employed in different tribological applications. The study has revealed that the processing route plays a significant role in obtaining a homogeneous structure of these composites. In powder metallurgy, the selection of sizes of the matrix and reinforcement...

Lasma-sprayed thermal barrier coatings (TBCs) are gaining wide popularity and becoming more attractive for many industrial applications due to their high strength, thermal barrier/fatigue characteristics at elevated temperatures, resistance to chemical degradation, wear resistance, and environmental corrosion protection provided when coated on the surface of engineering components. To characterize the tribological properties of TBCs, a better understanding of their failure mechanisms and a th...

In this work, we developed a finite element modeling approach to study adhesion during unidirectional contact between a two-dimensional plane-strain square and a flat slab. The surfaces were metallic or ceramic, and we analyzed different pairs of materials and their adhesion intensity using a FORTRAN subroutine (DLOAD) connected to a commercial finite element code Abaqus, which provided the surface attractive forces based on the Lennard-Jones interatomic potential using Hamaker constants. We ...

High temperatures appear in the contacting surfaces of a single-disc clutch system (friction clutch disc, flywheel and pressure plate) due to the relative motion between these parts during the sliding period. These high temperatures are responsible for several disadvantages such as increasing wear rate, surface cracks and permanent distortions. In some cases, these disadvantages may lead the contacting surfaces to failure before the expected lifetime. In this work, mathematical models of the ...

The objective of this study was to investigate the influence of the surface topography on the tribological behavior of the wheel/rail contact. Four different groove orientations forming the surface topographies—smooth surface, 0°, 45° and 90°—were manufactured by grinding and compared. All friction tests with different surface topographies were conducted using an alternative tribometer simulating the pure sliding process in the wheel-rail contact. The Hertzian pressure was maintained at 1,000...

Understanding the wetting behavior of nanostructures is important for surface design. The present study examined the intrinsic wettability of nanopore structures, and proposed a theoretical wetting model. Using this model, it was found that the wetting behavior of nanopore structures depends on the morphology of a surface. To accurately predict the wetting behavior of nanopore structures, correction factors were introduced. As a result, the proposed wetting model can be used to predict the we...

In order to increase the life of spacecraft, it is important to improve the comprehensive lubrication performance. Multiple alkylated cyclopentane (MAC) lubricants are presently gaining wide acceptance for actual space applications; adding extreme pressure additive is a strategy to improve lubrication performance. In this study, taking 1,3,4-tri-(2-octyldodecyl) cyclopentane as base oil, tricresol phosphate (traditional additive) and tri-(2-octyldodecyl) phosphate (developmental additive) hav...

The purpose of this research is to investigate the validity of the Reynolds equation in spool valve analysis under cavitation. This study is carried out for a laminar and isothermal flow between a sleeve and spool with grooves. The pressure and lateral force obtained from the Reynolds equation and the Navier-Stokes equation are compared with variations of aspect ratio, cross sectional area, and number of grooves. The cavitation phenomenon is considered by using a cavitation model in the Navie...