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We have created inorganic-organic hybrid composites and antibiocorrosive coatings based on an epoxy modified with silicon-containing polyepoxies and bioactive coordination compounds. The scratch resistance was determined using a conical diamond indenter with linearly increased load. Repetitive scratching along the same groove (sliding wear determination) was also performed. Whether in single or in...
The concept of the rail damage function provides vital understanding of the operational performance of rail grades in terms of surface degradation. The present study extends this concept from conventional to premium pearlitic rail. This is done on the basis of both simulations of dynamic train-track interaction and field observations. Rolling Contact Fatigue (RCF) damage index values for the conventional...
The erosion resistance of infrared optical windows was studied experimentally using ice particles of 2mm diameter. Single ice particles were accelerated to approximately Mach 4.7 using a two-stage light gas gun. Sapphire and zinc sulfide infrared optical windows were tested. The windows were impacted repeatedly until a linear or circumferential crack was found. From the normal impact tests, it was...
Aluminium alloys are commonly used for the production of components, such as cylinders, pistons, pumps, valves and combustion chambers, which in service may incur in cavitation phenomenon.In the present paper, the cavitation erosion resistance of an innovative light-alloy used for Hybrid Aluminium Forging was investigated. The material was tested by means of an ultrasonic vibratory device in compliance...
The tribological behaviours of two seal coatings (NiAl-hBN and Al-hBN) against Ti-6Al-4V blade were investigated under high-speed rubbing conditions by a self-developed tribology tester. The wear behaviour and the mechanism of the blades and seal coatings were studied. The maximum possible temperature (MPT) and the temperature rising rate (TRR) at the rubbing surface, which were both directly related...
The objective of this paper is to investigate the roles of thread wear on self-loosening behavior of bolted joints subjected to transverse cyclic loading. A fatigue test machine was used to apply the transverse displacement to the bolted joints during the self-loosening test. Finite element analysis was conducted to investigate the influence of preload and thread locker on the self-loosening from...
The purpose of this investigation was to determine the extent to which a combination of electron beam melting and specific machining procedures could improve the wear resistance of acetabular cups for hip implants. Electron Beam Melted Ti6Al4V samples, with a simplified geometry close to that of acetabular cups, were finished by machining. Wet and cryogenic machining with a different number of finishing...
Three-body abrasive wear of 0.2wt%-C martensitic steel was conducted in a dry-sand rubber wheel test apparatus following non-standard G65-16 test procedure. The specific wear rate (SWR) of the experimental alloy was compared against other microstructures of equivalent hardness. It was observed that the SWR of the experimental alloy follows the Type-1 category, in which hardness plays a major role...
An experimental study on the cavitating jet was conducted with emphasis placed on the detection of the energy that is emitted by the collapse of cavitation bubble. Four experimental methods, each respectively utilizing a hydrophone, an acoustic emission (AE) sensor, a laser Doppler vibrometer, and a polyvinylidene fluoride (PVDF) sensor, were compared. Aluminum specimens served as the target that...
In this study, we focus on the ultra fine particulate matter emission of rubber tires and investigate it with the inner drum tire test bench of the Karlsruhe Institute of Technology. We examine if a tire emits particulate matter and explore under which running conditions it emits most significantly. We concentrate on the emission of ultra fine particulate matter with an aerodynamic diameter between...
This work studies FeVCrC-based coatings as potential alternatives to conventional Ni- and Co-based alloys for wear protection. Specifically, the microstructure and tribological properties of the coatings are characterized as a function of the particle size distribution of the feedstock powder, of the deposition technique – High Velocity Oxygen-Fuel (HVOF) or High Velocity Air-Fuel (HVAF) spraying...
Mathematical models suggest that the strain along the film formed by parallel passes of a nanoindentation probe in contact with the film can be either homogenous or heterogeneous, depending on contact pressure and spacing between passes. In this study, a 1µm copper thin film was worn with a cono-spherical diamond probe with normal loads ranging from 25 to 800µN and wear box edge lengths of 40, 60,...
The visualization of wear depth in hip prostheses can assist the evaluation of new bearing materials and implant designs. The goal of this study was to develop an accurate, fast, and economical methodology to generate colorimetric maps of wear depth in hip implants using a structured light 3D optical scanning system. The accuracy and precision of this novel technique were determined using reference...
This study presents the wear and damage behaviours of U71Mn rail material with a friction pair of ER8 wheel material under different temperature conditions, which were explored using a rolling-sliding wear testing device. It turns out that, compared to those at 20°C room temperature, the adhesion coefficient, wear rate and hardness all increase at low temperatures. Meanwhile, three types of damage...
Size effect of rubber particles on the friction and wear of brake friction materials was investigated since their morphology is often connected to friction instability. Friction materials were fabricated with recycled rubber particles of two different sizes, approximately 75 and 450µm, and their frictional performance was examined with a reduced-scale brake dynamometer. The results showed that the...
WC cemented carbides are used extensively as cutting and drilling tools in the cutter heads of the full face Tunneling Boring Machines (TBMs).This paper describes the effects of microstructural properties of selected cemented carbide grades, operating as cutting tools in dry and foam conditioned soil, towards abrasive wear resistance. The work was carried out with the purpose of identifying the most...
The purpose of this work was to improve reliability and durability of high-silicon aluminum alloy piston skirts for diesel engines. Novel ceramic matrix composites were fabricated on ZL109 aluminum alloy substrates by two steps combining microarc oxidation (MAO) with electrophoresis deposition (EPD). MoS2 is incorporated into an aluminum oxide matrix during processing. The effects of the ceramic matrix...
As a particular important factor in UltraSonic Machining (USM), the tool wear largely affects the material removal process and accordingly influences the machining performance. Although a number of experiments were conducted to monitor and measure the tool wear during USM in previous works, the nature of the tool wear mechanism and its relation to material removal have not been totally understood...
Computational Fluid Dynamics (CFD) based erosion prediction procedures are carried out to predict erosion for a submerged liquid jet impingement geometry. 3-D modeling with different near wall treatments are employed to simulate the wall bounded turbulent jet flow. Discrete Phase Model (DPM) is applied to track particles and obtain particle impact characteristics. Erosion is calculated using typical...
Several components in the oil and gas industry are subjected to wear and corrosion. This work evaluated the feasibility of using Diamond-Like Carbon (DLC) coatings in Subsea Safety Control Valves (SSCV), piston and pumps. These are made from API X65 carbon steel and are subjected to wear and corrosive/saline environments. Coatings were deposited using Plasma Enhanced Chemical Vapour Deposition (PECVD)...
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