The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Recently, a low-friction effect with friction coefficients of below 0.2 against ball-bearing steel has been reported for chlorine-containing TiN coatings grown by plasma-assisted chemical vapor deposition (PACVD). This low-friction effect has been attributed to the formation of a chlorine-containing lubricant layer on top of the coating in humid air which can be regarded as a self-adaptation process...
A hard steel roller from a disc tester which had an isolated micropit and associated cracks on its surface was pressed against a glass plate and subjected to a range of lubricated, rolling–sliding conditions, with the objective of observing the effect on the distribution of film thickness in an EHL contact. The results show a remarkable interaction between the micropit, the direction of sliding and...
This paper deals with the effect of counterpart material (hardened steel, austenitic steel, and Al 2 O 3 ), internal lubricant (PTFE, graphite, MoS 2 , and SnS 2 ), and fibre reinforcement (glass and carbon fibres) on the wear of epoxy-based composites. Under dry conditions the high chromium austenitic steel led to a lower composite wear than the bearing steel. Alumina...
In this paper we propose the use of white light interferometry for measurement of wear craters on cutting tool inserts. It was briefly discussed interferometry principles and tool wear during dry metal cutting, after which a discussion of the application of interferometry to cutting tool wear measurement was described. A comparison of the profiler data with the cutting forces measured during the metal...
This paper deals with an experimental and analytical investigation into the thermodynamically activated effects influencing the behaviour of the multi-layered coated tool rake face during orthogonal cutting of ferromagnetic and paramagnetic steels. Temperature measurements on the tool rake face using a thermocouple-based technique and identification of the contact zone by means of computer image processing...
A precision positioning stage driven by ultrasonic motor (USM) with Al 2 O 3 drive tip and Al 2 O 3 driven rail has been developed for the electron beam (EB) direct-write system. Wear of a drive tip should be kept in mild wear mode for a stable precision positioning by retaining the minimum slip in the contact interface between a drive tip and a driven rail since the...
The wear analysis of an aluminium extrusion die made of Inconel 718 alloy has been performed. The highest degree of wear was observed in the middle of the contact surface with no or little wear in the adjoining regions. The wear mechanism was similar to that for steel dies and consisted in adhesive and abrasive modes. Strong adhesion of aluminium to the die led to the formation of Ni–Al–Si–Mo–Ti–Cr–Fe–Zn–O...
Surface modified (NH 4 ) 3 PMo 12 O 40 nanoparticles were synthesized in a mixture solution of water–ethanol with cetyltrimethyl ammonium bromide as a modifying agent. The morphology, structure and thermal properties of modified (NH 4 ) 3 PMo 12 O 40 nanoparticles were investigated by means of transmission electron microscopy, X-ray powder...
The two kinds of kaolin filled ultra-high molecular weight polyethylene (UHMWPE) based composites (UHMWPE/kaolin) were prepared by means of polymerization filling and melt mixing, respectively. The unlubricated sliding wear behavior of the composites was tested on an MM200 rig. The effects of sliding speed and load on the sliding wear of UHMWPE were determined. Scanning electron microscopy (SEM) was...
The properties of ceramics, specifically low density and high stiffness are of most interest to gas turbine and machine tool manufacturers. High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Much research over the past two decades on its structure, quality control and manufacturing techniques has produced ceramic...
Corrugated steel moulds, so-called ‘gliders’ used to shape, densify and burnish concrete roof tiles are subject to severe abrasive sliding wear caused by the action of hard quartz grains in the moving concrete mass. Hard surface coatings based on tungsten carbide (WC) applied to the gliders are thought to reduce substantially the friction between concrete slab and forming tool and hence the loss of...
Scuffing failure was induced in samples of SAE 4340 steel which had been quenched and annealed at several temperatures. Examination of worn areas using grazing-incidence X-ray diffraction revealed an austenitic phase at volume fractions of up to 60%. No dependence of austenite fraction on depth was observed for depths of up to 5.0μm. No clear trend in austenite fraction after scuffing as a function...
Centrifugal pumps, with impellers and discs made of a stainless duplex steel, were tested for 11 weeks in a recirculation loop of a sewage plant. One pump was equipped with solution annealed (SA) components the other with solution nitrided (SN) ones. The surface of the latter was enriched with nitrogen in solid solution, which transformed the ferritic grains into austenitic ones and raised the hardness...
The influence of metal oxide additives within alumina (α-Al 2 O 3 ) and yttria-stabilised tetragonal zirconia (Y-TZP) matrices was studied with respect to the tribological behaviour of the composites. The solid lubricants CuO, ZnO, MgO, MnO 2 and B 2 O 3 were added in sufficiently small quantities (1 or 5wt.%) to preserve the mechanical properties of the matrix...
Influence of fabric reinforcement in polymers is well investigated in the unidirectional sliding wear mode leading to adhesive wear of the composites, but not in the case of low amplitude oscillating (fretting or reciprocating) wear mode. In the authors’ laboratory, series of polyetherimide (PEI) composites reinforced with fabrics of carbon and glass were investigated in this respect. In this paper,...
The purpose of this investigation was to characterize the dependence of paper-to-paper friction on the sliding direction of the previous slide for various paper grades. Static and kinetic friction forces and coefficients of friction were measured using a friction tester based on the horizontal plane principle. The papers were also characterized with respect to fiber-rising tendency and they were imaged...
The oscillating wear failure of the materials is frequently observed in various tribo-applications such as bearings, gears, bushes, palliatives, bolted and riveted joints and seals, etc. where oscillations of small amplitude or vibrations are inevitable. In general, the oscillating wear performance of the materials depends on the amplitude of oscillation, its frequency and duration, load, contact...
Subsurface damage in scratch tests has been investigated to highlight the relationship between damage characteristics and mechanical response of materials, such as the tangential force F t . A progressive loading tester with a spherical indenter, on which the normal load F n was increased with increasing sliding distance, was utilized for tests on a commercially available hot-pressed...
The objective of this study was to develop high-quality grinding protocols for polycrystalline silicon carbide spherical surfaces in order to achieve nanometre surface roughness and submicron form accuracy. Plastic deformation and fracture damage associated with the material removal mechanisms were studied using nano-indentation and Vickers indentation. Spherical grinding was conducted with a CNC...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.