Showing papers in "Wear in 1985"

TL;DR: Friction and wear of Si3N4 sliding on itself were measured at room temperature in different gaseous and liquid environments as discussed by the authors, showing that wear occurs by two fracture mechanisms: within 1 μm of the surface, asperity contact produces very large local stresses and cracking on a very fine scale; 3-5 μm deeper the fracture follows weaknesses of the material and is intergranular fracture with some transgranular cleavage.

TL;DR: It appears that most of the penetration of femoral heads into acetabular cups can be attributed to wear rather than to creep of the polyethylene, and the agreement between this laboratory wear factor and the deduced clinical wear factor is much better than has been recognized previously.

TL;DR: In this article, it was shown that preferential removal of the cobalt binder is an important mechanism in the abrasive wear of cemented carbides in the WC-Co family.

TL;DR: In this article, the effect of additive chain length on friction coefficient and transition temperature was investigated under different test conditions, and it was concluded that, at very low speeds, boundary lubrication is controlled by adsorbed monolayers, whereas at higher speeds, where partial elastohydrodynamic conditions prevail, ordered multimolecular layers may influence lubrication.

TL;DR: In this paper, the authors reviewed the fretting of electrical contacts on the basis of work carried out by the present author and by other investigators, including a discussion of mechanisms of transfer, wear, oxidation and frictional polymerization which apply to the fretbing of contacts and of the influence of operational parameters such as cycle rate and force on contact resistance.

TL;DR: In this article, an experimental Cr-Mo alloy rail steel was heat treated to pearlite, bainite and tempered martensite microstructure at hardness levels of 38, 42 and 45 HRC.

TL;DR: In this article, a method of choosing parameters for the multiparameter estimation of roughness is proposed, on the basis of a comparative analysis of the roughness features given by individual parameters, a selection procedure was carried out and a set of basic parameters proposed.

TL;DR: It was concluded that cement in the explanted polyethylene cups of total replacement hip joints contributed to the appearance of the worn regions and, no doubt, to the wear process itself.

TL;DR: In this article, the authors proposed that the process involved in the initial transfer events is a consequence of local shear instabilities which develop at large plastic strains. And they found that for a pin-and-disk system the disk should be made of the material having the higher cohesive strength.

TL;DR: In this article, a hot-pressed silicon-nitride-based ceramic has been used for cutting cast irons at high speeds (10−16.75 m s−1 (600−1000 m min−1) and rates (about 1.0 mm rev−1), where conventional tools cannot be used.

TL;DR: In this paper, the effect of oxide films on hot spot temperatures is deduced, and the division of frictional heat is also discussed, using an iteration process involving N, a, ξ and Tc.

TL;DR: In this paper, a model of the unsteady heat conduction process in a multidisc wet clutch embodying alternately assembled discs of two types: discs made entirely of steel and discs with a steel core lined with layers of friction material.

TL;DR: In this paper, the authors showed that the formation of α'-martensite in 304 steel gives a lower average value of friction coefficient with large fluctuations compared to 304 steel during early stages of sliding, whereas the friction continues to rise smoothly to a steady state value for 310 steel.

TL;DR: In this article, a polytetrafluoroethylene-impregnated Al 2 O 3 -TiO 2 coating on Ti-6Al-4V was evaluated against various coatings and surface treatments applied to the alloy.

TL;DR: In this paper, the machinability of an Al-40vol.%SiC composite alloy was evaluated using a large collection of experimental and commercial cutting tools, and it was observed that the wear rate of tools harder than silicon carbide was inversely proportional to their hardness.

TL;DR: In this article, a functional relationship was developed between the single-pass wear rate under severe abrasive conditions (dominated by microcracking events) and a term considering the hardness and macrofracture energy of the composites as well as a probability factor for micro-cracking.

TL;DR: Further laboratory wear studies of PTFE on stainless steel in disc machines are reported and there is excellent agreement between the mean value obtained from a variety of laboratory experiments involving environments of atmospheric air, distilled water, bovine synovial fluid and Ringers' solution with various counterface roughnesses and the wear factors derived from clinical observations.

TL;DR: In this paper, approximate solutions for the theoretical flash temperatures at circular and elliptical contact spots between two homogeneous materials when heat is evolved at the (assumed to be mathematically flat and uncontaminated) interface at a uniform rate, either independent of velocity as in the case of Joule heat or in proportion with the relative speed, i.e. as is the case for friction heat.

TL;DR: In this article, the effects of turbulent diffusion on particle dispersion, and hence on erosion, are demonstrated numerically, and the relative rate of erosion decreases and the location of maximum wear is displaced toward the stagnation point as the turbulence intensity increases.

TL;DR: In this paper, the effect of microstructure on the erosion of AISI-SAE 1078 and 10105 steels by 240 grit A1 2 O 3 particles was investigated at particle velocities V of 40-100 m s −1 and angles of impingement a of 10°-90° relative to the target surface.

TL;DR: In this paper, the authors compare the performance of two brake dynamometers, the inertial dynamometer and the Chase dynamometer, on several friction pairs under various temperature, sliding speed and load conditions.

TL;DR: In this article, an investigation of the friction and wear behavior of two commercial Fe-12%Cr-base alloys, Rex 535 and Jethete M.152, during like-on-like reciprocating sliding in air at ambient temperatures of 300-600°C has been undertaken.

TL;DR: In this paper, two-dimensional finite element calculations are used to describe the interaction between a hard rigid asperity and an as perity with an elastic-plastic material behaviour.

TL;DR: The friction and wear behavior of the graphite-fiber-reinforced glass matrix composite system is described in this paper, where both the friction coefficient and wear results are described as a function of fiber elastic modulus, fiber orientation and test configuration for unlubricated sliding.

TL;DR: In this article, the authors used thermal strain analysis to predict the lifetime of railroad wheels experiencing hot spotting, a phenomenon known as hot spotting on the tread surface as braking occurs, and calculated the thermal strains of these hot spots.

TL;DR: In this paper, an insulated, rigid, flat-ended punch moving steadily over the surface of a halfplane is considered and the effect of thermal distortion on the contact pressure distribution is found and the temperature profile under the punch is given.

TL;DR: In this article, a model was described to account for the wear rates, coefficients of friction and surface features observed when fretting a 0.64% C high tensile roping steel in seawater.

TL;DR: In this article, the effect of different modes of aeration and of pyrrhotite addition on the ball wear using mild steel, high carbon low alloy steel and austenitic stainless steel balls was evaluated.

TL;DR: In this paper, a general three-dimensional theory for thermomechanical cracking in an unflawed semi-infinite elastic medium from high speed asperity excitations is presented.

TL;DR: In this article, Japanese valve train wear engine tests were carried out using oils containing a common zinc dialkyldithiophosphate (ZnDTP) and the results showed that the zinc decomposition results in the formation of zinccontaining compounds and phosphorus-containing intermediate products such as tetraalkylthioperoxidiphosphate.