Industrial Lubrication and Tribology

R. Fuentes; E. Rubio; C. Gómez; A. Herrera; V.M. Castaño

doi: 10.1108/00368790310480344pmid: N/A

The wear behavior of a novel composite aluminum‐graphite composite prepared by simple powder metallurgy techniques is reported. Graphite powders were surface‐treated with copper to activate the powder surface and to improve the wettability of the graphite surface. The mixed Al‐C (7 percent, 5 percent, 3 percent, 1 percent y 0.5 percent C weight content) powders <100 μ m were pressed at room conditions and then heat‐treated at 600°C. The tests showed improvements in wear resistance as the graphite content decreases, achieving the optimal behavior at 1 percent content.

Hakan Kaleli

doi: 10.1108/00368790310480353pmid: N/A

Two 5W‐30 synthetic‐base phosphorus containing (commercial) and phosphorus‐free (P‐free) crankcase oils were tested for engine performance characteristics, engine emissions and poisoning effects of oil additives on a three‐way catalytic converter using engine dynamometer. The emission data of the two oils taken during engine operation were compared in the absence and presence of the catalytic converter. Surface characterization was used to determine the poisoning catalyst effect accumulated from the oil additives in the ceramic washcoat. Oil analyses were also used to examine the condition of the lubricant occurred during engine performance testing operation. The experimental engine performance tests indicated that the catalytic converter diminished the torque and power for the commercial and P‐free oils, whereas the specific fuel consumption increased for both oils in the presence of the catalytic converter.

H. Unal; A. Mimaroglu

doi: 10.1108/00368790310480362pmid: N/A

The tribological problems of polymers have received more attention because of their suitability for fabricating machine elements in food industry, which require self lubrication environment. In this investigation, we studied and explored the influence of test speed and load values on the friction and wear behaviour of PTFE, POM and PEI polymers. Friction and wear tests of PTFE, POM and PEI vs steel were carried out at dry condition on a pin‐on‐disc arrangement. Tribological tests were carried out at room temperature, under 5, 10 and 15 N loads and at 0.5, 0.75 and 1 m/s speeds. The specific wear rates were deduced from mass loss. The results showed that, for all the polymers used in this investigation, the coefficient of friction increases linearly with the increase in load. Moreover, for the load and speed range of this investigation, the wear rate showed very little sensitivity to the applied load and large sensitivity to test speed, particularly at high load values.

N.B. Naduvinamani; Syeda Tasneem Fathima; P.S. Hiremath

doi: 10.1108/00368790310480371pmid: N/A

In the present paper, the squeeze film lubrication between anisotropic porous rectangular plates with lubricants containing polar additives has been studied. The lubricants containing additives has been modelled as a Stokes couple stress fluid. The more realistic Beavers‐Joseph slip boundary conditions are used to derive the most general form of Reynolds equation, which account for the effects due to the lubricant additives and the anisotropic nature of porous material. The eigen type of expressions are obtained for the fluid film pressure, load carrying capacity and squeeze film time. It is observed that the effect of the lubricant additives is to increase the load carrying capacity and the squeeze film time as compared to the Newtonian lubricants. Further for anisotropic porous surface, the maximum load carrying capacity is attained for the rectangular (non‐square) plates.