An Experimental Investigation of the Effect of Lubricant Properties on Temperature and Wear in Sliding Concentrated Contacts

1981 ◽  
Vol 103 (2) ◽  
pp. 261-265 ◽  
Author(s):  
A. Seireg ◽  
E. Hsue

The study reported in this paper is undertaken to investigate the effect of some of the physical properties of lubricants on the contact temperature and wear in heavily loaded Hertzian Contacts under sliding conditions. The surface temperature and wear in a rotating mild steel shaft are measured under different loads applied by a Tungsten Carbide slider. The carbide tip and the shaft are used as part of a dynamic thermocouple system to monitor the contact temperature. Tests are conducted for Hertzian pressures ranging from 1250 to 2140 MPa (1.81×105–3.10×105 psi) and sliding speeds from 0.4 to 1.3 m/sec (943–3142 in./min). Temperature and wear data are given from tests with a heavy duty oil (SAE 80W-90), a high viscosity residual compound, a vegetable oil, and water miscible cutting fluid (0.0476 percent emulsifiable oil by volume). The results show that, for the considered tests, viscosity does not appear to be the significant property of the lubricant temperature rise and wear rate as indicated by the scar depth under similar test conditions.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3074
Author(s):  
Kaveh Torkashvand ◽  
Vinod Krishna Selpol ◽  
Mohit Gupta ◽  
Shrikant Joshi

Sliding wear performance of thermal spray WC-based coatings has been widely studied. However, there is no systematic investigation on the influence of test conditions on wear behaviour of these coatings. In order to have a good understanding of the effect of test parameters on sliding wear test performance of HVAF-sprayed WC–CoCr coatings, ball-on-disc tests were conducted under varying test conditions, including different angular velocities, loads and sliding distances. Under normal load of 20 N and sliding distance of 5 km (used as ‘reference’ conditions), it was shown that, despite changes in angular velocity (from 1333 rpm up to 2400 rpm), specific wear rate values experienced no major variation. No major change was observed in specific wear rate values even upon increasing the load from 20 N to 40 N and sliding distance from 5 km to 10 km, and no significant change was noted in the prevailing wear mechanism, either. Results suggest that no dramatic changes in applicable wear regime occur over the window of test parameters investigated. Consequently, the findings of this study inspire confidence in utilizing test conditions within the above range to rank different WC-based coatings.


2020 ◽  
pp. 146808742093016
Author(s):  
Onur Biyiklioğlu ◽  
Mustafa Ertunc Tat

Internal combustion engines consume about 90% of fuel refined from crude oil which supplies 30% of the annual global flow of energy. Heavy-duty diesel engines are the primary source of power used in highways, marine, railroads, and power stations. The right coating can improve the tribological properties of cylinder liners and increase the mechanical efficiency of an engine. Also, it can help to extend the maintenance periods, and enhance the reliability of the vehicles. In this research, tribological and economic evaluations were performed for coated and uncoated substrates from a cylinder liner of a heavy-duty diesel engine, aiming to lower friction, wear rate, and maintenance cost. A reciprocating friction test was conducted under dry condition using Wolfram carbide (tungsten carbide) ball applied a 10 N normal load on a ball on disk geometry. The cylinder liner was made of gray cast iron, and the substrates obtained were coated with three different coating materials (Cr3C2/NiCr, NiCr, and Al2O3/TiO2) through the thermal spray and high-velocity oxy-fuel coating process. Tribological evaluations showed that the substrates coded with Al2O3/TiO2 and Cr3C2/NiCr had the lowest friction coefficient and wear rate. The most economical coating was Al2O3/TiO2, being able to supply about 61% lower coefficient of friction and 94% less wear rate relative to the uncoated sample, for the price of one-third of the Cr3C2/NiCr coating and one half of a new gray cast iron cylinder liner.


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