Abstract
The paper includes an assessment of the tribological properties of mineral and synthetic Lotos oil marked SAE 15W/40 and SAE 5W/40 at ambient temperature and 100 C. The evaluation was based on the analysis of the tribological properties of friction couple consumables. Tribological tests were performed using the Anton Paar THT 1000 high temperature tribotester according to ASTM G133. Tribological properties were investigated using the “ball on disc” method. The change of friction coefficient, friction couple temperature, volume wear of samples and counter-samples and Hertz stresses were evaluated. In addition, hardness tests of the friction couple materials as well as surface roughness before and after friction were performed. On the basis of tribological studies, it was noted that Lotos Synthetic 5W/40 oil has better cooling properties compared. For both oils the coefficient of friction was lower at ambient temperature than at 100 C. The highest value of volume wear of the sample was noted for the combination lubricated with Mineral Oil 15W/40 at 100 C (0.0143 mm 3 ) while for counter-sample lubricated with synthetic oil at ambient temperature (0.0039 mm 3 ). The highest sample wear coefficient was recorded for the mineral oil lubricated at temperature of 100 C (3.585*10 -7 mm 3 /N/m) while for counter-sample lubricated with synthetic oil at ambient temperature (9.8768*10 -8 mm 3 /N/m). The Hertz stress for each test couple had a value of 1.787 GPa.
Highlights
Wear of machine and equipment parts resulting from friction has always been a problem for engineers involved in the design and selection of materials for friction couples
The following conclusions can be formulated on the basis of the research carried out and the results obtained: ¥ Lotos Synthetic 5W/40 oil has better cooling properties compared to Lotos mineral oil 15W/40 tested. ¥ The average coefficient of friction for the test compounds at ambient temperature and mineral oil lubrication 15W/40 was 0.182 and when lubricated with Lotos Synthetic 5W/40 – 0.125
In temperature of 100 °C, it was 0.133 and 0.147 respectively. ¥ In the tested friction couples there was a friction wear, as proved by the traces of micro-machining and chasing on the samples surfaces. ¥ The highest value of volume wear of the sample was noted for the combination lubricated with Mineral Oil 15W/40 at 100 °C, which was 0.0143 mm3
Summary
Wear of machine and equipment parts resulting from friction has always been a problem for engineers involved in the design and selection of materials for friction couples. The elements of machines and devices parts cooperating in terms of friction work in very heavy and variable conditions This involves the use of materials of appropriate utility properties, the use of specialized surface treatment methods, lubricants and lubrication techniques. Authors of many works have confirmed that adding nanoparticles to the oil leads to improved tribological properties Nanoparticles such as carbon nanoparticles and, in particular, fullerene nanoparticles [7] diamond nanoparticles [8], nanotubes [9] and graphene nanoparticles [10,11] were introduced. The authors of this paper and the team are engaged in the development and testing of wear resistant materials [2225] In recent years, they have attempted to investigate the phenomenon of surface self-organization in the process of friction. The authors of this paper will use these oils for further research to modify and study self-organization of the friction surfaces
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
