Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine

Abstract

The present paper analyzes the damage of surfaces at spots of frictional contact, namely, the friction nodes on a camshaft and the connecting rod pins of a crankshaft. The resulting wear of the monitored friction nodes reduces the technical life of the machines, which can lead to the decommissioning of the machine. Wear was assessed by measuring roughness and microhardness and by observing the microstructures of the materials. The results of the experiments show that the rotating parts displayed visible wear on the cams, as well as on the connecting rod pins. The experiments revealed that wear was caused by the heating of the material to a high temperature during the operation of the machine and that there was a gradual cooling and tempering of the material, which led to a reduction in the microhardness of the monitored object. Lower microhardness values can be a cause of greater wear of the monitored objects. When comparing the microhardness of the used and the new camshaft, the hardened layer of the new camshaft from secondary production has a significantly smaller thickness compared to worn cams, which leads to the finding of a different material quality compared to the original parts from primary production. This fact indicates that the wear of a new camshaft as a spare part can contribute to the shortening of the technical life of friction nodes.

Structural and energetic self-organization of antifriction composite materials of car parts during friction and wear

“…Solving the problem of increasing the tribological reliability and durability [1,2] of tribocoupled elements of car parts requires a comprehensive approach [3]. This includes: the following measures: development of modern research methods and kinetic criteria for evaluating processes in the zone of frictional contact; creation of new antifriction composite alloys; methods of controlling the surface strength of materials during friction and wear [4,5].…”