This paper deals with issues related to tribological processes occurring as a result of excessive wear of the surface of scraper conveyor components caused by the impact of the mined material created during drilling of development or exploitation galleries. One of the most common types of tribological wear is abrasive wear. W ear tests were carried out for hard coal – based abrasive using dry carbon abrasive and a hydrated mixture with 76 and 58% hard coal. Based on the conducted research, it was established that the effects of wear processes are associated with damage typical of wear mechanisms: micro-scratching and micro-fatigue. For the wear variant in the presence of dry coal abrasive, individual scratches caused by the abrasive grains were observed on the surface of the samples. The main reason for this type of damage was the aggregation of quartz, which is one of the basic components of the mineral substance present in the tested hard coal. When hydrated carbon mixtures were used as an abrasive, the surface of the samples also displayed scratches characteristic of the aggregate quartz. A small part of the carbon abrasive was pressed into the scratches. Under the influence of the wear caused by friction, small depressions were also formed, where coal penetrated. The effect of coal pressing into micro-scratches is related to its plastic properties. T ests of the abrasive conducted after the conclusion of wear tests have shown that under the influence of the local increase in temperature and pressure, the hard coal contained in the abrasive can undergo transformations. In the abrasive transformed under friction, small, but measurable changes in the content of the C element in relation to the initial hard coal sample were exhibited.

Poppet valves made from high-frequency heat-treated SUH3 steel have insufficient durability, and scratches appear on the valve face in prolonged use. It is necessary to develop surface treatment technology with excellent durability to prevent the deterioration of engine performance. Therefore, a surface treatment technology with higher abrasion resistance than existing processes was developed by direct metal deposition to the face where the cylinder and valve are closed. In this study, heat pretreatment and deposition tests were performed on three materials to find suitable powders. In the performance evaluation, the hardness, friction coefficient, and wear rate were measured. Direct metal deposition using Inconel 738 and Stellite 6 powders without heat pretreatment were experimentally verified to have excellent durability.