Abrasive wear resistance of Fe ₃ Al and Stellite 6 coatings for the protection of valve faces

Developing a technology that increases the service life of valve seats in CNG/LNG-powered vehicles requires the appropriate selection of material and its application technology. Commercially used valve seat materials show accelerated wear under operating conditions, especially in natural gas vehicle engines. The authors developed a new material and technological concept to protect the valve seat in CNG/LNG-powered vehicles. Two materials were used in the research: Stellite 6 alloy and Fe₃Al intermetal. A commonly used material for valve seats of combustion engines is Stellite 6. The Fe₃Al is the new proposed material coating for the protection of the valve seats of internal combustion engines. The article compares the abrasive wear resistance of these materials. The abrasion tests were performed on a T-11 pin-on-disc tester, and the counter-sample was steel S235JR. The test conditions were similar to those prevailing during the operation of the valves in the head of the internal combustion engine, without the influence of temperature. The results indicate that the Fe3Al intermetallic compound is characterised by a lower coefficient of friction and wear intensity than Stellite 6. The results of exploitation tests confirm that the Fe₃Al phase is a prospective material to be used as a protective material on the valve seat of vehicles. The authors made a mathematical model for the wear of the newly created surface layers and proposed hypotheses regarding the wear mechanisms of these layers.