Mining machine parts restoration by laser surfacing

Introduction.The main reason for mining equipment failure is parts wearing out.Their effective repair requires advanced process flows.In the aircraft industry, for example, nickel-based alloys are widely used due to good mechanical properties.They should be considered for mining machine parts repair.Methods of research.powders were used to form coatings by laser surfacing using Optomec LENS 450 system.The adhesive strength of the deposited layer to the surface of the part, Vickers hardness (HV) and tribological properties of samples during dry sliding friction were determined.Structure was studied by the metallographic analysis with a scanning electron microscope.Research results.The adhesive force of an Inconel 718 layer deposited on 38ChMA and 42ChPhA steel is higher than that of a sample of 38ChMA plus 38ChMA and a sample of 42ChPhA plus 42ChPhA.The microhardness of the deposited layers of Inconel 718 and the part surface from 38ChMA or 42ChPhA have similar values (about 520 HV).The fracture of samples with a deposited layer of Inconel 718 is of a ductile nature, and the fracture of samples with a deposited layer of 38ChMA or 42ChPhA is of a brittle nature.The worn out surface morphology for deposited 38ChMA and 42ChPhA materials is similar. Conclusion.The possibility of repairing mining machine parts made of 38ChMA and 42ChPhA steel by laser surfacing is shown.The deposited layers of Inconel 718 alloy have good mechanical and tribological properties.The wear resistance of parts with deposited Inconel 718 material is on average 1.7 times higher than after surfacing with 38ChMA and 42ChPhA steel.