Research On Mechanical Properties And Particles Strengthening Mechanism Of Inconel718 Alloy Produced By Laser Deposition

IN718 alloy coatings and particle-reinforced IN718/WC-17Co composite coatings were prepared by laser cladding technology,and the microstructure,phase structure,EDS energy spectrum,microhardness,wear resistance,electrochemical corrosion resistance and the static mechanical tensile properties were studied,which are of great significance to the research of IN718 alloy prepared and repaired by laser cladding technology.The main work of this paper is as follows:Firstly,four process parameters with a laser power of 980W and laser scanning speeds of 6mm/s,10mm/s,14mm/s and 18mm/s were selected to prepare single-pass and multi-pass IN718 coatings.The forming situation,microstructure,XRD,microhardness,friction and wear properties of IN718 coating were analyzed under different process parameters.And the results show that when the laser power is 980W and the laser scanning speed is 14mm/s,the forming quality of the IN718 coating is better,the wear resistance is the best,and the microstructure is more refined.Secondly,selecting the optimal process parameters to prepare the IN718 alloy block,sampling the IN718 alloy block perpendicular to the laser scanning direction and parallel to the laser scanning direction,the tensile properties of the samples in two directions were tested,and the strain cloud diagrams of the tensile samples in two directions were analyzed and discussed by using the Vic-3D system.The results found that the quasi-static mechanical properties of group A（vertical）and group B（parallel）are different.The yield stress,tensile strength and elongation after fracture of group A are slightly higher than those of group B,indicating that the resistance of the group A samples to is better than that of the B group samples.Finally,composite coatings with WC-17Co content of 0wt%,10wt%,30wt%and50wt%were successfully prepared by laser cladding technology,and the effect of WC-17Co content on the microstructure of nickel-based composite coatings was studied,including phase composition,microhardness,friction and wear and electrochemical corrosion performance.The results show that with the increase of WC-17Co content,the composite coatings gradually precipitate WC,Fe₃W₃C and other hard phases,which greatly improves the microhardness and friction and wear properties of the composite coatings.However,as the content of WC-17Co increases,the corrosion resistance of the composite coatings decrease.