The Research On Process Optimization And Properties Of Laser Cladding Ironbased Coatings Prepared Using Powders With Different Diameter

Iron-based alloy powders have been widely used in laser cladding production due to their low price and high hardness.At present,most researchers have achieved the purpose of strengthening coating by adding different components to iron-based powders.In this paper,three kinds of iron-based TZ625 powders with different diameter were selected.Different cladding layers were prepared on the 45 steel substrate by laser cladding technology.The influence of powder diameter on the microstructure and mechanical properties of the iron-based alloy coating was studied in depth.The iron-based TZ625 powder with an average particle diameter of 37?m was used as the cladding powder with 45 steel as the substrate,and the laser cladding process was studied.The experiment takes the preset powder thickness and laser cladding power as variables,The friction and wear properties and mechanical properties are the evaluation indexes.The study found that the coating surface has the highest microhardness when the preset powder thickness is 2.0mm,the laser cladding power is 3100W;the average friction coefficient of the coating is the smallest when the laser cladding power is 3000 W,The preset powder thickness is 1.5mm,and the friction curve fluctuation range is also small;the impact toughness decreases with the increase of the preset powder thickness.Using the optimized process parameters,the laser cladding layer was prepared on the 45 steel substrate with iron-based TZ625 powder with average particle diameter of 100?m,37?m and 19?m.The microstructure of different powder diameter coatings was analyzed.The results showed that the microstructure of the coating with a powder diameter of 100?m is mainly austenite,and the hard phase content is less.The microstructure of the 37?m coating is mainly austenite of the cell morphology,and the hard phase is formed at the grain boundary.Distribution of the shape;the microstructure of the 19?m coating is mainly fine dislocation martensite.Microhardness,friction and wear performance and impact performance of different powder particle diameter coatings is analyzed.The 37?m coating has the highest microhardness.The 19?m coating friction curve has a very small fluctuation range,and the average friction coefficient is 0.29,which is much smaller than 100?m coating and 37?m coating;according to the particle particle diameter from small to large,the wear modes are slight adhesive wear,adhesive wear and severe peeling wear;the coating with a powder diameter of 19 ?m has the best impact toughness.