Application Of Ni-W-P Graphene Composite Coating On High-Speed Steel Wire Cone

As a commonly used tool steel,high-speed steel is widely used in the production of various efficient and precise tools,such as CNC cutting tools,drill bits,taps,etc.,due to its high strength,toughness,high wear resistance,and red hardness.With the continuous improvement of people’s requirements for mechanical processing efficiency,the performance requirements of cutting tools are also becoming higher and higher.To improve the service life of the tool,the solution is to add a coating on the surface of the tool,such as Ti N coating prepared using PVD technology,which can greatly improve the hardness and wear resistance of the tool edge.However,the tap prepared using this technology performs poorly in processing aluminum alloy and is prone to tool sticking.The coating prepared by chemical plating has good uniformity and can be prepared on complex surface shapes,which has been widely used in various industrial production.On the basis of Ni-W-P ternary alloy coating,graphite oxide sol with high hardness and strong self-lubricating property is added to prepare Ni-W-P-graphene composite coating,which further improves the service life of high-speed steel tools.Compare and analyze the service life of ordinary high-speed wire taps and various types of high-speed wire taps,optimize the composite coating based on the hardness and wear resistance of the coating,and optimize the bonding force between the Ni-W-P graphene composite coating and high-speed steel test blocks,achieving certain results.In order to improve the adhesion between Ni-W-P chemical coating and high-speed steel substrate,the surface activation treatment process before chemical plating on high-speed steel was mainly studied.Using four factors of different concentrations of hydrochloric acid,sulfuric acid,hydrofluoric acid,and activation time as the research objects,the binding force between Ni-W-P coating and high-speed steel substrate was used as the research index.The activator components and activation time were optimized through orthogonal experiments.Observing the surface morphology of the activated substrate through scanning electron microscopy and chemical composition detection,and measuring the bonding force between the coating and high-speed steel samples through scratch experiments to explore the relationship between activation treatment and the bonding force between the coating and substrate.Through experimental research on the optimal preparation process of electroless Ni W-P graphene composite coating,the influence of graphene content in the plating solution on the stability of the plating solution is explored;Exploring the relationship between the amount of graphene added and the hardness of composite coatings by detecting the hardness of composite coatings through microhardness testing;Detect the friction and wear performance of composite coatings using MS-T3000 ball and disc friction and wear testing machine;The nanomechanics properties of the composite coating were investigated through nano indentation test,and the relationship between the amount of graphene added and the nano hardness and elastic modulus of the composite coating was explored.The results show that the stability of the electroless Ni W-P graphene composite coating solution decreases with the increase of the amount of graphene added in the plating solution.When the graphene content in the plating solution reaches a certain concentration,the plating solution quickly fails during the plating process and cannot prepare a complete coating;The microhardness of Ni W-P graphene composite coatings prepared through experiments shows a trend of first increasing and then decreasing with the increase of graphene content.When the amount of graphene added reaches 1.00 ml/L,the maximum hardness reaches 1361.5HV;For Ni-W-P graphene composite coatings prepared with different amounts of graphene added,the friction coefficient of the coating decreases first and then increases with the increase of graphene added.Under experimental conditions,when the amount of graphene added reaches 0.75ml/L,the friction coefficient of the composite coating is the smallest;The elastic modulus of the composite coating is significantly higher than that of the coating without adding graphene.The composite coating with adding graphene has better deformation resistance,stiffness,and hardness than the coating without adding graphene.Moreover,the dispersion of graphene is relatively uniform at different indentation depths,and the microstructure of the prepared composite coating is uniform,with stable mechanical properties.Conduct tapping tests on high-speed wire taps,Ni-W-P coated wire taps,Ni-W-P graphene composite coated wire taps,and oxynitride high-speed wire taps.Under the same cutting conditions,the tool durability was tested using quenched and tempered 30CrMnSiA material.The results show that the tapping performance of Ni-W-P graphene composite coated tap is significantly better than that of high-speed wire taps,Ni-W-P coated tap,and oxynitride high-speed wire taps.