Study On Surface Treatment Of Aluminum Alloy Wheel Hub Based On Abrasive Water Jet

Abrasive water jet technology has unique advantages in surface treatment.It has been widely used in various industries.This thesis launches the research work on surface treatment of aluminum alloy wheel hub using abrasive water jet.The erosion effect of abrasive particles in surface treatment processing was also analysised.At the same time,the mechanism of materials removal by abrasive water jet was researched.Through the analysis of the velocity field of jet,the main section of water jet is suitable for remove of the smaller amount of material.The plastic deformation and brittle fracture by high-speed abrasive particles and the mechanism of material erosion was analysised based on indentation fracture model and single abrasive particle approximation cutting model,.Theoretical results show that the erosion depth is smaller while the normal load decreases and the surface quality is better.The simulation of the velocity distribution field of abrasive water jet on the curved surface and plane surface using Fluent software was carried out.Results show that velocity distribution of the curved surface and plane is similar.The kinetic energy of the initial section jet is higher.And the energy exchange among the around of jet border and around medium of body section exists.The distribution field of Static pressure on the workpiece surface shows that when the jet pressure increases,the shearing action of water jet was enhanced.Different shapes of surface have the maximum impact static pressure at the point of impact.With the increase of wall radial distance,the pressure decreases rapidly.The simulation of distribution field of the jet shear stress on workpiece surface shows that there is a regular circle distribution for the surface shear stress.For the curved surface,shear stress changes greatly.And it has the irregular symmetrical distribution in curved surface in generatrix and radial direction of the impact point circumferential.The effect of each parameter on quality of surface treantment of aluminium alloy specimen,such as jet pressure,abrasive size,standoff distance,jet angle was studied.The results show that surface roughness of the workpiece increases when the the jet pressure is increased.This is because abrasive particle collision with workpiece and shear stress were enhanced.The workpiece surface roughness and material removal rate increases at the beginning and then decrease when the jet angle was increased.There is a optimal angle of25°.When the standoff distance was increased,the workpiece surface roughness and material removal rate increases firstly then decreases.There is an optimal standoff distance of 20 mm.While the abrasive particle size was decreased,surface roughness of workpiece and material removal volume are generally decreased.The effect of parameters,such as jet pressure,abrasive size,standoff distance,jet angle on surface roughness and material removal rate was studied using orthogonal experiment andrange analysis.Results show that the primary and secondary influences order on surface roughness are standoff distance,jet angle,jet pressure,abrasive particle size.The primary and secondary influences order on material removal volume are jet pressure,standoff distance,jet angle,abrasive particle size.Using multivariate regression analysis,the empirical model for the surface roughness and material removal rate and the process parameters is established.The verification results were within the accepted error range.It can be used to predict and control the.surface treatment of aluminum alloy wheel hub.