Numerical Simulation And Experimental Study On Surface Treatment Of Dental Implants Under Abrasive Water Jet

As an advanced technique in the repair of tooth defects,dental implantation has been widely used in the medical field.Titanium and titanium alloys have the advantages of good mechanical properties,low density,low toxicity and good biocompatibility.It is an ideal metal material for oral implants.In order to make titanium and titanium alloy have better compatibility with the human environment and replace the original ineffective tissue to play a role,it is necessary to conduct surface treatment on the implants and change their surface morphology and properties.Papers of the implant by abrasive water jet surface treatment,through erosion method of combining the numerical simulation and experiment,in view of the titanium alloy dental restorations implant surface treatment of base stations,analysis of nozzle diameter,jet standoff distance,jet pressure,abrasive concentration and abrasive diameter,and the effects of processing parameters on the implant surface,specific content is as follows:Based on the basic parameters of abrasive water jet and the material removal mechanism,the characteristics of the initial section.main section and dissipating section of the flow field were described in the aspect of erosion mechanism.The erosion mechanism of single particle and multi-particle on metal was analyzed.The results show that the abrasive water jet can achieve the rough surface without affecting the fitting precision of the implant abutment.A three-dimensional flow field model of abrasive water jet surface treatment was established to simulate the erosion process based on the Discrete Phase Model(DPM).The erosion range and erosion rate characteristics were studied.The results show that with the increase of nozzle diameter and jet target distance,the erosion range increases and the erosion rate decreases.The efflux pressure and abrasive concentration have little effect on the erosion range,and the erosion rate increases with the increase of efflux pressure.The erosion rate increases with the increase of abrasive concentration.With the increase of abrasive diameter,the erosion range increases slightly and the erosion rate decreases.When the target distance is30 mm,the nozzle diameter is 2 mm,the pressure is 0.5 MPa,the abrasive concentration is 25g/L,and the number of abrasive mesh is 150 mesh,it is the best processing parameters to remove the turning marks.When the target distance is 30 mm,the nozzle diameter is 2 mm,the pressure is 0.3 MPa,the abrasive concentration is 10 g/L,and the number of abrasive mesh is500 mesh,it is the best treatment parameters to improve the biocompatibility of surface modification.The abrasive water jet surface treatment test rig was built and the experimental research was carried out.The surface morphology,surface roughness,surface hardness and wetting angle of the sample were measured and compared with the numerical simulation.The results show that the surface treatment parameters and abrasive parameters have important effects on the surface roughness.In order to obtain the ideal surface roughness,it is necessary to optimize the treatment parameters and abrasive parameters reasonably.The average hardness of the metal surface is increased from 30.00 HBC to 35.48 HBC,and the wetting angle is improved.The wetting angle of the metal surface is improved after 1000 mesh treatment76.8°was reduced to 24.1°,and the optimum wetting angle was obtained using 1000 mesh,2000 mesh and 3000 mesh abrasives.The surface treatment experiment of oral implant abutment was further carried out.After the surface treatment,the residual rough machining marks on the abutment were completely eliminated and a loose and rough surface was formed.