Study On Forming Quality Of Selective Laser Melting Ti6Al4V Titanium Alloy Based On Partition Scanning Strategy

The selective laser melting process has been widely used for manufacturing medical instruments such as department of orthopedics implantation,dental dental repair and auxiliary medical equipment because of its outstanding characteristics,such as individualized manufacturing,easy forming complex structure,high precision and excellent mechanical properties of forming parts.In spite of this,the problems of poor surface quality of forming parts,poor overhang structure,easy surface adhesive powder and insufficient forming ability of special geometry often impede the popularization of SLM technology.In order to solve these problems,This dissertations adopts the YLM-300-III selective laser melting equipment developed by JIANGSU YONGNIAN Laser Forming Technology Co.,Ltd.Based on the partition scanning strategy,the influence of the main parameters of the partition scanning on the surface quality,the density and the microhardness of the Ti6Al4 V titanium alloy SLM forming parts was studied,and the optimized forming process parameters were obtained.Collocation parameters,such as contour scanning parameters,were also studied,and optimized collocation parameters were obtained.The forming ability test of optimized process parameters was carried out by using the formability test model.Used the orthogonal and single factor experiments,the surface quality,the density and the microhardness of the sample that formed under the condition of the partition scanning strategy and the traditional overall scanning strategy were analyzed.First,four typical surface morphologies of medical Ti6Al4 V titanium alloy were summarized.Considering the test results of surface quality,density and internal microstructure,the optimized main parameters of partition scanning were obtained.Based on the scanning strategy of multiple border with inner filling,orthogonal experiment was used to optimize the contour scanning parameters.According to the side sticky condition of experimental results,it was divided into 4 grades of sticky powder,and a better contour scanning parameter process parameter was concluded.With the help of Solid Works software,the test chart of part forming ability was designed,and the.stl format file of the model was processed by professional software.The forming ability of the process parameters was tested by this modelsystem.The test results were good.The influence of the parameters of the partition scanning,the contour scanning parameters,the inclination angle of the forming surface,the single layer scanning mode,the compensation value of the spot,the scaling coefficient of the model and the rotation angle between the layers on the forming quality of the Ti6Al4 V titanium alloy in the selective laser melting process were studied,and the value of the corresponding factors after the optimization was obtained.The process of selective laser melting forming Ti6Al4 V titanium alloy denture bracket was introduced.The requirements of the design of the denture bracket model were analyzed,and the hierarchical processing of the general model was obtained.In addition,the requirements for forming process were summarized,and the post-processing procedure of titanium alloy denture bracket after forming was explained.Titanium alloy denture bracket which can be used for clinical treatment was obtained.