Study Of Warping Deformation And Stress For Multilayer Of PA6 Powder In Selective Laser Sintering

Selective Laser Sintering is a rapid prototype process that creates 3D objects by the sintering of powdered materials laser beams.SLS technology has attracted much attention in engineering because it don’t need auxiliary support in forming process and produce products with a wide range of materials (plastic, metal and ceramic, etc).In this paper, numerical simulation of temperature field occurring in the process of selective laser sintering is done. This paper comprehensively analyses the relationship between powder properties, fabrication parameters and the temperature field of SLS parts. and find out that the different scanning mode has a great influence on temperature field. the nonuniformity of the temperature field is reduced through the partition scanning method by dividing the whole region into a few pieces of the same local area. Based on the analysis of temperature field under the three scanning sequence (continuous scan, helical scan, intermittent scan) of 9 partition scan, the researchers found that the temperature gradient under the spiral scan order of the temperature field is relatively small,provides a theoretical basis for the optimization of powder sintering experiments.Secondly, the characteristics of the modified method commonly of polymeric materials is introduced. According to the characteristics of the nylon material, this paper select wollastonite powder as modifier and obtain nalyon 6 blends specimens through the surface process of wollastonite powder.Finally,with the guide of finite element analysis, the experiment uses nalyon 6 blends powder to investigate the effect of laser scanning strategy and cascading method on warping and distortion. the results show that the square sintered sample can significantly reduce deformation through the nine subarea adaptive control scanning, and the different scanning sequence shows similar values for the deformation of the sample.the comparative experiments of 15um and 30um of wollastonite powder nylon material show that the smaller the particle size, the better the modification effect, the smaller the optimal filling ratio.