Abstract: In the selective laser sintering process,the powdering efficiency and the powder density will directly affect the forming efficiency and molding quality of the molded parts.In order to improve the quality of powder,the powder device was analyzed and compared,and a new powder distribution scheme was put forward.Firstly,the structure of the powdering device is improved,and the kinetic analysis of the modified powder coating device is carried out.the force model of the powder particles under the action of powder was established.Then,based on the theoretical analysis of the model,the main parameters affecting the quality of the powder are the radius,roughness,rotation direction of the laying powder and the translation speed of the scraper and the laying roll.Finally the laser sintering equipment after the improvement of the powder coating device is used to study the experiment design.The results show that the improved powder coating device has a better effect on the molding quality of the molded parts,and it is concluded that with the increase of the roll speed,the dimensional accuracy of the molded piece will increase first and then decrease.

Key words: laser sintering, powder quality, kinematics analysis, spread powder device, powder roll speed