Study On The Part Precision Of Rapid Prototyping Of Selected Laser Sintering

The SLS technology actuality in our country and abroad is analyzed. Firstly the interactional principle of laser and material, the physical and chemical properties of the thermoplastic plastic is studied in theory, and the laser sintering mechanism of powder is also studied. The influence of process parameter to laser sintering process is discussed. In the view of the process parameter that influences the sintering surface roughness, dimension precision of PS part and the surface roughness and shrinkage being guideline, the 3-factor and 3- horizontal orthodoxy experiment is designed and processed. The best process parameter combination and the influence rule for PS material is got by the application of square error analysis method. The experiment indicates that the laser sintering power, the thickness of sintering layer, the placement angle influence the surface precision greatly, and scanning space influence the dimension precision of the part greatly. Based on the new technology application in new process, this paper makes use of the method of experiment and theory analysis, studies the influence of laser sintering parameter to PS material machining precision, and the rule of the influence of each parameter to sintering part is got through the analysis and study of experiment data and discussion of the formation reason of several disfigurement in sintering part. The measure and method of minimize the sintering disfigurement is presented, which could be a guidance to the optimization of process parameter in the thermoplastic application of laser sintering prototyping.The surface ladder effect produced by prototyping principle is analyzed, and the calculation method of the part surface roughness is presented. The selecting method of slice thickness and sintering layer thickness when slicing the CAD model and sintering is presented. To give attention to the prototyping efficiency and partprecision, the variational thickness slice algorithms is presented based on the distinguishing of triangle plane outer-normal direction. This method controls the surface roughness of prototyping part, which provides theory basis for the development of system of variational thickness control.