Research On The Key Technic For Rapid Prototyping & Manufacturing

Rapid Prototyping is a kind of complex technology which combines CAD, laser, precision machine, CNC with new materials, which belongs to the frontier field of advanced manufacturing technology. In the rapid prototyping production technics, some issues are immanent such as deformation, warping, collapsing and so on which lead to failure. Even if the parts have been manufactured successfully, it will have the big influences on the quality of shaped parts. The research of the rapid prototyping production technics is carried out which plays an important role in solving the above issues and improve the research level of rapid prototyping. In order to solve the above issues, this paper is mainly focused on research of the three key parts including scanning system data processing, scanning strategy and support technics. The main research contents and results are as follows:In rapid prototyping scanning system data processing, two-dimensional scanner geometry correction fast algorithm is proposed, and do the research on deferred processing of laser scanning and so on, meanwhile, scanning system is optimized and completed by optimizing velocity and acceleration in scanning process, optimizing connected transition between scanning stroke and idle stroke, and using pipeline organization in scanning system.On the research of scanning strategy, concerning the problem of producing stress concentration in processing complex parts by progressive scan or changing directon scanning strategy which causes the deformation warping, the helix scanning strategy on the basis of Voronoi diagram is used to reduce the stress in scanning vector direction and vertical scanning vector direction, lower the trend of deformation warping, and then be applied in SLM, meanwhile, solve the crucial issues such as the warping deformation which are easily produced in processing complex parts by progressive scan or changing direction scanning strategy, and produce the complex aviation parts and components. Concerning SLM of the round parts with cavity inside, complex ring algorithm scanning strategy is proposed to preheat and scan when every layer has melted and formed, and solve the warping deformation on processing round parts by progressive scan or changing direction scanning strategy.In the research of support technic, it puts forward many types of support generation algorithm, has analyzed the application characteristics of various types of support, and puts forward rapid recursion area gleaned algorithm through constructing the topology relation among the triangles and edges in STL model, and applies to the generation algorithm of region support. For STL model in complex shape, the generation algorithm of suspension support is presented. Through the analysis of suspension points and geometrical characteristics of the overhang lines, it puts forward a method which can automatically extract the overhang points needing support, support-waiting plane of the overhang lines and the to-support position, consequently, aiming at the complex situation of intersection calculation between support line and STL model when the generation of the regional support, the traditional algorithm is optimized and then the algorithm improve efficiency greatly, finally it is tested in practice.In selective laser melting (SLM) production technic research, based on the analysis of some existing serious problems, especially on the analysis of easily warping deformation problem in the process of processing complex components in SLM, a series of new production sub technic and the technic optimization have been put forward: according to deformation cumulative effects, it puts forward changing the layer thickness of technic dynamically in the process of production; according to the problem of adding support at the bottom of the parts in SLM technic as needed in SLA technic, has studied the application mode and algorithm of body support; according to different production directions in SLM technic, especially on the laid problem in Z direction and horizontal direction, has been studied by the experiment in forming direction, and puts forward keeping large area at the bottom in Z direction and small area on the top which can form into position pyramid direction, and in the level location should make the long side of the parts and the movement direction of powder roller parallelize; according to some layers arising melting and warping deformation in powder bed directly when the complex components have cavity in Z direction, the author puts forward a new kind of backward deformation support production structure to suppress this deformation; finally also has some simple research on annealing technology of reducing the internal stress of the parts.By analyzing mechanism of production of the above issues, optimization process on the scanning data, optimization support technics and two new type scanning strategy are use to solve the above issues which can reduce the deformation of the parts, warping and collapsing. On the basis of the research on selective laser melting (SLM) production technics, some sub-technics are proposed to reduce the warping deformation in SLM, and improve the research level of SLM.Through above-mentioned the experiment of processing sub technic and application, it indicates that it will not cause failure because of warping deformation in the process of making complex components, which can ensure smooth production and improve the surface precision of the parts after production.