Research Of Curved Layer And Path Planning Method Based On Voxel For Wire Arc Additive Manufacturing

Wire Arc Additive Manufacturing(WAAM)can form large-scale metal parts efficiently and cheaply,and has broad application prospects in aerospace,automobile manufacturing and mold remanufacturing.Because WAAM generally adopts flat layer,it is difficult to form complex curved structural parts,or when forming metal parts with complex surface topography,it is easy to cause local accumulation of energy,uneven temperature field,low processing efficiency,poor surface topography quality,warped deformation and other problems.In view of the above problems,a new voxel-based method is proposed to realize curved layer and curved path planning for WAAM,which improves the surface quality of the parts and reduces the waiting time caused by local overheat in forming process,thus improving the forming efficiency of the parts.Two methods of curved layer based on voxel are proposed.The method of curved layer based on surface offset takes the base surface of part as reference surface,offsets the reference surface equidistantly along the normal direction,intersects with the model of part,and obtains the curved layers.This method can realize curved forming on the base surface of part,significantly reduce the heat-affected zone and weaken the step-effect.The method of curved layer based on growth line draws growth line with stated density through the minimum bounding box of the part and intersects with the surface of the part.According to the thickness of the layer,the intersecting line are divided into several segments.Then determining the number of layers of each division point and obtaining the boundary points of each layer to form the points cloud of curved layers.This method has the advantage of easy realization of variable layer thickness.Two kinds of curved path planning algorithms are developed: zigzag path planning and contour path planning.Zigzag path planning scans forwardly and reversely in Y axis direction or X axis direction to find the starting and ending points of each curved path,and work out the passing points between each starting and ending points.Contour path planning obtains the inner and outer contours of the curved layer,offsets the contours,and forms the contour path.The two path planning methods can be selected according to the technological requirements of different parts.In addition,the subtractive manufacturing path is developed,which is coordinated with the above-mentioned WAAM path to realize the path of additive and subtractive composite manufacturing,so as to improve the precision of WAAM.The above research work has formed a complete set of path planning software for arc curved layered manufacturing.It has been successfully applied in the robot-based WAAM equipment and arc additive and milling subtractive composite manufacturing equipment based on the machining center to produce propeller and steel joint models which are difficult to manufacture in flat layered.