Process planning of automatic wire arc additive remanufacturing for hot forging die

Many problems like precision control difficulty, unstable structure properties, and waste of welding materials were encountered when remanufacturing hot forging die with manual arc surfacing method. Therefore, the automatic wire arc additive remanufacturing (WAAM) technology is put forward. By using failed forging die as remanufacturing substrate, this technology can bring out double advantages of cyclic utilization and high accuracy, which is of great application prospect. In this paper, the WAAM process of a failed crankshaft forging die is studied. Firstly, a new slicing algorithm which gets its outline polygon by classifying and reconstructing the intersection points of triangular patches and tangent planes is proposed. The key thought of this algorithm is to judge the order of these intersection points with normal vector and put them into the “starting” or “ending” arrays. By traversing through these two arrays, the treatment efficiency gets much better than before. Simultaneously, by parameterizing the chord length accumulation, an interpolation fitting algorithm is introduced to improve the accuracy of outline polygon and the criterion equation of outline polygon’s orientation is deduced. Then a composite filling algorithm with uniform inside and smooth margin is developed to meet the requirements of WAAM process. Finally, the WAAM process for a failed crankshaft forging die is conducted, which justifies the feasibility of the whole process.