Process Planing And Experimental Research On Automatic Wire Arc Additive Remanufacturing For Hot Forging Die

To solve the problems encountered in remanufacturing hot forging die when using artificial surfacing technology like dimensional control difficulty,big machining allowance(waste of welding materials),poor working conditions,unstable structure properties and so on,automatic wire arc additive remanufacturing(WAAM)technology is put forward to replace artificial surfacing.By using disabled forging die as remanufacturing substrate,this new method can bring out double advantages of low cost and high accuracy,which is of great application prospect.Because WAAM started rather late in our country,its forming accuracy and automation level have a large gap with international advanced level.Therefore,the core processes like parameters optimization for wire arc additive remanufacturing,the slicing algorithm for complex components,the route planning method for fill path and so on are eagerly to be solved.In this paper,the WAAM process of a disabled crankshaft forging die is studied,which includes researches on the mapping relation of welding parameters and weld shape,the weld shape prediction and welding parameters optimization,the slicing algorithm and route planning and so on are conducted.After then,the WAAM experiment on crankshaft forging die is carried out.The main research contents are as following:(1)To analyze the effects of welding parameters and weld shape on forming efficiency and quality,plate WAAM tests are conducted and results under various welding parameters of weld profile are statistically processed.The parameters range is confirmed.Based on the test results mentioned above,the BP neural network with good predictability and generalization ability are trained,which is used for database expansion.(2)To solve the problem of getting optimal welding parameters corresponding to the target weld shape,the parameters optimization modal is developed based on the trained BP neural network and modified hill climbing algorithm.Then,the parameter optimization software is wrote and tested on MATLAB.The results show that this software is reliable enough to satisfy the demands of weld shape prediction and welding parameters optimization.(3)The Point,Triangle and STLModel are designed to save data based on the structural features of STL modal.The drawbacks of traditional slicing algorithms are analyzed,based on which a new one is proposed.The new slicing algorithm gets its outline polygon by finding the intersection points firstly and then reconstructing these points as a cycle,whose treatment efficiency and practicability are much higher.Then,the interpolation fitting algorithm is introduced to improve the accuracy of outline polygon and the criterion equation of outline polygon’s antegrade or retrograde is deduced.Finally,the calculation method of discrete polygon is developed.(4)By analyzing the merits and demerits of conventional filling algorithm,a composite filling algorithm with uniform inside and smooth margin is proposed.The conversion interface and transfer approach between filling path and robot instruction are developed.Through overall consideration of WAAM system,hardware structure of digital welding inverter and welding process,the business logic classes of WAAM route planning software is developed and the software is designed by separating business logic and UI logic.(5)The common modes,location and reasons of crankshaft forging die’s failures is analyzed based on the production status in factory.Then the technological process of crankshaft forging die’s wire arc additive remanufacturing is introduced and conducted,which justified the feasibility of the whole process.