Research And Implementation Of Online Detection For Additive Manufacturing Process Based On Arc-based Deposition

Additive manufacturing of arc-based deposition is a new technology, which manufactures metal parts fast and free with arc welding and additive manufacturing. This technology will be used widely in the field of metal additive manufacturing for its advantages in efficiency, cost, density, non-mold and abundant materials. Howeve,arc welding process lead to lower precision, poorer quality, residual stress, welding distortion and welding defects, such as cracks, gas pockets, slag inclusion. Therefore, at present, it is urgent to strengthen quality control, detect defect and avoid waste to additive manufacturing of arc-based deposition. Focusing on the particularity of additive manufacturing, this paper proposed a solution based on hierarchical detection, which introduced an appropriate online detection method for additive manufacturing process.Hierarchical detection in this paper is based on discretization principle of additive manufacturing. It changes the overall detection in traditional process to the scattered detection which take the phased processing unit as detecting object in manufacturing process. This study, which based on the additive manufacturing project of high-speed rail frog in research group, researched the characteristics of the actual process, combed the requirements of the detection and the design index of detection system. And chose permanent magnetic perturbation detection as the optimal method of online detection for additive manufacturing of arc-based deposition process by multi-index comprehensive evaluation, based on full research on ultrasonic testing(UT), radiographic testing(RT), eddy current testing(ET), infrared testing(IT), metal magnetic memory testing(MMMT), magnetic flux leakage testing(MFL) and permanent magnetic perturbation testing(PMP). Permanent magnetic perturbation testing takes advantage of magnetic perturbation effect to capture the magnetic perturbation which is produced by defects on the area, and obtain the judgment of defect. Permanent magnetic perturbation online detection System is designed combine to the actual situation of additive manufacturing process. The detection system test on a series of samples, which is placed in the actual processing environment, and obtain large amounts of experimental data. By analyzing and sorting data, the testing verify that an open crack defects with 0.3 mm in width, a internal hole defects with 0.3 mm in diameter and a diameter of 1.0 mm internal defects with 3 mm in depth,can be detected successful. The detectability of system reached the requirements of design index.Permanent magnetic perturbation detection system realize online detection for the process of additive manufacturing of arc-based deposition by hierarchical detection. Detection system match with manufacturing system, and make it integrate, automate and intelligent. The introduction of the detection system, greatly strengthen the quality control, avoid waste, reduce the production cost.