Non-destructive testing equipment and method for directed energy deposition process based on coherent imaging

Abstract

The invention belongs to the technical field related to metal additive manufacturing, and discloses a nondestructive testing device and method for a directional energy deposition process based on coherent imaging. The device includes a first beam splitter, a laser generator, a second beam splitter, and a third beam splitter , interferometer and host computer system, the laser generator is connected to the second beam splitter, the third beam splitter is connected to the first beam splitter and the second beam splitter respectively, and the first beam splitter and the third beam splitter are respectively connected to the interference The interferometer is connected to the host computer system. The upper computer system is used to process the received first interferogram and second interferogram to obtain the molten pool depth variation curve, molten pool height variation curve and molten pool width variation curve, and then the internal pore defects and surface defects of the parts to be inspected Real-time detection is carried out, thereby realizing in-situ online non-destructive detection of internal pore defects and surface defects during the directed energy deposition process. The invention realizes real-time detection and has better flexibility.

Description

technical field [0001] The invention belongs to the technical field related to metal additive manufacturing, and more specifically relates to a nondestructive testing device and method for a directed energy deposition process based on coherent imaging. Background technique [0002] The metal additive manufacturing process is a multi-physics coupling process. There are various unstable factors in the forming process, the temperature changes drastically, the solidification rate of the molten pool is large, and the formed parts are prone to macroscopic defects such as weld bead offset, hump, and flow. Defects, unpredictable metallurgical defects such as cracks, pores, and slag inclusions are prone to appear inside the parts. Small defects such as pores gradually expand under the long-term action of alternating stress, which may eventually cause fatigue fracture accidents, especially in the field of aerospace, once fatigue fracture accidents of important components occur, it wil...

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Problems solved by technology

On the one hand, due to the complexity of the part structure, there will be detection blind spots in the overall inspection, such as radiopaque caused by overlapping structures, skin effect and edge effect of eddy current, etc., which cause parts to be missed; on the other hand, once the inspection finds that there are defects inside the workpiece , the existing repair welding, milling and other methods cannot repair internal defects. Therefore, strengthening quality control, detecting and processing defects in real time, and avoiding waste products in completion inspection are urgent problems that need to be solved in current arc deposition additive manufacturing.

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