On-line detection method of contour accuracy of molding layer in laser selective melting process

Abstract

The invention belongs to the technical field of additive manufacturing on-line measurement, and discloses an on-line detection method of the contour accuracy of a molding layer in the laser selectivemelting process. The on-line detection method includes the following steps that S1, a model of a to-be-machined part is sliced, and an auxiliary image is generated; S2, powder spreading is conduced, and then powder is melted and molded in a laser selective mode; S3, an image of a basic molding area is collected, and a contour of a segmented image is extracted; S4, the image contour is subjected tothree-dimensional reconstruction to obtain an image actual contour; S5, the image actual contour Cr is compared with a contour of a corresponding slicing layer to analyze the accuracy, if the requirements are met, the step S6 is executed, and otherwise, machining is completed; and S6, whether machining of the to-be-machined part is completed or not is detected. According to the on-line detectionmethod of the contour accuracy of the molding layer in the laser selective melting process, the range of image contour extraction can be effectively and accurately delimited, and then the number of iteration times in the calculation process is greatly decreased; and thus the extraction accuracy of the image contour reaches the sub-pixel level, and accurate and rapid contour detection is realized.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing, and more specifically relates to an online detection method for contour accuracy of a forming layer during laser selective melting. Background technique [0002] Additive manufacturing technology has matured rapidly in recent years due to the development of additive manufacturing technology and materials, as well as the in-depth understanding of basic design concepts. Additive Manufacturing Powder Bed Fusion Processes (AM PBF) is one of the seven additive manufacturing technologies defined by the American Society for Testing Materials (ASTM), which mainly includes laser selective melting (SLM) , Direct Metal Laser Sintering (DMSL), Selective Laser Sintering (SLS) and Electron Beam Melting (EBM). At present, this technology is widely used in aerospace, mold manufacturing and other fields. However, the lack of quality inspection of additive manufacturing parts hinders the promotion...

AI Technical Summary

Problems solved by technology

However, these methods directly extract the contours of the collected images, which are easily disturbed by the working environment and noise, and cannot achieve accurate and fast contour detection.

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