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

Abstract

The invention belongs to the technical field of on-line measurement of additive manufacturing, and discloses an on-line detection method for contour precision of a forming layer in a laser selective melting process. The on-line detection method includes the following steps: S1 slices the model of the part to be processed, and generates an auxiliary image; S2 spreads powder, and then selectively melts the powder into shape by laser; S3 collects the image of the substantially formed area, and The segmented image is subjected to contour extraction; S4 image contour is carried out three-dimensional reconstruction to obtain the actual contour of the image; S5 compares the actual contour Cr of the image with the contour of the corresponding slice layer, and analyzes the accuracy. If the requirements are met, then enter step S6, otherwise, end this chapter secondary processing; S6 detects whether the processing of the part to be processed is completed. The method of the invention can effectively and accurately define the range of image contour extraction, and further greatly reduce the number of iterations in the calculation process, so that the extraction accuracy of the image contour can reach the sub-pixel level, and realize accurate and fast contour detection.

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.

Images