Additive manufacturing on-line detection and repairing method

Abstract

The invention discloses an additive manufacturing on-line detection and repairing method for detecting and repairing defects of layers in the additive manufacturing process. A detection system comprises a detection module and a data processing module, a linear guide track is adopted to achieve automatic positioning and axial movement of a camera, layer images are acquired by using a double-CCD (Charge-Coupled Device) camera, in addition, defect characteristics are extracted by using an edge algorithm, then quantification and positioning of defects can be achieved, and the defects are subjectedto selective laser remelting. The method has the technical effects that an on-line detection and closed loop control method applicable to defect quantification, positioning and repairing in the additive manufacturing process, and the product quality of additive manufacturing can be ensured.

Description

technical field [0001] The invention belongs to the field of non-destructive testing, and relates to an online detection and repair method for additive manufacturing, in particular to a method of using machine vision technology to realize quantification and positioning of sheet defects in the process of additive manufacturing and using a laser remelting process to eliminate specified defects closed-loop control method. Background technique [0002] 1. Additive manufacturing technology is an advanced intelligent digital manufacturing technology developed in the late 1980s. It is based on product model data and accumulates materials layer by layer to form a physical manufacturing method. Its core is layering-superposition, which converts the manufacture of three-dimensional parts into a series of two-dimensional sheet layers, uses computer modeling to discretize the model, and then superimposes and solidifies it in the processing system. Due to the characteristics of rapid pr...

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Problems solved by technology

[0003] 2. However, additive manufacturing is the accumulation and formation of powder by high-energy beam melting, and at the same time lacks the traditional forging process. In the manufacturing process of additive manufacturing products, defects such as pores and cracks will inevitably appear, and these defects directly affect additive manufacturing components. Mechanical properties and service life

Traditional testing methods such as ray testing, ultrasonic testing, eddy current testing, etc. are mostly off-line testing, that is, relevant parameter testing is performed after manufacturing, so it is impossible to solve the defects that occur during the additive manufacturing process

In order to ensure the quality of the product, it is necessary to carry out online detection and repair the defects in time. The patent document with the application publication number CN106018288A and the publication date is October 12, 2016 proposes a method for online detection of additively manufactured parts by laser ultrasound. The amplitude change of the excited surface wave detects metallurgical defects produced in the additive manufacturing process, but the laser detection steps are cumbersome, and the scanning time at the slice level is too long, which directly affects the work efficiency; such as the application publication number CN106881462A, the publication date is June 23, 2017 The Japanese patent document discloses an online detection method using a single CCD camera. In the method, a CCD camera is used to scan for layer defects, and the information is fed back for process optimization. However, due to the lack of timely repair of defects in this method, product defects Still exist

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