A defects detection method based on infrared scanning in laser metal deposition process
ISSN: 1355-2546
Article publication date: 18 July 2018
Issue publication date: 15 October 2018
Abstract
Purpose
Laser metal deposition (LMD) is an important additive manufacturing (AM) technology, but the metallurgical defects, such as cracks and porosities, produced in LMD process will seriously affect the mechanical properties of the parts. The purpose of this paper is to propose a novel in-process defects detection method based on infrared scanning for LMD.
Design/methodology/approach
The defects detection principle is that, after every three to five layers have been deposited, the optical head of a high-precision infrared two-color pyrometer is driven to scan the defects by measuring the abnormal temperature peaks on the deposited surface. The experiments for verifying the defects detection principle were carried out.
Findings
The relationship between the temperature peak value and the dimensions of the defect was analyzed based on the heat conduction theory and curves of temperature peak value versus crack width or diameter of porosity.
Originality/value
This method can effectively improve the detection accuracy and the defects can be precisely located, which can meet the requirement of laser targeting re-melting and elimination of the defects.
Keywords
Acknowledgements
The work is supported by the grant of National Natural Science Foundation of China (No. 51775430) and Science & Technology Coordinate Innovation Program of Shaanxi Province, China (No. 2015KTTSGY03-05).
Citation
Xie, R., Li, D., Cui, B., Zhang, L. and Gao, F. (2018), "A defects detection method based on infrared scanning in laser metal deposition process", Rapid Prototyping Journal, Vol. 24 No. 6, pp. 945-954. https://doi.org/10.1108/RPJ-04-2017-0053
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited