Product Code: ICA12_607

Analysis of Coaxial Vision Systems for Real-Time Z-Height Control for Laser Cladding Process
Authors:
Rezak Mezari, STAMP - Arts et Métiers ParisTech; Paris France
Pascal Aubry, STAMP - Arts et Métiers ParisTech; Paris France
Thierry Malot, STAMP - Arts et Métiers ParisTech; Paris France
Kevin Verdier, STAMP - Arts et Métiers ParisTech; Paris France
Presented at ICALEO 2012

In order to generate 3D complex structures by laser metal deposition, especially for Direct Manufacturing of parts where the number of deposited layers can be high, it is necessary to control the width and the height of the deposited material. First, we present a general overview of the problem. The Direct Metal Deposition process by YAG laser is presented. Then, the phenomenological model linking the main process parameters with the output parameters (width and height of the deposited material) is described. In the article, we propose to study the possibility to measure the height of deposited material by a coaxial device. The measures of the output parameters (width and height of the melt pool) are made by the dedicated coaxial sensor based on CMOS cameras that we present in the next section. Different optical principles and setup such as defocusing, stigmometer or phase contrast are reviewed and analyzed. Some image processing algorithms are evaluated in order to automatically compute the height of the melt pool. Finally, an overview of the process control system is presented.