Method for measuring phase boundaries of a material during machining with a machining beam using additional illumination radiation and an automated image processing algorithm, and associated device

US8207471B2 · kind B2 · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Boris Regaard · Gerlingen, DE
• Anas Moalem · Hannover, DE
• Jan Michel · Aachen, DE
• Peter Abels · Alsdorf, DE
• Stefan Kaierle · Herzogenrath, DE
• Wolfgang Schulz · Wunstorf, DE

Key dates

• Filing date: Mar 7, 2006
• Grant date: Jun 26, 2012
• Expiry date: Oct 28, 2028

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B23K26/032
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

The present invention relates to a method for measuring phase boundaries of a material during the machining of a workpiece (12) with a machining beam, more preferably with a laser beam, and a device that is embodied in such a way as to carry out the method. According to said method, during the machining, a machining region (13) containing the impact point of the machining beam (1) on the workpiece (12) is illuminated at least approximately coaxially to the machining beam (1) by means of additional optical radiation (2). Radiation (3) reflected by the machining region (13) is detected, parallel to an incidence direction of the optical radiation (2) or at small angle thereto, by means of an optical detector with local resolution, in order to obtain an optical reflection pattern of the machining region (13). From the optical reflection pattern, a course of at least one liquid/solid phase boundary in the machining region (13) is then determined in an automated manner by means of an image processing algorithm on the basis of a transition from an area containing a large-surface homogeneous area and an area containing a plurality of small-surface homogeneous areas in the optical reflectio…