Patent ID: 6998568

Claim:
A method for fabricating, modifying or repairing of single crystal or directionally solidified articles, the method comprising the steps of (a) joining of two single crystal or directionally solidified prefabricated parts with matched crystallographic orientation by isothermally brazing using a brazing material, (b) applying a layer on the surface of the article and of the braze joint using a laser metal forming process, thereby (c) moving a light source and a signal capturing apparatus and the article relative to each other, thereby (d) melting locally the surface of the article or of the braze joint using the light source with a specific power for forming a melt pool, (e) injecting powder with a carrier gas or a wire into the melt pool, (f) capturing an optical signal from the melt pool using the signal capturing apparatus, (g) using the monitored optical signal for the determination of temperature and temperature fluctuations as properties of the melt pool, (h) using the information of the temperature and temperature fluctuations of the melt pool from the optical signal within a control system in a feedback circuit to adjust as process parameters one or a combination of the power of the light source, the relative speed between the light source and the article, the mass feed rate of the added material and/or of the carrier gas such that desired melt pool properties are obtained and subsequently (i) solidifying the melt pool.