Patent ID: 7586061

Claim:
A method for controlled remelting of a surface of an article, comprising: providing a light source, a signal capturing apparatus, a control system, and a feedback circuit; moving the light source, the signal capturing apparatus and the article relative to each other; melting a portion of the surface of the article using the light source; injecting a powder into the melt pool; forming a melt pool; capturing an optical signal from the melt pool using the signal capturing apparatus; using the optical signal to determine properties including temperature of the melt pool and temperature fluctuations of the melt pool; using the properties from the optical signal within the feedback circuit of the control system to adjust one of light source power and relative speed of the light source to the article such that desired melt pool properties are obtained; adjusting one of the temperature and the temperature fluctuations of the melt pool such that melt pool properties are obtained to avoid Marangoni convection in the melt pool, and solidifying the melt pool.