Soldadura fuerte (Brazing) al vacío de radiadores de aluminio Guía de solución de problemas y perfil térmico

This article provides a comprehensive troubleshooting guide for vacuum brazing processes of aluminum radiators, focusing on components manufactured with 6000-series alloys, without the use of flux and employing clad sheets as the filler metal source. Six primary causes of joint defects are identified: insufficient vacuum, surface contamination, inadequate thermal parameters, uneven heating, excessive joint gaps, and improper material selection. Each cause is analyzed in terms of diagnostics, corrective actions, and preventive measures, supported by specialized literature and industrial best practices. The document also presents a detailed thermal profile for multizone vacuum furnaces, optimized for a typical load of 24 radiators, featuring staged heating ramps, thermal equalization plateaus, and controlled cooling. Critical values are defined, including vacuum level (<10⁻⁵ mbar), surface tension of the molten filler (~880 mN/m), and minimum surface energy of the base aluminum (~500 mN/m), to ensure effective wetting. The proposed methodology aims to standardize the process and enhance the reliability of brazed joints in demanding industrial environments.