Soldering terminology

Brazing method for aluminum developed by the Canadian company Alcan. In this method, eutectic alloys of potassium fluoroaluminates K ₃ AlF ₆ to KAlF ₄ are used as flux, the behavior of which corresponds to the phase diagram of the binary system AlF ₃ - KF (44% AIF ₃, 56% KF, eutectic temperature: 562 °C). The soldering process takes place under inert N ₂ gas or in an atmosphere with a low dew point. In its molten state, the flux is highly active, whereas it is completely inactive at room temperature. Purification after brazing becomes superfluous. It is easy to recall the name Nocolok because it refers to the unchanged color (" no color") after soldering.