Application of an Electrochemical Sensor to Measure Sodium Levels in Aluminum Alloys M. Stackpool Ionotec, USA J. Drekeyser Vito, Flemish Institution for Technological Research, USA A. Moores Foseco Foundry Int'l, USA S. Devolder Verheart Design and Development, USA Sodium (Na) has been used for many years to modify aluminum silicon alloys, but one of the problems associated with its use is that after addition, the Na content declines rapidly due to evaporation. As a result, it is difficult to control Na content within defined limits, which is necessary for good casting properties. Currently spectrometers are used to measure the sodium content, however, there is usually some delays between sampling and the test result, and the whole process can be time consuming and costly. An electrochemical Na sensor has now been developed which is capable of giving an immediate and real-time read in exactly the same way that thermocouples are commonly used to monitor metal temperatures. This gives the foundry the ability to control the Na levels within much tighter specifications giving much better control of the metal properties of the finished casting. This presentation will discuss the development, science and application of an electrochemical sensor to monitor and control Na modification with real time modification. |