Estimation of Eutectic Structure in Al-Si alloy by “Sodium Equivalent”

Abstract

  The parameter “sodium equivalent” which controls eutectic silicon structure was proposed. The drawbacks of conventional evaluation technology were clarified by comparing the eutectic silicon structure and shrinkage characteristics of different alloy ingots. The principle of measuring the “sodium equivalent” was described. The characteristics were shown by an evaluation of similar alloy ingots. An example of usage was also introduced.