Partial and integral enthalpies of mixing of liquid ternary Bi-Cu-Sn alloys at 800 degrees C were determined along nine sections in a large composition range. Additionally, binary alloys of the constituent binary system Bi-Cu were investigated at 800 and 1000 degrees C. Measurements were carried out using a Calvet-type microcalorimeter and a drop calorimetric technique. The binary data were evaluated by means of a standard Redlich-Kister polynomial fit whereas ternary data were fitted on the basis of an extended Redlich-Kister-Muggianu model for substitutional solutions. (C) 2008 Elsevier B.V. All rights reserved.