Critical assessment of the enthalpy of fusion of metals used as enthalpy standards at moderate to high temperatures

Enthalpy of fusion values for metals used as enthalpy standards are critica lly assessed. Recent developments of high temperature DSCs imply that poten tial standards for higher temperature use must also be considered. The fusi on values for Ga, in, Sn, Cd, Bi, Pb, Zn, Sb, Al, AE, Au, Cu, Ni and Co are treated here. We are hence covering materials for use from ambient tempera ture and up to 1768 K. A detailed review of the enthalpy of fusion determin ations reported for each individual metal is presented in terms of sample q uality and the methodology used. The accompanying evaluation leads to recom mended values for the enthalpy of fusion of the metals and estimates of the uncertainty of the mean. The statistical method used is discussed in some detail. In reaching the recommended values for the enthalpy of fusion of th e metals, the uncertainty of each individual determination has been estimat ed. Arguments regarding the effects of sample quality, intrinsic defects, a nd thermal treatment to aid in the assignment of uncertainties as well as a short review of the main calorimetric techniques used are presented. (C) 1 999 Elsevier Science B.V. All rights reserved.