Phase diagram sample preparation

The procedures by which samples are prepared for phase diagram studies are examined and critically evaluated. The three key elements that require attention (alloy purity, homogeneity, and equilibrium) are separately addressed, and several examples of bad procedure are presented with information on their past and future consequences. The origin of commonly confronted problems are described and special procedures are suggested for their circumvention. Additionally, new methods for the early detection of some sample problems are presented, and the usefulness of rapidly solidified materials (as specimens) in phase diagram studies is illustrated.