SOLIDIFICATION OF UNDERCOOLED MOLTEN SPINODAL

When molten Pd40.5Ni10.5P19 is undercooled way below its liquidus T-l, liquid state spinodal decomposition is observed. Crystallization of t his system is particularly interesting because it has plenty of interf aces. The microstructure of an as-crystallized specimen can be divided into four regions, namely, A: random spinodal; B: aligned and elongat ed spinodal; C: coarsened spinodal and island structure; and D: rod st ructure and ternary eutectics. The origin of these different microstru ctures is discussed.