P. K. Liao

The B-Nd (boron-neodymium) system

Given the scientific and commercial significance of the ternary Nd-Fe-B system, it is surprising that so little is known about the Nd-B binary phase diagram. Figure 1, the assessed Nd-B diagram, was constructed using contributions from a number of sources. The diagram is similar to that for the B-Sm system. Its phases include the liquid, L; the two stable neodymium allotropes, (txNd) and ([3Nd), each with negligible solid solubility ranges; four intermetallic phases assigned the stoichiometries Nd2B 5, NdB4, NdB6, and NdB66; and the terminal solid solution, (~B), with negligible solubility for Nd. The liquidus temperatures and invariant compositions are estimated, largely based on results f0r the B-Sm system [76Spe, 77Spe].