X-Ray Investigations of the Ternary System Fe-P-B. Some Features of the Systems Cr-P-B, Mn-P-B, Co-P-B and Ni-P-B.

Abstract

Abstract : The solid region of the Fe-P-B system was investigated in the range Fe-FeP2-BP-FeB-Fe by means of x-ray and chemical analyses. The main features of an isothermal section at 1000 C have been determined. Boron substitutes for P to a large extent in Fe3P and to a smaller extent in Fe2P and FeP. Two ternary phases exist, Fe5PB2 and Fe3P sub 1-x B sub x, where the phase is homogenous when x ranges between 0.48 and 1. Solid solubility of B is appreciable in Cr3P and Mn3P, but is very restricted in Ni3P. The ternary phase Mn5PB2 is isostructural with Fe5PB2. In the Co-P-B system, 3 ternary phases have been found, Co3P sub 1-x B sub x, Co3P sub 1-y B sub y, and Co5PB2. The crystal structures of Fe3P0.37B0.63 and Fe5PB2 were determined and refined using single-crystal methods. (Author)