Decomposition Activation of Hydroxyapatite in Contact with β-Tricalcium Phosphate

Abstract

The paper examines the interphase interaction in mechanical mixtures of thermostable hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) powders depending on the annealing temperature, initial composition, and particle size with x-ray interpretation of phase changes. It is established that HA transforms into β-TCP by dehydration reaction during annealing of the mechanical mixtures of HA and β-TCP powders. The dehydration reaction is activated through the mechanical of interphase activation in which the limited stage of nucleation disappears. The interphase boundaries in the biphase HA-TCP mixture are more permeable for water vapors than monophase boundaries owing to their disordered structure.