Solid Solubility Effect on Properties of Titanium Diboride

Abstract

The effect of solute additions on the lattice constants of (Ti,Me)B 2 alloys is reported. The data are based on the literature and on additional experimental work. Variation of lattice constants, calculated from crystallochemical principles, agrees satisfactorily with measured values for dilute solid solutions. Increased solute concentration causes positive deviation for (Ti,Cr)B 2 , (Ti,Zr)B 2 , and (Ti,Al)B 2 because lattice dilation is affected by both the valence of the solute and the size of the metallic radii. It is postulated that lattice anisotropy and elastic strain energy increase in the solid solutions and that they determine the grain‐boundary cohesion in polycrystalline TiB 2 . Knowledge of the lattice dilation properties of TiB 2 solid solutions indicates how the mechanical behavior of diboride ceramics could be improved.