Abstract: Powdered mixtures of transition IV-VI group metals with boron were milled in a planetary mill at a drum rotational speed of 1840 rev/min in an argon atmosphere. The balls-to-powder mass ratio was 20:1. XRD data and modeling for formation of boron-in-metal solid solutions showed that refractory borides of transition IV-V group metals are formed under mechanical alloying by two mechanisms: 1. Mechanically induced self-propagating reaction, determined by the enthalpy of refractory compound formation and the capability to form a substitutional solid solution. 2. Formation of interstitial boron-in-metal solid solutions, their subsequent decomposition and the appearance of the MeB2 phase.
Author: M. Savyak
Keywords: Borides, Mechanosynthesis, Solution