Using Wollastonite as a Metal lorn atrix Composite Materials Filler and Alloys Structure Modifier

摘要

Calculations data of the Gibbs energy of interaction reactions between wollastonite, light metals and basic alloying elements of aluminium and magnesium alloys are presented in the paper. Based on this, prediction of the most probable reactions was made. Interaction of magnesium and aluminium melts with wollastonite surface was investigated by the method of diffusion pairs. It was shown that reaction diffusion is evolving in that case. Aluminium reacts with wollastonite at the temperatures above 800 °C, therewith calcium and silicon are recovering to the elemental state and formation of Al_2O_3, Ca_2Al(Al,Si)_2O_7, Ca_3Al_2O_6, CaAl_4O_7, CaAl_2Si_2 compounds takes place. Magnesium intensively interacts with wollastonite at the temperatures above the melting point which leads to obtaining MgO, CaMgSi, Ca_2SiO_4 compounds. Assumptions about mechanism of light-metals base alloys structure modification by wollastonite were made. Possibility to use a needle-shaped wollastonite as a filler of alumomatrix composites was shown.