MATERIAL HAVING MULTILAYER STRUCTURE AND INTENDED FOR CONTACT WITH LIQUID SILICON Russian patent published in 2013 - IPC C04B35/573 C04B41/87 B32B18/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to novel materials having a multilayer structure, intended for contact with liquid silicon in melting and hardening processes thereof, particularly growing silicon crystals for use in photovoltaic applications. An element of the material includes a first (supporting) layer with open porosity of 25-40%, consisting of graphite granules with size of 1-10 mcm; a surface layer formed from silicon carbide, and an intermediate layer formed by a silicon carbide matrix containing at least one carbon inclusion. Volume content of silicon carbide in that layer is equal to 45-70%, which corresponds to volume content of the original porosity of graphite which forms the supporting layer, multiplied by at least 1.2. The method involves preparing an element of the material, having an outer layer of graphite granules with size of 1-10 mcm, with thickness of at least 1000 mcm and porosity of 25-40 vol. %; bringing the element into contact with liquid silicon, holding for 10 minutes to 1 hour at temperature of 1410-1500°C, bringing the element to temperature of 1500-1700°C and holding for 1 to 8 hours in order to form a surface layer and an intermediate layer.

EFFECT: longer service life of materials in contact with molten silicon, preventing adhesion of silicon to the material.

9 cl, 1 ex, 5 dwg