Abstract: The present invention provides: refractory composite materials protected against oxidation at high temperature; said materials are of the type made by a solid process and include, in characteristic manner, over their entire outside surface, a complex layer containing at least one silicate corresponding to a densification additive used to make them, silica, and a vitreous boron-containing silicate phase; precursors or intermediates for preparing said materials; said precursors including, in characteristic manner, over their entire outside surface, at least one layer of a precursor for borosilicate glass or a layer of borosilicate glass; and a method of preparing said materials (by preparing said precursors) and a method of preparing said precursors.

Abstract: A device for measuring the deformation of a mechanical test specimen, and including a pressing member (3) for stressing a substantially flat specimen (16) in controlled manner by means of a punch (25); a Michelson interferometer having an optical branch (9d) defined optically by a first face (16b) of the specimen (16), and for generating interference images related to the deformation of the specimen (16); a telecamera (44) for acquiring and digitizing the interference images; and a processor (27) for processing the digitized images and controlling the measuring process fully automatically. The interferometer (9) may alternatively perform white light interferometry measurements, ESPI measurements, or ESPI profilometry measurements, by simply substituting the light source and control software.