Moderately refractory method for assembling parts made from SiC-based materials by non-reactive brazing in an oxidising atmosphere, brazing suspension and seal and assembly obtained by this method.

摘要

#CMT# #/CMT# The process of assembling two parts (1, 2) made of silicon carbide materials by non-reactive brazing in an oxidizing atmosphere, comprises contacting the parts with a non-reactive brazing composition, and heating the assembly in an oxidizing atmosphere formed by the parts and the brazing composition at a brazing temperature sufficient to melt the brazing composition to form a moderately refractory joint. Titanium oxide and boron oxide are added to the brazing composition. The process further comprises forming a brazing composition powder, and placing the powder in an organic binder. #CMT# : #/CMT# The process of assembling two parts (1, 2) made of silicon carbide materials by non-reactive brazing in an oxidizing atmosphere, comprises contacting the parts with a non-reactive brazing composition, and heating the assembly in an oxidizing atmosphere formed by the parts and the brazing composition at a brazing temperature sufficient to melt the brazing composition to form a moderately refractory joint. Titanium oxide and boron oxide are added to the brazing composition. The process further comprises forming a brazing composition powder, placing the powder in an organic binder to obtain a suspension or paste, and coating a surface of the part to be assembled with the obtained suspension or paste and then contacting the surfaces to be assembled of parts so that the suspension or paste are intercalated between the surfaces. The parts to be assembled are contacted by observing a gap between the surfaces to create a surface capable of receiving the suspension or paste near the joint formed by the surface to be assembled and then laying the suspension or paste on the surface. The brazing is carried out at a temperature of 1350-1650[deg] C for 2-30 minutes. The assembly formed by the parts and the brazing composition is brought to the brazing temperature by introducing it directly in a device such as a furnace and observing a rise in temperature from ambient temperature. Independent claims are included for: (1) a refractory brazing composition; (2) a refractory joint; and (3) an assembly comprising two parts made of silicon carbide materials. #CMT#USE : #/CMT# The process is useful for moderately refractory assembling two parts made of silicon carbide materials by non-reactive brazing in an oxidizing atmosphere, and for making a refractory joint (claimed). #CMT#ADVANTAGE : #/CMT# The process is capable of simply, economically, precisely and uniformly refractory assembling of two silicon carbide parts by effective non-reactive brazing in an oxidizing atmosphere thus providing an excellent refractory joint or seal without any defects and/or cracks and with improved mechanical strength. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure shows a schematic view of specimens including shearing, joints and assemblies used for mechanical testing. 1, 2 : Two parts 3 : Shears. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Components: The non-reactive brazing composition is a composition A constituted of 22 mass% of silicon dioxide, 37 mass% of aluminum trioxide and 41 mass% of calcium oxide, or a composition B constituted of 50.5 mass% of aluminum trioxide, 44 mass% of calcium oxide and 5.5 mass% of magnesium oxide. The oxidizing atmosphere contains oxygen such as atmospheric air and oxygenated argon or helium. The materials made of silicon carbide includes 100 mass% of pure silicon carbide (SiC) such as pure alpha (SiCalpha ) or beta (SiCbeta ), composite materials made of SiC such as composites having fibers and/or silicon carbide matrix, SiC sintered without pressure, infiltrated SiC, porous recrystallized SiC, silicon-graphite constituted of graphite and covered by a layer of SiC, SiC composites having whiskers of carbon, and monocrystals of Sic and composites with another ceramic such as silicon nitride, SiC or titanium nitride.