A short information is given on the results of work carried out at the Branch of the Institute of Chemical Physics, U.S.S.R. Academy of Sciences, since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion.fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds.

A New Class of Combustion Processes

A process for producing ultra-fine ceramic particles with the particle size of less than 1000 A, which comprises the steps of forming powdered dust cloud of metal powder such as Si constituting a portion of aimed ceramic particles in a reaction gas containing the other portion of said aimed ceramic particles, igniting said powdered dust cloud to cause explosive burning and synthesizing said aimed ceramic particles and gathering said resulting ceramic particles. By the process, ceramics particles such as Al 2 O 3 , MgO, SiO 2 , TiO 2 , TiN having particle size of 10 - 100 nm can be produced.

Process for producing ultra-fine ceramic particles

The invention provides a method of making a titanium boride metal matrix alloy, by firing a particulate reaction mixture comprising titanium, matrix material and a source of boron (e.g. boron carbide), under conditions such that the titanium and boron react exothermically to form a dispersion of fine particles (preferably greater than 1 micron and less than 10 microns in size) comprising titanium boride (plus titanium carbide where the source of boron is boron carbide) in a predominantly metal matrix. The titanium and matrix are preferably added as a titanium alloy such as ferrotitanium (e.g. eutectic ferrotitanium) or titanium-aluminium. The reaction conditions are preferably selected so that during the reaction a molten zone moves through the body of the reaction mixture, and the average size of the resulting hard particles is uniform throughout the resulting dispersion.

Metal matrix alloys.

A method for the introduction of in-situ precipitated second phase materials, such as ceramic or intermetallic particles in a metal matrix, to a host metal. When an initial solvent-assisted reaction is utilized, metal-second phase composites having highly superior properties may be obtained. The invention may utilize the reaction of the second phase-forming constituents in a solvent metal medium to provide an intermediate material of finely-dispersed second phase particles in an intermediate metal matrix, in the form of a porous mass or sponge. Any desired loading of second phase in the final composite may be achieved by the admixture of this preformed intermediate material having a relatively high content of particulate material, with a molten host metal. Exemplary materials include titanium diboride in an aluminum matrix and titanium carbide in an aluminum matrix.

Process for forming metal-second phase composites and product thereof

This invention relates to a composite material comprising an in-situ precipitated second phase in an intermetallic matrix, and to the process for making such a composite.

Composites having an intermetallic containing matrix

A METHOD OF PRODUCING REFRACTORY INORGANIC COMPOUNDS SUCH AS CARBIDES, BORIDES, NITRIDES, SILICIDES, OXIDES, PHOSPHIDES, SULPHIDES, FLUORIDES AND CHLORIDES OF METALS OF THE IV, V AND VI GROUPS, IN WHICH AT LEAST ONE OF THE METALS OF THE IV, V AND VI GROUPS OF THE PERIODIC SYSTEM IS MIXED WITH ONE OF THE NON-METALS N, C, B, SI, O2, P, S, F, OR CL2 AND TO THE RESULTING MIXTURE IS INTRODUCED IGNITION MEANS FOR GENERATING A TEMPERATURE SUFFICIENT FOR STARTING THE PROCESS OF COMBUSTION OF THE INITIAL COMPONENTS WHOSE FURTHER INTERACTION TAKES PLACE OWING TO HEAT HENERATED BY THE REACTION, THE REACTION OF METALS WITH METALLOIDS, C, B, SI, P, S BEING CARRIED OUT IN AN INERT GAS MEDIUM.

A Merzhanov

Papers

Method of producing refractory carbides,borides,silicides,sulfides,and nitrides of metals of groups iv,v,and vi of the periodic system