Ceramics based on oxygen-free Si<sub>3</sub>N<sub>4</sub> and SiC

HIGH-TEMPERATURE THERMOSTRESSED PRODUCTS FROM CERAMIC MATERIALS BASED ON Si₃N₄

Mechanical engineering, nonferrous metallurgy, chemical and glass industry, medical equipment, jewelry industry

Thermocouple sheaths

Monolithic (up to 500 mm in length) and integrated (up to 900 mm in length), 10-40 mm in diameter, with a 3-6 mm thick wall, intended for the protection of thermocouples working in aggressive medium during the production and processing of aluminum and its alloys, zinc, silver.

Chlorine supply tubes

Up to 950 mm in length, up to 40 mm in diameter, with a 5-6 mm thick wall, intended to supply gaseous chlorine in the process of aluminum chlorine production. Service life - no less than 2 months in discrete processes and no less than 7 days in case of continuous use at aluminum melt temperature 700-750°C.

Ceramic protective screens

Designed for shielding an open spiral heater in small-sized electrovacuum furnace, used in prosthetic dentistry.

Crucibles - cylindrical, conical, high, wide, with rounded or flat bottom surface

Crucibles for smelting silver, gold, copper, aluminum

Press molds for the manufacture of heat-resistant glassware

Combined shears for cutting off glass gobs

Machine and equipment components

Cutting plates for milling and turning gray iron and nickel alloys

Fully ceramic and hybrid bearing elements

Wear-resistant bodies for grinding high-temperature solid aggressive masses

Wear- and impact-resistant components made Si₃N₄-based technical and structural ceramics developed at ORPE "Technologiya"
Properties	Units of measurement	Ceramic material grade
		OTM-904	OTM-906, OTM-914, OTM-917, OTM-922	OTM-918 *	OTM-913, OTM-919	ОТМ-907
		Manufacturing methods
		Reaction- bonded silicon nitride (RBSN)	Hot- pressed silicon nitride (HPSN)	Hot- pressed composite material Si₃N₄-BN (HPSNBN)	Sintered silicon nitride (SSN)	Compacted reaction- bonded silicon nitride (CRBSN)
mechanical Density	g/cm³	2,4-2,6	3,1 - 3,45	2,0-3,2	3,2 - 3,3	3,0 - 3,2
Bending strength at 20°С, 1300-1400°С	MPa	200 200	530 - 830 480 - 700	40 - 450 40 - 340	545 - 670 240 - 270	500 400(1000°C)
Stress intensity factor	MPa*м^1/2	2 - 3,5	6 - 9	2,5 - 3,0	5 - 5,7	5,0 - 6,0
Elastic modulus	GPa	164	242 - 294	20 - 197	250 - 280	164
Microhardness	HV, GPa		14 - 18		13 - 14	14
thermophysical Thermal expansion coefficient within 20-900°C	10^-6/C	2,6 - 3,2	2,8 - 3,7	2,8 - 3,6	3,2 - 3,6	3,2
Thermal conductivity	W/m *K	5 - 10	15 - 20	15 - 22		10 - 20
chemical Corrosion resistance in acids HCl, HF, H₂SO₄, in alkalies KOH, NaOH,etc.			high	high	high	high
operational Maximum operating temperature	C	1500	1300 - 1500	1300 - 1500	1300	1300
Application	Engine components, bearing elements, armor elements, wear- and corrosion-resistant components, lining
*Si₃N₄-BN - Ceramic material of varying composition (10-60 mass % BN) with the gradient of properties

Wear- and impact-resistant components made of SiC-based ceramics

Mechanical engineering, metallurgy, chemical and oil-producing industries

Crucibles for smelting metals

Rippers, inserts, nozzles

Rippers are used for blending pulp consisting of water, quartz and iron pyrite.

Inserts are used for smelting metals based on nickel and iron at 2000°C.

Centrifugal pump support assemblies, valves, nozzles, packing rings, gasket for pumps, pipelines, including those working in aggressive medium

Armored protection

Ceramic plates for the means of individual protection (armor elements, armor shields), monopanels

Chemical industry

Valves, nozzles, seal rings, gaskets for pumps, pipe-lines including those working in aggressive medium

Metallurgy industry, machine tool industry

Welding nozzles, gas nozzles and diffusers, electrical insulators, resistors, termistors

ORPE "Technologiya" has developed the process for the production of ceramic components for gas-operated welding appliances which possess high insulating properties, do not combine with molten metal, can easily be cleaned from solidified splashes under minimum mechanical action, are not liable to oxidation at 1000-1300°C for a long period of time, do not crack under temperature drop.

The use of ceramic components eliminates the need for an insulating bush, simplifies the holder design, increases the service life of the equipment, obviates the need for a large amount of conventional copper tubes used as nozzles.

SiC-based technical and structural ceramics
developed at ORPE "Technologiya"
Properties	Units of measurement	Ceramic material grade
		OTM-910	OTM-920	OTM-923	ОТМ-927
		Manufacturing methods
		Sintered and nitrided silicon carbide	Hot- pressed silicon carbide	Reaction- sintered silicon carbide	Slip-cast self-bonded silicon carbide
mechanical Density	g/сm³	2,5	3,0	3,1	3,0
Open porosity	%	15-25	0	0,2-1,0	0,3
Bending strength at 20°C, high temperature	MPa	260 230 (1400°С)	300 260 (1200°С)	180-240 200 (1300°C)	280
Elastic modulus	GPa	180	307
Microhardness	HV, GPa		30-43	21-31	22-27
Stress intensity factor	MPa*m^1/2	2,9	3,8	3,6	2,6
thermophysical Thermal expansion coefficient within 20-900°C	10^-6/С	4,4	4,8	4,2
chemical Corrosion resistance in acids HCl, HF, H₂SO₄			high
operational Maximum operating temperature	°C	1300-1600	1500	1500	1500
Application	Engine components, wear-, corrosion-resistant parts, armor elements

ФГУП "ОНПП "Технология"

Адрес предприятия:	ФГУП "ОНПП "Технология" Россия, 249035, г.Обнинск Калужской области, Киевское шоссе, 15
Телефоны:	(495) 234-39-95, (48439) 6-72-10 Русин Михаил Юрьевич - директор научно-производственного комплекса, (495) 996-34-62, (48439) 6-77-29 Хамицаев Анатолий Степанович - зам. директора научно-производственного комплекса
Факс:	(48439) 6-45-75
Internet:	http://www.technologiya.ru, http://www1.technologiya.ru
E-mail:

HIGH-TEMPERATURE THERMOSTRESSED PRODUCTS FROM CERAMIC MATERIALS BASED ON Si3N4