Specialty Ceramics

Saint Gobain Specialty Ceramics' products allow customers to solve tough problems in thermal and chemical processing, industrial metrology, temperature sensing, brazing, mechanical seals, semi-conductor processing, sandblasting, and renewable energy generation applications. Specialty Ceramics' portfolio consists of more than a dozen products, sold as well-known brands: Hexoloy® materials, Norbide® nozzles, Noralide® materials, Silit® materials, Advancer® refractory parts, Alundum® materials, Magnorite® materials, Durafrax® materials and Lithafrax™ powders.

At Saint Gobain, we use competence in design and precision manufacturing to deliver engineered solutions to customers in global automotive, chemical, aerospace, non-ferrous metals, industrial pumps and sealing industries, as well as OEM equipment makers and machine shops.

Key Datasheets

Specialty Ceramics Applications

Discover our Solutions for Specialty Ceramics applications

Thermocouple Protection

Temperature sensors provide essential data for control of industrial manufacturing processes. Sensors are often exposed to harsh environments and therefore must be protected to enable reliable and long-term operation. Hexoloy® SiC tubes provide unmatched protection against corrosion, abrasion and erosion from hot fluids and particulates without compromising sensor accuracy. High thermal conductivity of Hexoloy SiC tubes allow fast response of the sensors. It is ciritical to electrically insulate the thermocouple wires inside the thermocouple. Alundum (fused Alumina) and Magnorite (fused MgO) 'Crushable Insulators' provide insulation in Mineral Insulated Metal Sheath (MIMS) thermocouples and cables.

Thermocouple Protection

Specialty Ceramics Products for Temperature Sensors
	OD	ID	Length	Application & Advantages
Closed One End Hexoloy SE SiC Protection Tubes	9.5 - 25.4 mm (3/8" - 1-1/2“)	6.35 - 25.4 mm (1/4" - 1")	152 - 1 372 mm (6" - 54")	Advantage: Thin wall, fast response, superior thermal shock resistance, works up to 1650ºC in oxidizing atmosphere Application: Thermocouples & Thermowells for Non-Ferrous Metals, Glass, Cement, Chemicals, Molten Salts
Fused Alumina Crushable Insulator	0.56 - 12.7 mm (0.022" - 0.5")	0.18 - 7.24 mm (0.007" - 0.285")	101.6 mm (4") max	Advantage: High electrical insulation; not sensitive to humidity Application: MI thermocouples & cables
Fused MgO Crushable Insulator	0.56 - 12.7 mm (0.022" - 0.5")	0.18 - 7.24 mm (0.007" - 0.285")	101.6 mm (4") max	Advantage: High electrical insulation Application: MI thermocouples & cables
Fused MgO Insulating Grain	Milled or Unmilled grains			Advantage: High electrical insulation Application: MI thermocouples & cables

High Accuracy CMM & Motion Control

Saint Gobain SiSiC and NSiC products allow high precision, accuracy and speed in industrial metrology equipment, such as CMM and Positioning Equipment, due to their high specific stiffness, lightweight, low thermal expansion and high thermal conductivity. The unique combination of several key properties of silicon carbide makes it a superior choice to other materials, including alumina ceramic, aluminum, steel and granite. Key applications include CMM bridges and Z axis; guide rails and air-bearing stages.

Silicon carbide offers many advantages over traditional ceramic materials:

Lightweight (~20% less)
High specific stiffness (~25% higher)
Low thermal expansion (~50% less)
High thermal stability

Read Article Download Brochure

Product Choices for Metrology Equipment
	Density (g/cc)	Specific Stifness	Thermal Conductivity (W/mK)	Thermal Expansion (10^-6/K)
Granite	2.8 - 2.9	21-32	3	5 - 7
Alumina	3.95	96	20	8
Steel	7.88	27	47	12
Aluminum	2.69	26	204	22.5
Advancer (NSiC)	2,8	86	20	4,4
Silit (SiSiC)	3,0	117	140	4,5
Hexoloy (SSiC)	3,10	132	125	4,0

Shell & Tube Heat Exchanger

For more than 30 years, Hexoloy® SE silicon carbide tubes have provided the most reliable and preferred choice for shell & tube heat exchangers used in fine chemicals and pharmaceutical industries. This success is based on virtually universal corrosion resistance, high thermal conductivity, extremely high hardness and mechanical strength of Hexoloy.

Hexoloy SE tubes are available in 12.7 mm, 14 mm, and 19 mm outside diameter and lengths up to 5 m. Each tube is proof tested to 186 bars (2700 psi). Hexoloy SA SiC tube sheets are also available as per OEM design.

See Datasheet

Corrosion Resistance of Different Materials Against Chemicals
*Test Time: 125 to 300 hours of submersive testing, continuously stirred.
Test Environment* Conc. Reagent (Wt%)	Corrosive Weight Loss (mg/cm² yr)
Test Environment* Conc. Reagent (Wt%)	Temp. (°C)	Hexoloy® SA (No Free SiC)	Reaction Bonded SiC (12% SiC)	Tungster Carbide (6% Co)	Aluminum Oxide (99%)
98% H₂SO₄	100	1.8	55.0	>1000	>65.0
50% NaOH	100	2.6	>1000	5.0	75.0
53% HF	25	<0.2	7.9	8.0	20.0
85% H₃PO₄	100	<0.2	0.5	>1000	7.0
45% KOH	100	<0.2	>1000	3.0	60.0
25% HCl	70	<0.2	0.9	85.0	72.0
10% HF plus 57% HNO₃	25	<0.2	>1000	>1000	16.0

Chemical Processing

Hexoloy® sintered silicon carbide has been successfully used for over 30 years in chemical processing applications, such as seal face and seat in mechanical seals used in pumps, tubes in shell & tube heat exchangers, thermowell protection tubes, valves for handling mining slurries, sparger tubes, Impellers for mixing, raschig rings, and chemical reactor vessels. Hexoloy material is highly corrosion resistant in contact with liquid and gaseous chemicals of a broad range of pH.

Corrosion Resistance of Different Material Against Chemicals
*Test Time: 125 to 300 hours of submersive testing, continuously stirred.
Test Environment* Conc. Reagent	Corrosive Weight Loss (mg/cm² yr)
(Wt%)	Temp. (°C)	Hexoloy® SA (No Free SiC)	Reaction Bonded SiC (12% SiC)	Tungsten Carbide (6% Co)	Alminum Oxide (99%)
98% H₂SO₄	100	1.8	55.0	>1000	65.0
50% NaOH	100	2.6	>1000	5.0	75.0
53% HF	25	<0.2	7.9	8.0	20.0
85% H₃PO₄	100	<0.2	8.8	55.0	>1000
70% HNO₃	100	<0.2	0.5	>1000	7.0
45% KOH	100	<0.2	>1000	3.0	60.0
25% HCl	70	<0.2	0.9	85.0	72.0
10%HF plus 57% HNO₃	25	<0.2	>1000	>1000	16.0

Semiconductor Wafer Processing

Hexoloy® SA and SG components, such as vacuum chucks, chemical mechanical polishing (CMP) blocks and wafer carrier trays, are used in semiconductor wafer processing equipment. Hexoloy material’s thermal expansion matches to silicon, high elastic modulus, and chemical inertness ensures the economic benefits of maintenance and reuse, and high thermal conductivity for even, rapid heating of the silicon wafer.

Hexoloy® SiC provides outstanding shape stability, wear & chemical resistance, and thermal properties for the production of semiconductor components.

Advantages:
The thermal expansion of Hexoloy® – close match to silicon - coupled with high thermal conductivity allows even and rapid heating of the silicon wafer. Hexoloy® high elastic modulus, and chemical inertness ensures the economic benefits of maintenance and reuse.

Sintered Silicon Carbide Materials for Semi-Conductor Processing
Material	Density (g/cc)	Flexural Strenght (MPa)	Electrical Resistivity (ohm-cm)	Thermal Conductivity (W/m.K)	Elastic Modulus (GPa)
Hexoloy SA (Sintered SiC)	3.15	380	10²-10⁶	125	410
Hexoloy SG (Sintered SiC with free Carbon)	3.0	311	1	118	376

Sandblasting

The extremely high hardness of sintered silicon carbide and boron carbide make these materials excellent choices for nozzles in high wear applications. Hexoloy® SA SiC and Norbide® B₄C nozzles outlast WC and are successfully used in sandblasting and atomization applications.

Key Datasheets

Erosion Resistance of different materials:

Thermal Processing

Owing to its very high thermal conductivity, low thermal expansion, lightweight and high strength at high temperatures, Hexoloy® SA sintered silicon carbide products are an excellent choice for thermal processing applications. Examples include rapid thermal treatment of fibers, crystals; components of high temperature anaytical equipment (dilatometers and TGA).

Key Properties of Sintered Silicon Carbide Material
	Density	Coefficient of Thermal Expansion (x10^-6/K)	Flexural Strength (Mpa)	Thermal Conductivity (W/m K)	Elastic modulus (Gpa)
Hexoloy SA (Sintered SiC)	3.15	4.0	380	125	410

Specialty Ceramics Application, Labware | Saint-Gobain

Labware Operations

Our Labware is designed for laboratory operations involving ignition, weighing, melting, incineration, combustion, extraction or filtering.

Our refractory products are ideal for conventional laboratory operations. Made of Alundum® fused aluminum oxide grains produced in electric arc furnaces, our standard labware is manufactured to various degrees of quality according to designated applications.

Alundum® labware (made of the purest 99% aluminum oxide in its basic state) melts at 2054°C. With the addition of ceramic bonds and proper treatment, our labware has many unusual and useful properties.

Our labware products include combustion boats with and without handles, dishes, thimbles, filters discs & cones, and crucibles & covers.


	Grade	Approx. Particle Retention Size	Apparent Porosity	Composition	Maximum Use Temperature	Coeff. of Thermal Expansion (30-1500°C)	Approx. Electrical Resistivity	Effect on Atmospheres
Alundum® AN-788	Fine	0.1 micron	35%	91% Al₂O₃	1450°C	8.6x10-6	130.0 Megaohms at 530°C 16.0 Megaohms at 730°C 5.3 Megaohms at 890°C 1.5 Megaohms at 1020°C	Oxidizing: None Reducing: Reduction of bond constituents above 1400°C Effect on Acids: None except HF and concentrated H3PO4 Effects of Alkalies: None except strong hot caustic solutions and fused alkalies
Alundum® AN-889	Medium	5.0 microns	42%	85% Al2O3	1450°C	8.6x10-6
Alundum® AN-485	Coarse	20.0 microns	47%	85% Al2O3	1450°C	8.6x10-6
Zirnorite® YN-756	--	--	25%	92.6% ZrO2 SiO2	1590°C	5.5x10-6	High

Mechanical Seals

Saint Gobain pioneered the use of sintered SiC as a seal face in automotive water pumps in the early 1980s. Since then, Hexoloy® SiC has become the leading choice for mechanical seal face and seat material in automotive, chemical, oil & gas, and nuclear power industries. This success is driven by the exceptional hardness, strength, and chemical resistance of Hexoloy sintered SiC. Seal rings for nuclear reactor coolant pumps are also available in Noralide® Si₃N₄ material.

Hexoloy SP SiC Datasheet

Sintered Silicon Carbide Products for Seal Applications
Area	Unground Seal	Unground Seal Blanks	Ground Seals
Hexoloy SA	Up to 16” O.D.	Up to 16” O.D.	Up to 16” O.D.
Hexoloy SP	Up to 16” O.D.	Up to 16” O.D.

Our Products

Discover our specialty ceramics products

Thermocouple Protection Tubes

Hexoloy® SE sintered silicon carbide thermocouple protection tubes are extruded and closed on one end. Tubes are produced in standard lengths and diameters as shown in the table below. Longer custom lengths and large diameters are available upon request. The closed end is typically round, however, larger diameters, for example 1.5” tubes, have pointed tip. Hexoloy® SE tubes have thin walls, compared to other ceramic materials, enabling fast thermal response to the sensor.

Learn More on Hexoloy Sensor Tubes

Nitride bonded Silicon Carbide (NB SiC) tubes are an economic choice to Thermocouple sensor OEMs. These tubes can be produced to a large range of OD, ID, with several options for mounting. NB SiC does not contaminate non-ferrous melts, like cast iron tubes. It also finds application in temperature measurement of heat treating furnaces.

Advantage:	Application:
< 12% porosity (surface porosity < 1%) Max service temperature: 1450°C Economic choice among different types of SiC	Non-ferrous furnaces Heat Treatment furnaces

Silit®SK, Siliconized SiC, material can be used as Thermocouple protection tubes, closed on one end. A wide range of diameters (20 m – 80 mm) can be produced with lengths up to 2 m. Tubes with flanges and / or holes are available.

Advantage:	Application:
High resistance to oxidation High thermal shock resistance Extreme high strength stability of shape up to maximum application temperature	Cooling Tubes Thermocouple Protection tubes Radiant Tubes in kilns / furnaces

Thermocouple Protection

Crushable Insulators

Crushable insulators are available in Alundum® 99.8% fused Al₂O₃ and Magnorite® 99.5% fused MgO grades. Insulators are “threaded” on thermocouple conductor wires and inserted inside a seamless metal tubing. The entire assembly is them swaged or drawn down to desired dimensions. During swaging the insulators crush readily into a powder, compacted around the thermocouple wires, providing electrical insulation resistance. OD is available from 0.022” (0.5 mm) to 0.5” (12.7 mm). Hole diameter is available in the range 0.007” (0.18 mm) to 0.069” (1.75 mm). The number of holes in an insulator ranges from 1 to 6. Insulator lengths are available in 1” increments up to 4” maximum. See attached brochure for detailed information on chemical purity, sizes, tolerances, and inspection.

Advantage:

High electrical insulation

Applications:

MIMS thermocouples & MI cables

Read Brochure

Specialty Ceramic Products, Heat Exchanger tubes and tube-Sheets | Saint-Gobain

Heat Exchanger Tubes & Tube-Sheet

Heat Exchanger Tubes & Tube Sheets

Hexoloy® SE sintered silicon carbide tubes are extruded product available in 8 mm, 12.7 mm, 14 mm, and 19 mm outside diameter, and lengths up to 4.5 m. Tubes are used in conjunction with tube sheets (PTFE, PFA lined steel, or SiC) and a series of baffles placed inside a steel or glass shell. Tubes go through a rigorous quality control and inspection process, including hydro-testing of every tube at 165 - 186 bars. Hexoloy® SE tubes have thin walls resulting in high heat transfer in a heat exchanger application.

Hexoloy® SA silicon carbide tube sheets are available in a range of diameters and thickness. Contact your Saint Gobain Application Engineer for details.

Specialty Ceramic Products, Seal Tubes, Blank and Faces | Saint-Gobain

Seal Tubes, Blanks & Faces

Hexoloy® SA sintered silicon carbide seal tubes are available in a wide range of OD and ID combinations. Typical length of the seal tube is 12”, through 6” tube is also available. Seal tubes are unground and sold with “as-fired” tolerances.

Low volume Hexoloy® SA sintered silicon carbide blanks are available in a range of OD and ID combinations. Typically the blanks are <1” thick, though thicker blanks are available. High volume blanks (qty >500 pcs) are available as dry-pressed product up to 5.125" OD. Blanks are typically unground and sold with “as-fired” tolerances.

Ground seal faces are available in Hexoloy® SA silicon carbide and Noralide® silicon nitride materials. Both materials are fine-grained and produced to near theoretical density. These attributes impart excellent wear resistance, a key requirement for seal face products. Both materials possess excellent resistance to corrosion from chemicals with a broad range of pH. Seal faces are produced to custom drawings with high quality surface finish.

Applications:

Seal faces for mechanical seals used in industrial pumps.

Advantages:

Exceptional hardness
Chemically inert to a broad range of chemicals

Specialty Ceramic Products, Beams | Saint-Gobain

Beams & Rods

Beams are available in at least three different materials, namely Silit® SKD - siliconized silicon carbide; N-Durance® nitride bonded silicon carbide, and Hexoloy® SE sintered silicon carbide. Beams can be made in large selections of cross-sections, wall thickness and lengths (up to 4 m) using slip-casting or extrusion process. As-fired beams can be used "as-is" or finished to customer’s tolerances. Applications include structural support in high temperature processes, and metrology equipment.

See Hexoloy SE Beams Brochure See Silit SKD Brochure

Hexoloy® SA and SE grades of Sintered Silicon Carbide are available as Rods for use in variety of thermal – mechanical applications. Extruded Rods are available in diameters ranging from 0.125” to 0.53”. Diameter tolerance is + - 2% or 0.01” minimum. Straightness is 0.005 inch / inch maximum.

Advantages:

Excellent thermal
Mechanical and chemical stability for use as small precision components

Applications: 

High precision components in laboratory and industrial equipment

See Hexoloy SE SiC Rod Bulletin

Nozzle

Nozzles are available in two materials; Hexoloy® SA silicon carbide , and Norbide® B₄C boron carbide. Both materials have exceptional intrinsic hardness which enables superior wear and abrasion resistance from a wide range of abrasive solid and liquid media. In addition, B₄C is lighter weight compared to all other choices for nozzles.

Typical uses include:

Blast nozzles
Monument nozzles

Process Tubes

Hexoloy® SA sintered silicon carbide is an excellent material for “process” tubes in a wide range of thermo-chemical environments. Tube diameter can range from 1” (25 mm) to 15” (381 mm), and lengths up to 48” (1.2 m). Longer tubes (up to 16’) are available as assemblies using a proprietary bonding process.

Process tubes can also be made through extrusion (Hexoloy® SE) when long tubes (up to 5 m) are desired without joints.

Advantage:

High oxidation resistance up to 1650C in air
Excellent corrosion resistance against a broad range of chemicals
High mechanical strength and erosion / abrasion resistance
Superior resistance to thermal cycling

Applications:

Process tubes
Sparger tubes
Sensor tubes

Tiles

Hexoloy® SA Sintered Silicon Carbide Tiles are available in sizes ranging from 2”x2” to 7”x7” with thicknesses from 0.1” to 0.75”. Hexagon shaped tiles are also readily available. One surface can be polished.

Advantages:

Excellent thermal
Mechanical and chemical stability for use as small precision components

Applications:

Industrial and research equipment.
Aerospace
Semi-conductor

See Tiles Bulletin

Custom Shapes

A wide range of custom shapes are available in Hexoloy® silicon carbide SA and SE grades. Examples include impellers, crucibles, telescope mirrors and supporting structures, sparger tubes, raschig rings (packing for distillation columns), furnace belts and so on. This capability comes from nearly 40 years of experience in precisely controlled raw materials, forming, shaping green parts with CNC equipment, sintering and finishing to tight tolerances.

Specialty Ceramic Products, Lithafrax | Saint-Gobain

Lithium Aluminum Silicate Based Powder

Lithafrax® lithium aluminum silicate based powder was developed for use as a low thermal expansion inorganic filler in a wide range of materials. Examples include resins, plastics, urethanes, sealing glass, coatings, glaze, and metal paste. The key advantage from Lithafrax powder is in controlling thermal expansion of the final product. Lithafrax® powders have been successfully used in aerospace, military, automotive, electronics, and building & habitat markets.

Advantages: 