Silicon Nitride Ceramic

Professional manufacturer to custom any silicon nitride ceramic parts based on your requirement .

Services for Silicon Nitride Ceramic Parts

Silicon nitride ceramic parts are one of our main engineering ceramics，our capabilities and services are as follows :

Machining accuracy control

Silicon nitride ceramic products are generally machined to complex geometries using diamond grinding tools. Silicon nitride ceramic parts have visual quality: No cracks, no dark dots, no contamination. Machining accuracy is as follow:
Processing accuracy: can be controlled to 0.002mm;
Cylindricity:best to be 0.005mm;Roughness:best to be Ra 0.2;
Thickness:Min 0.1mm; Smallest aperture: Min. 0.mm;
Concentricity: best to be 0.005mm; Flatness: best to be 0.002mm;
Straight flute: 0.1X100mm; Screw thread: Min. M2

Preparation process of silicon nitride ceramics

Silicon nitride ceramics prepared by different processes, each type of silicon nitride ceramics have different microstructures, which will lead to the performance of the difference is very large.

hot pressed sintering-HPS

Si3N4 and sintering additives were mixed and placed in a mould, surrounded by graphite paper and coated with BN, and placed in a sintering furnace to be prepared at high temperature and pressure.

General Si3N4 sintering atmosphere for N2, temperature in 1 600 ~ 1 900 ℃, pressure 15 ~ 40 MPa, insulation 1 ~ 4 h. This way of sintering out of the Si3N4 ceramics with high density, good mechanical properties.

gas pressure sintering-GPS

The GPS method is a sintering method that applies pressure through the use of nitrogen during the high temperature sintering process.

The pressure of the gas is generally in the range of 1 to 10 MPa to inhibit the decomposition and weight loss of Si3N4 in the high temperature sintering process and to ensure the densification of the prepared material.

pressureless sintering-PLS

Si3N4 powder and sintering aids are mixed, polyvinyl alcohol (PVA), etc. is added as a binder, and moulded under cold isostatic pressing (CIP) at 100-300 MPa, followed by sintering.

In the sintering process, the specimen is heated to 600 °C and held for a certain period of time to remove the binder, and then warmed up to the desired sintering temperature and held for a certain period of time.The PLS method is one of the most basic and simple sintering processes.

reactive sintering-RS

High-purity silicon powder is mixed with sintering additives, moulded by dry-pressing (DP), CIP, etc., nitrided for 8 h at 1 400 ℃ and under N2 atmosphere, and then heated to the required sintering temperature for sintering.

This method produces samples that do not shrink in volume, are dimensionally accurate, and are capable of preparing samples with complex shapes.

spark plasma sintering-SPS

A pulsed current added to the mould after placing the powder into the mould produces an extremely fast heating rate so that the α → β phase transition of Si3N4 can be completed very quickly.

The SPS method makes the sintering of Si3N4 materials fast and is one of the fastest sintering rates.

Si3N4 ceramic-related composites

Si3N4 ceramics are brittle and can be compounded with other materials to improve brittleness and enhance fracture toughness.

Properties that are insufficient in other materials, such as mechanical properties, oxidation resistance, wear resistance, etc., can also be improved after composite with Si3N4.

Main application of silicon nitride Ceramic Parts

Silicon nitride ceramic materials are characterised by high strength, high modulus, high temperature resistance, oxidation resistance and wear resistance, and are of particular value in working environments with high temperatures, high speeds and strong corrosive media. In addition, Si3N4 ceramics have excellent properties such as high thermal conductivity, thermal shock resistance, low dielectric constant and low dielectric loss, as well as good high-frequency electromagnetic wave transmission properties.

Mechanical

Silicon nitride ceramics are used as bearing balls, rollers, ball seats, moulds, new ceramic tools, pump plungers, shaft cores, etc.

thermal

Use of high-temperature resistance and low heat transfer: the manufacture of heating surfaces for engine components not only improves the quality of the diesel engine and saves fuel, but also improves thermal efficiency.

chemical

silicon nitride ceramics are used as wear and corrosion resistant parts. Such as ball valves, pump bodies, combustion carburettors, filters, etc.

metallurgical

Can make metal material processing moulds, such as tube mandrels, extrusion, wire dies, rolls, conveyor rolls, heat generator fixtures, thermocouple casing, metal heat treatment support parts, crucibles, aluminium conduits, aluminium package lining, etc.