● High hardness ● High toughness ● High bending strength ● High wear resistance ● Low friction coefficient, ● Strong corrosion resistance ● Low thermal expansion coefficient ● Extremely high crack propagation resistance, high fracture toughness ● Self lubrication
Using self-developed silicon nitride powder formula and isostatic pressing forming of ball billets, precision fixtures, precision grinding and polishing are used to produce silicon nitride ball valves with high concentricity, high roundness, and smooth spherical surface
1. Self developed and self prepared silicon nitride powder
2. Dry pressing and isostatic pressing forming
3. Gas pressure sintering
4. Precision machining: flat grinding, outer diameter/inner diameter grinding, precision machining, grinding, polishing and grinding
5. Strict testing
● New energy ● Electricity ● Petroleum ● Chemical ● Metallurgy ● Mining ● Marine ● Aviation ● Sewage treatment, etc
Name/Characteristics | alumina | Zirconia | silicon nitride | Aluminum nitride | silicon carbide | boron nitride |
appearance | White or milky white or ivory | ivory | dark gray | brown | black | white |
density | 3.9 | 6.05 | 3.2 | 3.3 | 3.15 | 2.3 |
permittivity | 10 | 30 | 11 | 8 | 9.6 | 3.1 |
Thermal conductivity W/mk | 20~37 | 5-8 | 90-130 | 90~230 | 25-40 | 33 |
Thermal expansion coefficient(Negative sixth power of ten/K) | 4.5~8 (Negative sixth power of ten/K) |
8~11.5 (Negative sixth power of ten/K) |
3.2 (Negative sixth power of ten/K) |
4.5 (Negative sixth power of ten/K) |
4.8-5.2 (Negative sixth power of ten/K) |
15 (Negative sixth power of ten/K) |
Elastic modulus(Gpa) | 380 | 210 | 300~320 | 320 | 400~420 | * |
Poisson's ratio | 0.27 | 0.3 | 0.26 | 0.25 | 0.19 | * |
High temperature resistance | 500°~1700° | 500°~1700° | 800°~1300° | 1700° | 1700° | 2200° |
Acid and alkali corrosion resistance | strong | strong | strong | strong | strong | same as |
magnetism | not have | not have | not have | not have | not have | not have |
dimensional stability | Little change with temperature | Little change with temperature | Little change with temperature | Little change with temperature | Little change with temperature | Little change with temperature |
thermal shock resistance△T.℃ | 200 | 400 | 800 | 400 | 600 | * |
Operating centrifugal force | medium | more | small | small | small | small |
By product
Application requirement
Design and research
Optimization scheme
Strict essence
Precision drawing
piggyback
Select ingredients
Multiple forming
Fired blank
Grinding and polishing
Precision machining
Multiple gage
Professional survey
Qualified product
Package and ship
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