YDTech™ suppliers of ceramic spheres, aluminium oxide balls, zirconium oxide balls! manufacturers of ceramic balls, silicon nitride spheres, Si3N4,Al2O3,ZrO2 balls in china.
ceramic balls include silicon nitride(Si3N4) balls, aluminium oxide(Al2O3) balls and zirconium oxide(ZrO2) balls.
silicon nitride ceramic balls deliver unsurpassed performance in critical components such as hybrid bearings. Specified for use in such high-technology industries as aerospace and defense, high-spec ceramic balls feature these advanced characteristics:
Lightweight Silicon Nitride weighs 60% less than steel which reduces centrifugal force, skidding and wear under high speed and acceleration.
superior surface finish, Ra 0. 1 7-0.25 maximum micro inches may extend L-10 life to as much as 100 times that of steel bearings.
high temperature Hardness is twice that of steel. these all-ceramic balls retain their strength and hardness up to 1800 degrees F.
silicon nitride is further characterized by its low density of 3.2 g/cc, high flexural strength of 1.0 GPa, and fracture toughness of 6 MPa/M2.
these outstanding properties, together with manufacturing standards regarding sphericity, diameter tolerance, and surface finish, make silicon nitride balls ideal for high performance ball bearings.
zirconia oxide is superior in corrosive and erosive environments. Being lighter in weight also helps reduce damage to mating components.
alumina oxide ceramic balls have proven performance in wear, heat and corrosive environments as well as in maintaining dimensional stability at temperatures up to 2000 F. Alumina resists oxidation and is tolerant to water, salt solutions, and many chemicals and acids
structural ceramics Vs steels
| properties | Si3N4 | ZrO2 | Al2O3 | SiC | 52100 | 440C | |||
| density(g/cm3 | 3.26 | 6.05 | 3.93 | 3.2 | 7.85 | 7.85 | |||
| water absorption(%) | 0 | 0 | 0 | 0 | 0 | 0 | |||
| flexible mold(GPa) | 300 | 210 | 340 | 440 | 208 | 200 | |||
| expansion coefficient(10-6K) | 3.2 | 10.5 | 8.5 | 3.0 | 12.5 | 17 | |||
| hardness HV(GPa) | 16 | 12 | 16.5 | 22 | 7 | 7 | |||
| fracture toughness(MPam1/2) | 7.0 | 10 | 4.2 | 3.9 | 20 | 25 | |||
| flexural strength(GPa) | 720 | 950 | 310 | 450 | -- | -- | |||
| compressive strength(GPa) | 2500 | 2000 | 2200 | 1800 | -- | -- | |||
| poisson's ratio | 0.25 | 0.3 | 0.22 | 0.17 | 0.3 | 0.3 | |||
| thermal conductivity(W/mK-1) | 20 | 2 | 26 | 120 | 40 | 40 | |||
| specific resistivity(Ωmm/m) | >1010 | >1015 | >1016 | >1.3 | 0.1-1 | 0.1-1 | |||
| temperature(°C) | 1400 | 750 | 1750 | 1550 | 300 | 150 | |||
| ceramic balls silicon nitride(Si3N4)ceramic beads zirconium oxide(ZrO2) aluminium (Al2O3) | |||||||||
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