Al2O3 ceramics with submicron grain size

Topic

A leap in quality for alumina ceramics by new processing and microstructure

Alumina ceramics for many different applications are described by documented results of technological research. They are provided as granules for further processing, or as sintered specimens and prototypes with small grain sizes > 0.2 µm. A range of technological approaches like cold isostatic pressing, pressure filtration, and gel casting are available in combination with pressureless sintering to meet different requirements concerning the size of the bodies (up to about 100 mm), their grain size, hardness, and strength.

 

Applications

 

The whole spectrum known for dense alumina ceramics and new fields including e.g.

  • Sintered abrasives
  • Cutting tools
  • Bone implants
  • Thread guide elements
  • Sealing parts
  • Substrates
  • Ballisitc protection
  • High-strength transparent bodies

 

Advantages

 

The material associates the well-known advantages of traditional alumina ceramics like an exceptionally high chemical and thermodynamic stability with

  • An increase in strength by about 100 % with the consequence of an improved reliability
  • A significantly improved hardness and wear resistance
  • Low cost pressureless sintering

Additionally, the extremely fine grained microstructure gives a unique quality of polished surfaces.

Properties Typical data
Density g/cm³ 3,9 - 3,98
Grain size µm ≥ 0,2
Surface roughness Ra (after polishing) nm 1 - 2
Young´s modulus GPa 380 - 395
Bending strength MPa 650 - 900 (sintered pressureless)
Facture toughness KIC MPa m1/2 3,5 - 4,0
Vickers hardness HV 10 HK 0,1   2000 - 2400 (trad. Al2O3 + 35 vol-% TiC:2100) 2000 - 2400
Thermal conductivity W/mK 25