Materials Synthesis and Development

Group

ATC: TiC-reinforced Al2O3 ceramics with high carbide content

Topic

Improved quality by new ceramic processing

Pressureless sintered or hot-isostatically pressed alumina ceramics with high contents of TiC or Ti(C,O,N) are characterized by a microstructure where the grain boundaries are free of any amorphous films. Adjusted compositions and technological approaches are developed to meet special requirements in technical applications and are used to produce individual prototypes and small series.

 

Applications

 

  • Sliding head substrates in data storage systems
  • Equipment for sinter forging (e.g. glass lenses with high quality of surfaces)
  • High precision wear-resistant parts (e.g. chucks for the automatic change of tools)
  • Cutting tool inserts
  • Substitution of Al2O3 to enable advantageous electroerosive processing of parts

 

Advantages

 

An important merit of the developed technology is the possibility to achieve improved properties without expensive hot pressing. The advantages of the material:

  • Compared with commercial pure alumina ceramics are an increased hardness and strength
  • Compared with carbide-reinforced zirconia it is its the high oxidation resistance. The production of parts with complex geometries is enabled by the easy electroerosive processability of the electrically conducting material
Properties Typical data
  sintered sintered + HIP
Density g/cm³ 4.29 - 4.34
Grain size µm ≥ 0,5
Sourface roughness Ra (after polishing) nm 5 - 7
Young´s modulus GPa GPa 360 390
Bending strength MPa 600 - 700 800 - 900
Facture toughness Kic MPa m1/2 5 - 6
Vickers hardness HV 10   1900 - 2100 2100 - 2300
Electrical resistance m Ω cm 0,7
Thermal conductivity W/mK 21