Surface Finishing of Ceramic Head Materials

Abstract

Typical head body materials for tape and disk drives are Ni-Zn ferrite, Mn-Zn ferrite, aluminum oxide-titanium carbide (70% Al2O3, 30% TiC), yttria-stabilized zirconia/alumina-titanium carbide composite, calcium titanate (CaTiO3), or Foroceram (a ceramized, photosensitive glass). (For more details, see Chapter 1.) These materials are produced by hot isostatic pressing to give high-density and excellent mechanical properties. These materials are selected for their excellent wear resistance. Ferrites are ferromagnetic materials and are most widely used for many tape and disk heads. Ferrites have a spinal structure and both single-crystal and polycrystalline structures are used in hot pressed forms. Al2O3-TiC and calcium titanate are used for composite disk heads. Al2O3-TiC is the material most commonly used for thin-film disk heads. Yttria-stabilized zirconia and aluminum oxide-titanium dioxide coatings (plasma sprayed) are also used on the air-bearing surfaces of some composite tape heads for desired wear resistance.