Processing of High‐Density Submicrometer Al2O3 for New Applications

Sintered corundum components with submicrometer grain sizes exhibit properties which enable numerous new applications. Wet powder processing is developed to associate minimum grain sizes at highest densities with the lowest population of macrodefects. A closest ratio of powder particle size and sintered grain size is important for obtaining most fine-grained microstructures. This target was approached best by using powders with particle sizes in the range of 100-200 nm rather than with smaller nanoparticles.

[1]  I. Chen,et al.  Deformation and Grain Growth of Low‐Temperature‐Sintered High‐Purity Alumina , 1990 .

[2]  Andreas Krell,et al.  Grain Size Dependence of Hardness in Dense Submicrometer Alumina , 1995 .

[3]  J. K. Montgomery,et al.  Thermoreversible Gelcasting: A Novel Ceramic Processing Technique , 2004 .

[4]  Hongwei Ma,et al.  Nanocorundum—advanced synthesis and processing , 1999 .

[5]  L. Gauckler,et al.  Shaping of ceramic green compacts direct from suspensions by enzyme catalyzed reactions , 1994 .

[6]  George C. Wei,et al.  Translucent Polycrystalline Alumina with Improved Resistance to Sodium Attack , 2001 .

[7]  A. Krell,et al.  Nanoindentation hardness of submicrometer alumina ceramics , 2001 .

[8]  Andreas Krell,et al.  The Influence of shaping method on the grain size dependence of strength in dense submicrometre alumina , 1996 .

[9]  A. Krell.  Improved hardness and hierarchic influences on wear in submicron sintered alumina , 1996 .

[10]  Mahmudur Rahman,et al.  Effect of grain size on wear behaviour of alumina cutting tools , 1997 .

[11]  W. Burger,et al.  Subcritical crack growth in Al2O3 with submicron grain size , 2003 .

[12]  Sidney Yip,et al.  Nanocrystals: The strongest size , 1998, Nature.

[13]  M. Furukawa.  Alumina ceramic tools , 1983 .

[14]  A. Krell,et al.  A new look at the influences of load, grain size and grain boundaries on the room temperature hardness of ceramics , 1998 .

[15]  Frederick F. Lange,et al.  Sinterability of Agglomerated Powders , 1984 .

[16]  Hayashi Koichi,et al.  Transmission Optical Properties of Polycrystalline Alumina with Submicron Grains , 1991 .

[17]  Hongwei Ma,et al.  Transparent Sintered Corundum with High Hardness and Strength , 2003 .

[18]  K. Morinaga,et al.  Fabrication of fine α-alumina powders by thermal decomposition of ammonium aluminum carbonate hydroxide (AACH) , 2000 .

[19]  A. Krell,et al.  Advances in the Grinding Efficiency of Sintered Alumina Abrasives , 2005 .

[20]  Rolf Apetz,et al.  Transparent Alumina: A Light‐Scattering Model , 2003 .

[21]  A. Krell,et al.  Alumina tools for machining chilled cast iron, hardened steel , 1999 .