Using alumina nanopowder as cement in bonding of alumina ceramics

The high sinter activity of alumina nanoparticles was used to bond coarse-g rained corundum ceramics. The employed nanopowder was generated by the evap oration of solid corundum rods using the radiation of a Nd:YAG-laser follow ed by condensation of the vapour in a controlled atmosphere. Some nanopowde r was sandwiched between corundum disks followed by bonding of this assembl y at an uniaxial pressure of 80 MPa and a temperatures of 1300 degrees C, I n order to determine the structure and the strength of the joints HR-SEM in vestigations and four-point bending tests were carried out. To determine th e influence of strong agglomerates in the as produced nanopowder and the bo nding behaviour some of the nanopowder was ball-milled for a short time bef ore bonding. The results are compared.