MAによる金属粒子の扁平化とAl_2O_3複合材料への応用 Study on Flake-Forming Behavior of Metal Powders by MA and Application of the Flaky Metal Powders to Al_2O_3 Composites
New simultaneous toughening and strengthening method for Al<SUB>2</SUB>O<SUB>3</SUB> composites has been reviewed. The flake-forming behavior of refractory metal powders such as Mo, Ta and Nb by MA process, and three-point flexural strength and fracture toughness of Al<SUB>2</SUB>O<SUB>3</SUB> composites reinforced with flaky Mo particles have been investigated. The flake-forming behavior of Mo powders mixed with Al<SUB>2</SUB>O<SUB>3</SUB> powders becomes prominent with increasing Mo particle size, while remaining almost independent of Mo volume percent. The fracture toughness increases with increasing Mo particle size which corresponds to an increase of the flake-forming tendency of these particles. Furthermore, the fracture toughness and flexural strength can be simultaneously improved by increasing the volume percent of flaky Mo particles. The microstructural observations indicate that the improvement in fracture toughness may be due to plastic deformation of Mo particles at a crack tip and crack-deflection or crack-bridging which are accelerated more by the flaky rather than the small. spherical shape.
粉体および粉末冶金 43(6), 705-711, 1996-06-15
Japan Society of Powder and Powder Metallurgy