Lägesrapport - Nya sammansatta keramer

Samples of Al2O3 have been produced by Spark Plasma Sintering. As a start, a material that was easy to sinter, an (a-Al2O3 powder with a mean particle size of 400 nanometer, was chosen. After compaction the grain sizes was measured to be 500 to 1000 nm. Vickers indentation gave a hardness of 21-23 GPa (Hv) and a fracture toughness of 3.5±0.5 MPam½ (KIc). Introductory studies on a gradient material of titanium and titandiboride (Ti-TiB2) have been performed, were the separate layers individual sintering parameters have been studied. Next step will be to join all layers into a gradient material. Powder mixtures of 80% Ti and 20% TiB2 showed a very interesting microstructure, where in situ TiB-whiskers were formed. The work has been done as a collaboration with the project "Gradient and matrix materials".