CHARACTERIZATION OF THE MICROSTRUCTURE IN TIB-WHISKER REINFORCED TI ALLOY MATRIX COMPOSITE

The ultrafine structure of the TiB-whisker reinforced Ti alloy matrix composite was studied by means of high-resolution electron microscopy (HREM). The TiB whiskers were embedded in the Ti alloy matrix uniforml y. The whiskers were in the form of elongated needles with a roughly h exagonal cross section. The aspect ratio of TiB of about 20 or higher can be achieved after hot extrusion. The TiB whiskers contain a modera te number of stacking faults on the (100)TiB plane. The Ti alloy matri x consists of alpha-Ti and beta-Ti. A superstructure in beta-Ti was de termined. Orientation relationships and atomic structure of the TiB/Ti interfaces were studied using HREM. The TiB whiskers bond well to the Ti alloy matrix and the TiB/Ti interfaces are atomically flat, sharp and free from any interfacial phase.