One of the limitations of current high-temperature
titanium alloys of the near-c~ type is the poor
oxidation resistance at temperatures above about
600 °C. However, titanium-aluminium alloys in the
composition range where the aluminides Ti3A1 (o/2)
and TiA1 (g) form show better oxidation resistance,
particularly in the case of TiA1. The results reported
here form part of an investigation of the formation
of titanium aluminide layers on a titanium substrate,
as an approach to improving oxidation resistance
and erosion resistance: Laser alloying, involving
feeding aluminium powder into a laser-generated
melt pool at various rates, has been used to produce
layers with aluminium contents ranging from about
20 to 80 at % [1]. Details of the constitution and
fine-scale microstructural features of the layers
resulting from their rapid solidification have been
reported elsewhere [2-4]. In the present work
exploratory oxidation tests were made of three
alloyed layers, namely Ti-30 at % A1, Ti-43 at %
A1 and Ti-55 at % A1, including compositional and
microstructural