A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand) in partial fulfilment of the requirements for the degree of Master of Science in Engjneering Johannesburg, 1994 / Recent international investigations into new advanced materials have shown that the intennetallic compound, RuA1, possesses prormising characteristics for high-temperature use in corrosive environments. In order to optimise production of this alloy, an understanding of the Ru-A1 system is necessary. [Abbreviated Abstract. Open document to view full version]