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Aluminium-lithium (Al-Li) alloys have gained prominence in the aerospace industry in recent years as structural materials. This is due primarily to their mechanical properties, such as high specific strength and modulus, and low density. Development of Al-Li/ceramic composites is currently being investigated to enhance the higher service capabilities of this material. Processing of Al-Li/ceramic composites by the powder metallurgy (PM) route offers many advantages over ingot casting such as a well-dispersed reinforcement distribution and easy handling. However, the PM route suffers from agglomeration of the ceramic reinforcement when the particle size is below 2.5 μm. This paper reports the development of several methods of mixing submicron ceramic powders with Al-Li to obtain a uniform distribution of the reinforcement. Among the methods used were mixing in a fluidized bed, ball milling, spray drying and mixing the metal powder with a ceramic slurry.

Ti3Al (α2) and TiAl (gamma) are of technological importance to aerospace-type applications due to their attractive high temperature properties. Plasma spraying of fine powder and coatings of Titanium aluminides was carried out to examine the effect of spray parameters on the microstructure and properties of these materials. Characterization of the powders and coatings was performed using the scanning electron microscope (SEM) and image analyzer. The results show that while plasma spraying is a viable process for forming coatings and fine powders of Ti-Al, the initial particle size of the powder feedstock and the plasma gas composition play an important role in successful processing of the material.