Resumo

AMIGO-BORRAS, Vicente; AMIGO-MATA, Angélica  e  HARO-RODRIGUEZ, Montserrat. TiAl Intermetallic Development by Using Conventional and High Densification Powder Metallurgy Techniques. Rev. Fac. ing. [online]. 2014, vol.23, n.36, pp.25-38. ISSN 0121-1129.

There is a growing demand for materials that offer services at high temperatures and low weight. However, these materials' manufacture is complex and expensive, particularly the cobalt-based superalloys and the titanium alloys. Within the latter, the Ti₃Al and the TiAl intermetallics are widely recognized to meet the current needs. However, due that these intermetallic casting and forging process, which have a better oxidation resistance at elevated temperatures, it becomes very complex and therefore starting from a pre-alloyed powder, can be tried to obtain practically some finished products at a reasonable cost. This paper analyzes the Ti48Al2Cr2Nb intermetallic powder processing variables' influence, by the conventional powder metallurgy techniques and the Spark Plasma Sintering, (SPS) in their microstructure and mechanical properties. Some samples are obtained at different sintering temperatures from the powders obtained by atomization. The influence on the mechanical properties is observed by its micro-hardness and compression resistance, and their microstructure is analyzed by an optical and scanning electron microscopy. The processing conditions show a large effect on the obtained microstructure, mainly in the α₂ phase formation, which accompanies the final mechanical properties. However, is in the maximum densification process, where the appropriate properties are obtained, which suggests that they are a clear alternative to the casting and plastic deformation's current processes.

Palavras-chave : TiAl Intermetallic; Powder Metallurgy; Spark Plasma Sintering; SPS technique; Mechanical properties.

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