Influence of crucible material on the level of contamination in TiAl using induction melting

Abstract

This paper describes the processing
\nresults of TiAl alloys melted in a
\ncontrolled atmosphere induction
\nfurnace, using crucibles made of
\ngraphite, calcia and zirconia stabilized
\nwith yttria, calcia and magnesia.
\nSamples were poured into graphite
\npermanent moulds or solidified and
\ncooled inside the crucible, in order to
\nsimulate the worst case scenario in a
\nmetal/refractory reaction using this
\nprocess.
\nThis paper presents segregation profiles
\nof residual elements and their influence
\non the micro hardness of different
\nphases and the extent of the “alphacase”.