EFFECT OF SILICON ON THE ELEVATED-TEMPERATURE PROPERTIES OF A TI3AL BASE ALLOY

Additions of silicon in the range 0.0-1.0at.% were made to a Ti(3)AL b ase alloy Ti-25Al-14Nb-1Mo in order to study its effect on the creep p roperties of this ahoy. The alloys were studied under three different microstructural conditions achieved by varying the cooling rates from the beta phase field. The addition of silicon did indeed reduce the pr imary creep strain and the steady state creep rate in all the alloys. Both the primary creep strain and the steady state creep rate showed m inima at 0.7% silicon and exhibited relative insensitivity to cooling rate. The yield strength also showed a maximum at around this composit ion.