Field-activated sintering of blended elemental γ-TiAl powder compacts: Porosity analysis and growth kinetics of Al_3Ti

摘要

Various powder compacts with targeted compositions of TiAl and Ti_3Al were consolidated by field-activated sintering, specifi cally spark plasma sintering (SPS) at various temperatures, to examine phase growth under a superimposed electric field. While com pacts with a composition of TiAl showed significant porosity after sintering, Ti_3Al compacts showed no porosity. The porosity is attributed principally to volume changes associated with the formation of Al_3Ti and the Rirkendall effect. The kinetics underlying Al_3Ti growth during SPS are also explained.