Heat Treatment Study of γ + α2 Ti Aluminides Obtained through Reaction Synthesis and Hot Deformation

Abstract

AbstractTi aluminides based on γ + α2 has industrial importance due to its high temperature properties coupled with low density. Processing difficulty involved in this alloy has limited its application. Alternate processing route like reaction synthesis in combination with isothermal hot working has lot of potential. Further, heat treatment of hot worked material governs the properties of the alloy. In the present paper, heat treatment of reaction synthesized plus hot worked material has been studied to obtain desirable microstructure and phases. Five alloys of Ti48Al2Cr2Nb with minor addition of boron and Ni-P coated boron is made with two different particle size of Ti powder. Homogenized and worked alloy samples are heat treated to obtain two-phase microstructure useful for high temperature application. Heat treated samples are characterized for individual phases through optical microscopy, hardness measurement and electron microscopy. An attempt has been made to study the role of boron on development of various phases and microstructure.