Abstract
ABSTRACT
In order to improve the mechanical properties of TiAl intermetallic compound by combustion synthesis, it is also effective to synthesize composite Ti – Ni – Al intermetallic compound by the addition of Ni. However, in combustion synthesis of Ti – Ni – Al system, difficulty of reaction control of elemental Ti/Ni/Al mixed powder brought meltdown or poor sintering to the synthesized product. In this paper, by developing two-step combustion synthesis process, fabrication of Ti – Ni – Al intermetallic compound was examined. Namely, in 1st-step combustion synthesis, TiAl and Ni3Al compound powders were composed. In 2nd-step combustion synthesis, by mixing TiAl, Ni3Al, Ti, Ni, and Al powders, Ti – Ni – Al intermetallic compound was synthesized by the combustion synthesis reaction. By using the two-step combustion synthesis, dense Ti – Ni – Al intermetallic compound could be fabricated. The microstructure of the product consisted of about 20 µm crystal grain. From SEM – EDX analyses, it was found that the compound phases were TiNi2Al phase (τ4) and TiNiAl2 phase (τ2). Since Ti – Ni – Al intermatallic compound can be synthesized easily by the two-step combustion synthesis, development of future investigation of the ternary intermetallic compound material is expected.
