Characterization of Al-Ni intermetallics around 30-60 at.%Al for TLPB application

A. URRUTIA; S. TUMMINELLO; S. ARICÓ; S. SOMMADOSSI

CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2013

0364-5916

Interest on the Al-Ni equilibrium diagram along the latest years is associated with the attractive properties of its intermetallic phases, such as high thermal stability, high corrosion resistant and high strength to density ratio. The Transient Liquid Phase Bonding (TLPB) is a technological process which can be apply to manufacture new pieces and to perform reparations. Morphology, composition profiles, growth kinetic and hardness as a function of temperature and composition of the intermetallic layers (ILs) were analyzed, especially focused on solid-solid interactions during isothermal annealing in reactive diffusion couples Ni/Al (800-1170°C). The study yields to the follow association of the Al-Ni IPs to the ILs: L1 (Al3Ni), L2 (Al3Ni2), L3 (Ni-poor AlNi), L4 (Nirich AlNi) and L5 (AlNi3). The composition ranges of L3 and L4 are 36-46 and 53-58 %at.Al, respectively. Martensitic transformation was found in the half thickness of L4 at 1170°C. The growth rate constants presented temperature dependence according to Arrhenius model. Vickers microhardness values decrease with annealing temperature and Ni concentration for ILs.