화학공학소재연구정보센터
Advanced Powder Technology, Vol.28, No.11, 2974-2979, 2017
Induction-activated self-propagating, high-temperature synthesis of nickel aluminide
The self-propagating high-temperature synthesis (SHS) of nickel aluminide from elemental powders using an induction-activated method was investigated. The method could provide the high heating rates required for the surface layers of a compressed specimen to reach the ignition point, and develop a stable, exothermic reaction front traveling throughout the sample. The temperature history of the samples was recorded during the process to evaluate the combustion temperature; first light criterion was used to estimate the time-to-ignition. Temperatures higher than 2000 K were reached during the process, which shows that the released heat is sufficient for melting the NiAl product (T-m = 1911 K). As a result, high-density NiAl products were obtained. The effect of such parameters as sample green density, nickel particle size, and sample aspect ratio on the combustion temperature and ignition time was studied. XRD as well as SEM analyses showed that regardless of samples' initial conditions, the main phase detected in the products was NiAl. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.