Production of Al-Co-Ni Ternary Alloys by the SHS Method for Use in Nickel Based Superalloys Manufacturing


Alkan M., Sönmez M. Ş., Derin B., YUCEL O., ANDREEV D. E., SANIN V. N., ...More

HIGH TEMPERATURE MATERIALS AND PROCESSES, vol.34, no.3, pp.275-283, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 3
  • Publication Date: 2015
  • Doi Number: 10.1515/htmp-2014-0052
  • Journal Name: HIGH TEMPERATURE MATERIALS AND PROCESSES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.275-283
  • Keywords: Ni-based superalloys, Al-Co-Ni ternary system, SHS, centrifugal overload, COMBUSTION
  • Istanbul Technical University Affiliated: Yes

Abstract

In this study, Al-Co-Ni ternary alloys were synthesized, in order to obtain low-cost starting material for Ni-based superalloy production, by a self-propagating high temperature synthesis (SHS) both under normal gravity conditions (a = 9.81 m/s(2)) and under high gravity conditions (up to 1000 g-force) by using a centrifugal machine. The mixture of Co3O4-NiO powder were reduced by Al powder for the production of SHS alloys with the estimated compositions of 5-10 mass% Al, 20-65 mass% Co, 25-75 mass% Ni. The effect of green mixture compositions and centrifugal overload on combustion temperature, alloy/slag separations, chemical composition and microstructure of final alloys were investigated. The chemical analysis results showed that production of SHS alloys were achieved by having up to 86.12% of Co and 92.32% of Ni recoveries. The highest metal recovery value was obtained in SHS alloy with the estimated composition of 10%Al-65%Co-25% Ni by the addition of 20% Al2O3 into the green mixture. The metal/slag separation efficiency increased by increasing the centrifugal overload.