Fabrication of Ni-Al Intermetallic Compound Layer on Spheroidal Graphite Cast Iron Substrate by SHS Reaction

Abstract

  The coating layers of Ni-Al Intermetallic compounds were prepared on spheroidal graphite cast iron substrates by the applying of self-propagating high-temperature synthesis (SHS) reaction, and simultaneously bonded on substrates by the excessive heat of reaction. The results obtained were as follows. (1) The synthesizing reactions begin at about 873K before the melting point of Al. (2) The reaction layer consists of Ni₃Al, NiAl, Ni₂Al₃ and Ni phases, and it sufficiently bonded on base metal. (3) With the powder compact of Ni-60 at % Al, Ni solid solution almost disappeared in the reaction layer, and then the hardest phase, Ni₂Al₃ of Ni-Al intermetallic compounds was produced.