Role of Ru in a new phase formation in an Ni-base single crystal superalloy with high Cr content

The role of Ru in a new phase formation in an Ni-base single crystal superalloy with high Cr content is investigated. The addition of 3 wt.% Ru leads to the formation of a new phase, which is judged as beta-NiAl phase by TEM analysis. The formation mechanism of the beta-NiAl phase is examined in depth. The particular solidification path caused by the beta-NiAl phase is defined and the promoting effect of Ru on the beta-NiAl phase is explained in detail. (C) 2015 Elsevier B.V. All rights reserved.