中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 20 No. 5 May 2010 |
directionally solidified nickel-based superalloy
（1. State Key Laboratory for Corrosion and Protection, Institute of Metal Research,
Chinese Academy of Sciences, Shenyang 110016, China;
2. School of Science, Northeastern University, Shenyang 110004, China）
Abstract:An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark deposition. Epitaxial morphologies of the coating and its microstructural characteristics were investigated by means of SEM, XRD and TEM etc. It is observed that the fine column-like dendrites originated from the γ′-particles or γ′-clusters of the DS substrate and are un-continuously coarsened. The β-phase particles precipitate and grow eutectically with the γ-phase. The orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.
Key words: electro-spark deposition; epitaxial growth; MCrAlY alloy; Ni-base superalloy
