Microstructural and Mechanical Characterization of Directionally Solidified Conventional and Nb-Modified Mar-M247 Superalloy - Costa, A. M. S.; Lopes, E.S.N; Contieri, Rodrigo J; Caram, R; Baldan, Renato; Fuchs, G. E.; Nunes, Carlos Angelo (Journal of materials engineering and performance, 2019)