Contributions of Light Microscopy to Contemporary Materials Characterization: The New Directional Solidification

Abstract

In this article, we illustrate novel, columnar precipitate architectures in Co-base and Ni-base superalloys, and Cu components, directionally fabricated by electron beam melting; using light microscopy (LM). These microstructural architectures and related microstructural features are characteristic of a new directional solidification phenomenon created by selective melting of precursor powder layers, forming 3-dimensional (3D) products which result by additive manufacturing. Comprehensive, micron-scale observations rendered in 3D metallography are supplemented by transmission electron microscopy and scanning electron microscopy to provide a structural and microstructural overview. These observations illustrate the continuing importance of LM in contemporary materials characterization applied to advanced metals technologies. © 2012 Springer Science+Business Media, LLC and ASM International.