J. Otubo, L. K. Kabayama, O. D. Rigo, E. M. Sashihara, Instituto Tecnologico de Aeronautica, S. J. dos Campos, Brazil
Earlier works showed that NiTi shape memory allow production by electron beam melting (EBM) is a viable process in which its main characteristic is the low contamination by impurities such as carbon and oxygen. Some difficulties arise when compared to conventional vacuum induction melting (VIM) process such as composition control and complex machine operation. This work will focus on the production of ever made large scale NiTi ingot (150mm in diameter) analyzing the operational problem, chemical composition control and its relation to microstructure and martensitic transformation temperatures.
Summary: This work presents the production of large scale (150 mm in diameter) NiTi ingot by EBM discussing operational problem, comparison to VIM process, the degree of contamination by carbon and oxygen and some other related aspects.
