Structure and Properties of Melt Grown Nb-Nb2C Composites.

Abstract : The report consists of two preprints. One preprint describes a process for growing eutectic and hypereutectic Nb-Nb2C composites by an electron beam floating zone freezing technique. The structure is characterized as a function of carbon content and growth rate. The conditions for interface stability in the Nb-Nb2C system are compared to present theoretical models. The second preprint discusses sources of banding in composite growth and pays particular attention to banding that results from nonuniformity in the feed rod. This mechanism is important in composite growth techniques employing zone melting and may be avoided by zone levelling prior to composite growth. (Author)