Rapid Solidification Processing of High Temperature and Reactive Alloys

An experimental study has been undertaken to develop the technology for producing high temperature and reactive metal alloys through rapid solidification processing (RSP). An empirical approach has been used to develop these processes. Several unique configurations of melting and quenching have been evaluated. Induction, DC-arc and plasma have been considered for initial melting of these alloys. Centrifugal atomization and melt-spinning have been evaluated as means of rapid quenching. Several alloys of Ti and Nb were selected because of the current interest in the aerospace community in their development. Rare-earth oxide dispersions were formed in Ti alloys with Al content ranging from 0 to 50 at.%. Several intermetallic alloys were studied, such as Ti$\sb3$Al, TiAl, Ti$\sb5$Si$\sb3$, TiB$\sb2$ and TiC. The effects of RSP on Nb alloys with additions of Al and Si were also studied. Standard chemical analysis was used to evaluate the chemical uniformity and purity of the alloys in the RSP condition. These analyses were used to evaluate the effectiveness of the process involved. Microscopic analysis was performed on each alloy through the use of transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy to determine the effects of RSP on microstructure. Powder and ribbon produced through RSP were analyzed in the assolidified state and following thermal treatments to determine the extent of undercooling and microstructural modifications.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Sears, James William

Contributors dc:contributor

• Fraser, Hamish L.

• Engineering, Mechanical
• Engineering, Metallurgy
• Engineering, Materials Science

Identifier

(UMI)AAI8823245

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70154