Intermetallic Growth and Interdiffusion in the Mg-Nd System
Abstract
Magnesium alloys with rare earth additions have exhibited high strength at room and elevated temperatures and good creep resistance largely due to their age hardenability. This study utilizes solid diffusion couples of pure magnesium and neodymium to observe the formation and growth of intermetallic phases and the interdiffusion behavior of the system. Diffusion anneals were carried out between 400 and 500 C. The resulting microstructures were examined with a scanning electron microscope and concentration profiles across the interdiffusion zone were determined via electron microprobe analysis. Two intermetallic phases were identified, Mg41Nd5 and Mg3Nd5. The MgNd phase was not observed in any of the diffusion couples. Parabolic growth constants and activation energies for growth were calculated for each phase. The Mg41Nd5 phase had higher growth constants. Activation energies for the growth of the intermetallic phases were calculated to be 79 kJ/mol for the Mg41Nd5 phase and 120 kJ/mol for the Mg3Nd phase.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2012
- Accession Number
- ADA566009
Entities
People
- Katrina Bermudez
- Sarah Brennan
- Yongho Sohn
Organizations
- United States Army Research Laboratory