Shock consolidation of mechanically alloyed amorphous Ti-Si powders
- Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering
Mechanical alloying was used to synthesize amorphous 5Ti-3Si atomic ratio powders in a SPEX mill under Ar atmosphere. X-ray diffraction analysis revealed formation of a single-phase amorphous compound after about 24 hours of milling. High-resolution transmission electron microscopy (TEM) showed that the milled powder still contained nanocrystallites of Ti and Si among regions of generally amorphous compound. The mechanically alloyed amorphous powder was shock consolidated, using a plate impact assembly, to produce bulk compacts. The compaction resulted in a significant amount of crystallization, forming 30- to 40-nm crystals of TiSi{sub 2} and Ti{sub 5}Si{sub 3} intermetallic compounds. The compacts were subsequently annealed above the crystallization temperature, measured to be {approximately}640 C using differential thermal analysis. The compacts annealed at 800 C for 1 hour showed only limited grain growth to {approximately}50-nm crystallite size. Microhardness of the shocked amorphous alloy compacts was {approximately}1,100 KHN, which increased to {approximately}1,250 KHN upon subsequent annealing, with the formation of a more homogeneous nanocrystalline microstructure.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 131437
- Journal Information:
- Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 10 Vol. 26; ISSN 0360-2133; ISSN MTTABN
- Country of Publication:
- United States
- Language:
- English
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