|
Ductile Thin Foils of NiAl Pages: 14 Published: Jan 2001
Download this paper for $25
PDF (408K)
View License Agreement Source: STP1413-EB Abstract NiAl thin foils with 315 to 357 m thickness were successfully fabricated by cold rolling. X-ray pole figures showed the formation of {110} rolling textures with various rolling directions in the foils cold rolled over 83% reduction. The deformation microstructure consists of fine slip traces and coarse and wavy shear bands. Banded deformation structure was observed in some foils. In the foils cold rolled to 83% reduction, the Vickers hardness number reached over 600 and the ultimate tensile strength over 1.7 GPa, irrespective of rolling texture and deformation microstructure. The cold rolled foils showed no tensile elongation, but it was possible to bend the foils. The foils recrystallized at temperatures over 1273 K had some tensile ductility (3.0 to 14.6%), though the polycrystalline NiAl is known to be brittle due to severe grain boundary fracture. Electron backscatter diffraction measurements revealed that the large amount of total grain boundary area consists of low angle (LAB) and 3 coincidence lattice boundaries. This large fraction is probably a chief cause of the observed ductility.
| ||
