Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Al45Cr7”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

2 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Al45Cr7 by Materials Project

Al45Cr7 is Bergman Structure: Mg32(Al,Zn)49 Bergman-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded to twelve Al atoms to form corner-sharing CrAl12 cuboctahedra. There are a spread of Cr–Al bond distances ranging from 2.56–2.89 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form distorted CrAl12 cuboctahedra that share a cornercorner with one CrAl12 cuboctahedra, a cornercorner with one AlAl8Cr4 cuboctahedra, and a faceface with one AlAl9Cr3 cuboctahedra. There are a spread of Cr–Al bond distances ranging from 2.47–2.91 Å. In the third Cr site, Cr is bonded in a 12-coordinate geometry to one Cr and eleven Al atoms. The Cr–Cr bond length is 2.64 Å. There are a spread of Cr–Al bond distances ranging from 2.47–2.79 Å. There are eighteen inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Cr and eight Al atoms to form AlAl8Cr4 cuboctahedra that share corners with two equivalent CrAl12 cuboctahedra and faces with two equivalent AlAl9Cr3 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.57–2.70 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.79–2.88 Å. In the third Al site, Al is bonded in a 11-coordinate geometry to three Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.66–3.03 Å. In the fourth Al site, Al is bonded to three Cr and nine Al atoms to form distorted AlAl9Cr3 cuboctahedra that share a cornercorner with one AlAl9Cr3 cuboctahedra, a faceface with one CrAl12 cuboctahedra, and a faceface with one AlAl8Cr4 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.73–2.84 Å. In the fifth Al site, Al is bonded in a 11-coordinate geometry to two equivalent Cr and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–2.84 Å. In the sixth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–2.89 Å. In the seventh Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.92 Å. In the eighth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–3.00 Å. In the ninth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.66–2.92 Å. In the tenth Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–2.96 Å. In the eleventh Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–2.93 Å. In the twelfth Al site, Al is bonded in a 2-coordinate geometry to two Cr and ten Al atoms. There are one shorter (2.85 Å) and one longer (2.88 Å) Al–Al bond lengths. In the thirteenth Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.80–2.98 Å. In the fourteenth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and eleven Al atoms. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the fifteenth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and eleven Al atoms. Both Al–Cr bond lengths are 2.77 Å. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the sixteenth Al site, Al is bonded in a 12-coordinate geometry to one Cr and ten Al atoms. There are one shorter (2.76 Å) and three longer (2.92 Å) Al–Al bond lengths. In the seventeenth Al site, Al is bonded in a 12-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the eighteenth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. The Al–Al bond length is 2.83 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Microstructural Assessment of a Multiple-Intermetallic-Strengthened Aluminum Alloy Produced from Gas-Atomized Powder by Hot Extrusion and Friction Extrusion

An aluminum (Al) matrix with various transition metal (TM) additions is an effective alloying approach for developing high-specific-strength materials for use at elevated temperatures. Conventional fabrication processes such as casting or fusion-related methods are not capable of producing Al–TM alloys in bulk form. Solid phase processing techniques, such as extrusion, have been shown to maintain the microstructure of Al–TM alloys. In this study, extrusions are fabricated from gas-atomized aluminum powders (≈100–400 µm) that contain 12.4 wt % TM additives and an Al-based matrix reinforced by various Al–Fe–Cr–Ti intermetallic compounds (IMCs). Two different extrusion techniques, conventional hot extrusion and friction extrusion, are compared using fabricating rods. During extrusion, the strengthening IMC phases were extensively refined as a result of severe plastic deformation. Furthermore, the quasicrystal approximant IMC phase (70.4 wt % Al, 20.4 wt % Fe, 8.7 wt % Cr, 0.6 wt % Ti) observed in the powder precursor is replaced by new IMC phases such as Al3.2Fe and Al45Cr7-type IMCs. The Al3Ti-type IMC phase is partially dissolved into the Al matrix during extrusion. The combination of linear and rotational shear in the friction extrusion process caused severe deformation in the powders, which allowed for a higher extrusion ratio, eliminated linear voids, and resulted in higher ductility while maintaining strength comparable to that resulting from hot extrusion. Results from equilibrium thermodynamic calculations show that the strengthening IMC phases are stable at elevated temperatures (up to ≈ 600 °C), thus enhancing the high-temperature strength of the extrudates.

36 MATERIALS SCIENCE↗