Abstract
Experiments were conducted on an Al-5.5% Mg-2.2% Li-0.12% Zr alloy to investigate the feasibility of introducing an ultra-fine grain size using equal-channel angular (ECA) pressing and of retaining an ultra-fine grain size at elevated temperatures. It is shown that ECA pressing is capable of reducing the grain size from an initial value of ∼ 400 μm to a value of ∼ 1.2 μm. However, the microstructure after ECA pressing is heterogeneous, with many areas of equiaxed grains having high angle grain boundaries and some regions of subgrains with boundaries having low angles of misorientation. Unlike earlier experiments on Al-Mg binary alloys, it is demonstrated that the grain size of the Al-Mg-Li-Zr alloy is reasonably stable up to temperatures as high as ∼ 700 K because of the presence in the matrix of a fine dispersion of β′-Al3Zr precipitates. Microhardness data confirm the Hall-Petch relationship for grain sizes above ∼ 2 μm produced by annealing at temperatures above ∼ 673 K, but the Hall-Petch relationship breaks down at smaller grain sizes because of variations in the volume fraction of the δ′-Al3Li precipitates.
| Original language | English |
|---|---|
| Pages (from-to) | 4751-4757 |
| Number of pages | 7 |
| Journal | Acta Materialia |
| Volume | 45 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Jan 1 1997 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys
Cite this
Structural evolution and the Hall-Petch relationship in an Al-Mg-Li-Zr alloy with ultra-fine grain size. / Furukawa, Minoru; Iwahashi, Yoshinori; Horita, Zenji; Nemoto, Minoru; Tsenev, Nikolai K.; Valiev, Ruslan Z.; Langdon, Terence G.
In: Acta Materialia, Vol. 45, No. 11, 01.01.1997, p. 4751-4757.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Structural evolution and the Hall-Petch relationship in an Al-Mg-Li-Zr alloy with ultra-fine grain size
AU - Furukawa, Minoru
AU - Iwahashi, Yoshinori
AU - Horita, Zenji
AU - Nemoto, Minoru
AU - Tsenev, Nikolai K.
AU - Valiev, Ruslan Z.
AU - Langdon, Terence G.
PY - 1997/1/1
Y1 - 1997/1/1
N2 - Experiments were conducted on an Al-5.5% Mg-2.2% Li-0.12% Zr alloy to investigate the feasibility of introducing an ultra-fine grain size using equal-channel angular (ECA) pressing and of retaining an ultra-fine grain size at elevated temperatures. It is shown that ECA pressing is capable of reducing the grain size from an initial value of ∼ 400 μm to a value of ∼ 1.2 μm. However, the microstructure after ECA pressing is heterogeneous, with many areas of equiaxed grains having high angle grain boundaries and some regions of subgrains with boundaries having low angles of misorientation. Unlike earlier experiments on Al-Mg binary alloys, it is demonstrated that the grain size of the Al-Mg-Li-Zr alloy is reasonably stable up to temperatures as high as ∼ 700 K because of the presence in the matrix of a fine dispersion of β′-Al3Zr precipitates. Microhardness data confirm the Hall-Petch relationship for grain sizes above ∼ 2 μm produced by annealing at temperatures above ∼ 673 K, but the Hall-Petch relationship breaks down at smaller grain sizes because of variations in the volume fraction of the δ′-Al3Li precipitates.
AB - Experiments were conducted on an Al-5.5% Mg-2.2% Li-0.12% Zr alloy to investigate the feasibility of introducing an ultra-fine grain size using equal-channel angular (ECA) pressing and of retaining an ultra-fine grain size at elevated temperatures. It is shown that ECA pressing is capable of reducing the grain size from an initial value of ∼ 400 μm to a value of ∼ 1.2 μm. However, the microstructure after ECA pressing is heterogeneous, with many areas of equiaxed grains having high angle grain boundaries and some regions of subgrains with boundaries having low angles of misorientation. Unlike earlier experiments on Al-Mg binary alloys, it is demonstrated that the grain size of the Al-Mg-Li-Zr alloy is reasonably stable up to temperatures as high as ∼ 700 K because of the presence in the matrix of a fine dispersion of β′-Al3Zr precipitates. Microhardness data confirm the Hall-Petch relationship for grain sizes above ∼ 2 μm produced by annealing at temperatures above ∼ 673 K, but the Hall-Petch relationship breaks down at smaller grain sizes because of variations in the volume fraction of the δ′-Al3Li precipitates.
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UR - http://www.scopus.com/inward/citedby.url?scp=0031270180&partnerID=8YFLogxK
U2 - 10.1016/S1359-6454(97)00120-1
DO - 10.1016/S1359-6454(97)00120-1
M3 - Article
AN - SCOPUS:0031270180
VL - 45
SP - 4751
EP - 4757
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
IS - 11
ER -