Precipitation Behavior of Mg–Al–Sn–Zn–(Na) Alloy

Author(s):  
Su Mi Jo ◽  
Yohan Go ◽  
Bong Sun You ◽  
Young Min Kim
Author(s):  
J. E. O'Neal ◽  
K. K. Sankaran

Al-Li-Cu alloys combine high specific strength and high specific modulus and are potential candidates for aircraft structural applications. As part of an effort to optimize Al-Li-Cu alloys for specific applications, precipitation in these alloys was studied for a range of compositions, and the mechanical behavior was correlated with the microstructures.Alloys with nominal compositions of Al-4Cu-2Li-0.2Zr, Al-2.5Cu-2.5Li-0.2Zr, and Al-l.5Cu-2.5Li-0.5Mn were argon-atomized into powder at solidification rates ≈ 103°C/s. Powders were consolidated into bar stock by vacuum pressing and extruding at 400°C. Alloy specimens were solution annealed at 530°C and aged at temperatures up to 250°C, and the resultant precipitation was studied by transmission electron microscopy (TEM).The low-temperature (≲100°C) precipitation behavior of the Al-4Cu-2Li-0.2Zr alloy is a combination of the separate precipitation behaviors of Al-Cu and Al-Li alloys. The age-hardening behavior at these temperatures is characteristic of Guinier-Preston (GP) zone formation, with additional strengthening resulting from the coherent precipitation of δ’ (Al3Li, Ll2 structure), the presence of which is revealed by the selected-area diffraction pattern (SADP) shown in Figure la.


Author(s):  
M.J. Witcomb ◽  
U. Dahmen ◽  
K.H. Westmacott

Cu-Cr age-hardening alloys are of interest as a model system for the investigation of fcc/bcc interface structures. Several past studies have investigated the morphology and interface structure of Cr precipitates in a Cu matrix (1-3) and good success has been achieved in understanding the crystallography and strain contrast of small needle-shaped precipitates. The present study investigates the effect of small amounts of phosphorous on the precipitation behavior of Cu-Cr alloys.The same Cu-0.3% Cr alloy as was used in earlier work was rolled to a thickness of 150 μm, solution treated in vacuum at 1050°C for 1h followed by quenching and annealing for various times at 820 and 863°C.Two laths and their corresponding diffraction patterns in an alloy aged 2h at 820°C are shown in correct relative orientation in Fig. 1. To within the limit of accuracy of the diffraction patterns the orientation relationship was that of Kurdjumov-Sachs (KS), i.e. parallel close-packed planes and directions.


2004 ◽  
Vol 95 (1) ◽  
pp. 57-59 ◽  
Author(s):  
W. Mao ◽  
H. Ren ◽  
Y. Yu

JOM ◽  
2021 ◽  
Vol 73 (2) ◽  
pp. 668-678
Author(s):  
Hebin Wang ◽  
Da Hong ◽  
Longgang Hou ◽  
Ping Ou ◽  
Li Shen ◽  
...  

2021 ◽  
Vol 68 ◽  
pp. 716-727
Author(s):  
Jiang Yang ◽  
Honggang Dong ◽  
Yueqing Xia ◽  
Peng Li ◽  
Wei Wu ◽  
...  

Materialia ◽  
2021 ◽  
Vol 15 ◽  
pp. 101035
Author(s):  
Ling Wang ◽  
Kinga A. Unocic ◽  
Peter F. Tortorelli ◽  
Michael Santella ◽  
Xiang  (Frank) Chen

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