scholarly journals Effects of pre-aging at elevated temperature and natural aging on the bake hardenability of Al–Mg–Si alloy

2009 ◽  
Vol 59 (5) ◽  
pp. 248-253 ◽  
Author(s):  
Hidenori Hatta ◽  
Shinichi Matsuda ◽  
Hiroki Tanaka ◽  
Hideo Yoshida
Keyword(s):  
Elevated Temperature ◽  
Natural Aging ◽  
Bake Hardenability

Study on the Formability of Aluminium Alloy Sheets at Room and Elevated Temperatures

2016 ◽  
Vol 877 ◽  
pp. 393-399
Author(s):  
Jia Zhou ◽  
Jun Ping Zhang ◽  
Ming Tu Ma
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Elevated Temperature ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Elevated Temperatures ◽  
Hot Stamping ◽  
Natural Aging ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet

This paper presents the main achievements of a research project aimed at investigating the applicability of the hot stamping technology to non heat treatable aluminium alloys of the 5052 H32 and heat treatable aluminium alloys of the 6016 T4P after six months natural aging. The formability and mechanical properties of 5052 H32 and 6016 T4P aluminum alloy sheets after six months natural aging under different temperature conditions were studied, the processing characteristics and potential of the two aluminium alloy at room and elevated temperature were investigated. The results indicated that the 6016 aluminum alloy sheet exhibit better mechanical properties at room temperature. 5052 H32 aluminum alloy sheet shows better formability at elevated temperature, and it has higher potential to increase formability by raising the temperature.

scholarly journals Effects of Mg, Si contents and natural aging conditions on the bake hardenability of Al-Mg-Si alloys

2004 ◽  
Vol 54 (10) ◽  
pp. 412-417 ◽  
Author(s):  
Hidenori HATTA ◽  
Hiroki TANAKA ◽  
Shinichi MATSUDA ◽  
Hideo YOSHIDA
Keyword(s):  
Natural Aging ◽  
Aging Conditions ◽  
Bake Hardenability

Effects of Cu or Li Addition and Multi-Step Aging Conditions on the Bake-Hardenability of an Al-Mg-Si Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1152-1156 ◽  
Author(s):  
Yuki Koshino ◽  
Shoichi Hirosawa ◽  
Yasuhiro Aruga ◽  
Hisao Shishido ◽  
Katsushi Matsumoto
Keyword(s):  
Fuel Consumption ◽  
Volume Fraction ◽  
Natural Aging ◽  
Aging Treatment ◽  
Hardness Test ◽  
Specific Strength ◽  
Alternative Material ◽  
Aging Conditions ◽  
Microalloying Elements ◽  
Bake Hardenability

In recent years, automobiles with lower fuel consumption are required because the exhaust fume is severely regulated. The weight-saving is quite effective to realize such low fuel consumption, and therefore aluminum alloy becomes attractive as an alternative material of steels due to its high specific strength. 6XXX series Al-Mg-Si alloys exhibit good bake-hardenability during paint-bake treatment in the automobile manufacturing process, but to reduce further environmental impact, the paint-baking temperature is supposed to be lowered than the present temperature of about 443K. In this study, it was aimed to investigate the attained hardness after paint-bake treatment at various temperatures of 408-443K for an Al-0.55wt%Mg-0.90wt%Si alloy with/without microalloying elements of Cu and Li. The effects of multi-step aging conditions; e.g. pre-aging, natural aging and paint-bake treatments, were also investigated through Vickers hardness test, TEM observation and DSC analysis. From the obtained experimental results, it was clarified that the addition of Cu or Li to the Al-Mg-Si alloy increases the attained hardness even at a paint-baking temperature of 408K due to the increased volume fraction of precipitates. Furthermore, pre-aging treatment at 373K for 18ks was also effective in suppressing the increase in hardness during natural aging, resulting in the highest attained hardness among the investigated multi-step aging conditions; i.e. HV100 in the Li-added alloy paint-baked at 408K.

Evidence for a shear mechanism for the precipitation of γ-zirconium hydride in zirconium

1978 ◽  
Vol 36 (1) ◽  
pp. 658-659
Author(s):  
G.J.C. Carpenter
Keyword(s):  
Elevated Temperature ◽  
Strain Field ◽  
Zirconium Hydride ◽  
Zirconium Atom ◽  
Atom Diffusion ◽  
Solvus Temperature ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
The Face

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

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