Behavior of Hydrogen in Al-4%Mg Alloys during Heat Treatment

2007 ◽  
Vol 539-543 ◽  
pp. 305-310
Author(s):  
Hidetoshi Umeda ◽  
Goroh Itoh ◽  
Yoshinori Kato
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Hydrogen Content ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Mg Alloys ◽  
Annealing Atmosphere ◽  
Cast Slab ◽  
Fe Content ◽  
Al Mg Alloys

The effect of the annealing atmosphere, the annealing temperature etc. on the hydrogen behavior in several Al-4% Mg alloys during heat treatment, was investigated. The results have shown that the hydrogen content in the as-cast slab is uniform, while the hydrogen content in the slab tends to be higher near the surface than in the interior after annealing. Such a tendency becomes more marked when annealing time is prolonged and Si and Fe content is lowered. The condensation of hydrogen near the surface can be seen only when it is annealed in a wet atmosphere. When annealed in a dry atmosphere, the hydrogen content near the surface becomes lower than in the center of the specimen. The hydrogen in Al-Mg alloys tends to be released to outside intrinsically at temperatures around 400°C and above. It is revealed that oxide film formed on the surface prevents the hydrogen from being released to outside.

Effect of Heat Treatment Condition and Alloy Composition on Hydrogen Content in Al-Mg Alloys

2006 ◽  
Vol 519-521 ◽  
pp. 1895-1900
Author(s):  
Hidetoshi Umeda ◽  
Goroh Itoh ◽  
Yoshinori Kato
Keyword(s):  
Heat Treatment ◽  
Hydrogen Content ◽  
Heat Treatment Condition ◽  
Mg Alloys ◽  
Alloying Elements ◽  
Shielding Effect ◽  
Treatment Conditions ◽  
Atmosphere Temperature ◽  
Impurity Elements ◽  
Al Mg Alloys

The effect of heat treatment conditions such as atmosphere, temperature, annealing time and alloying elements on the hydrogen content in Al-Mg based alloys was investigated. The hydrogen content after annealing depends on the annealing atmospheres and alloying elements. When annealed in a wet atmosphere, the release of the hydrogen in the Al-Mg alloys to outside and the absorption of hydrogen from atmosphere into Al-Mg alloys are presumed to occur at the same time. The oxide layer on the surface is revealed to prevent the hydrogen from being released to outside. The spheroidal MgO particles can be seen on the surface of Al-Mg alloys after annealing at 550°C. The number of the MgO particles increases with increasing impurity elements such as Si and Fe, reducing the shielding effect against hydrogen permeration. Therefore, the condensation of hydrogen near the surface after annealing occurs more easily in an Al-Mg alloy of a high-purity than that of an ordinary purity.

Relationship of Microstructure and Mechanical Properties in Er-Containing Aluminum Alloy

2015 ◽  
Vol 1120-1121 ◽  
pp. 1109-1114
Author(s):  
Xin Lei ◽  
Hui Huang ◽  
S.P. Wen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Treatment Process ◽  
Mg Alloys ◽  
The Other ◽  
Heat Treatment Process ◽  
Comprehensive Performance ◽  
Relationship Of ◽  
Al Mg Alloys

This study investigated the mechanical properties and microstructures of Er-containing Al–Mg alloys. The research found that the H114-T sheet of Er-containing Al–Mg alloys showed a relative good comprehensive performance in mechanical properties. With the special rolling and heat treatment process, this H114-T sheet showed different morphology of microstructures with the other sheets in Er-containing Al–Mg alloys. Grains in H114-T sheet performed irregular shape polygon, a number of subgrains appeared in grains, the amount of dislocations in grains decreased. H114-T sheet possessed a lot of Copper texture, this may be one of important factors influenced the mechanical properties.

First Paper: The Effect of Heat Treatment on the Ductility of Alloy Steel Wires in a Cold Heading Process

1969 ◽  
Vol 184 (1) ◽  
pp. 875-884 ◽  
Author(s):  
P. F. Thomason
Keyword(s):  
Heat Treatment ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Steel Wire ◽  
Groove Depth ◽  
Air Cooling ◽  
Steel Wires ◽  
Fracture Crack ◽  
Different Types ◽  
Process Annealing

Longitudinal grooves of various depths ranging from 0.001 in to 0.011 in were machined on the cylindrical surface of steel slugs prior to carrying out an automatic two-stage transfer heading operation. The longitudinal grooves were used to estimate the ‘critical groove depth’, which was defined as the depth of longitudinal groove that contained a ductile fracture crack just on the point of ‘opening out’ at the end of the heading process, thus giving a measure of the ductility of the wire. A half-replicate of a two-level factorial experiment was carried out to assess the effects and interactions of annealing temperature, annealing time, cooling rate and ageing temperature on the ductility of four different types of 1/2 in diameter cold heading steel wire. The results show that certain types of steel wires have optimum ductility in the ‘as-received’, cold-drawn, state. Other types of steel are shown to respond favourably to process annealing treatments, in which case annealing at 700°C for 1 hour followed by air cooling should give optimum ductility. It is shown that there is no general correlation between decreasing hardness and increasing ductility for steel wire.

Study of double oxide film defect behaviour in liquid Al–Mg alloys

2013 ◽  
Vol 26 (6) ◽  
pp. 330-338 ◽  
Author(s):  
S. Amirinejhad ◽  
R. Raiszadeh ◽  
H. Doostmohammadi
Keyword(s):  
Oxide Film ◽  
Mg Alloys ◽  
Double Oxide ◽  
Film Defect ◽  
Al Mg Alloys

Effects of Heat Treatment on Growth of BaSi2 Film on Si(111) Substrates

2010 ◽  
Vol 663-665 ◽  
pp. 1273-1276
Author(s):  
Zi Yi Yang ◽  
Zheng Tong Hao ◽  
Quan Xie
Keyword(s):  
Heat Treatment ◽  
Magnetron Sputtering ◽  
Growth Mechanism ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Morphological Features ◽  
Subsequent Annealing

Semiconducting orthorhombic BaSi2 films were synthesized on Si(111) substrates using magnetron sputtering (MS) and subsequent annealing by interdiffusion between the deposited Ba film and Si(111) substrate. The structural and morphological features of the result films are analysed. The growth mechanism and the evolution of the silicides are discussed. The effects of annealing temperature and annealing time on the growth of the BaSi2 film are studied.

scholarly journals Effects of Mg Content on Hydrogen Content and Melt Quality of Al-Mg Alloys

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1235 ◽  
Author(s):  
Jang ◽  
Kang ◽  
Yoon ◽  
Lee ◽  
Jeon ◽  
...  
Keyword(s):  
Hydrogen Content ◽  
Theoretical Calculations ◽  
Mg Alloys ◽  
Melt Temperature ◽  
Temperature Oxidation ◽  
Dissolved Hydrogen ◽  
Mg Content ◽  
Porosity Measurements ◽  
Al Mg Alloys

In Al-Mg alloys with Mg content 0 ≤ XMg ≤ 6 wt. %, the effects of XMg on dissolved hydrogen content ([H]) and melt quality were investigated. [H] was measured using the Closed-Loop Recirculation method, and the melt quality was quantified using the density index (DI), bifilm index (BI), and porosity measurement. [H] in the molten alloys increased with increasing XMg and melt temperature TMelt; these trends agree with theoretical calculations for hydrogen solubility. The tendency of melt quality vs XMg was similar in DI, BI, and porosity measurements, and the poorest melt quality was observed in the Al-4Mg alloy that had XMg = 4 wt. %, whereas the highest [H] was obtained in the Al-6Mg alloy melt that had XMg = 6 wt. % Mg. During thermogravimetric/differential thermal analysis, rapid oxidation occurred in the Al-4Mg alloy melt during the holding time between 45 and 60 min at 800 °C., i.e., just before the molten metal was cast. The inferior melt quality of Al-4Mg alloy may have been caused by high-temperature oxidation.

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