scholarly journals The Effect of Cooling Rate after Homogenization on the Microstructure and Properties of 2017a Alloy Billets for Extrusion with Solution Heat Treatment on the Press

2016 ◽  
Vol 61 (3) ◽  
pp. 1663-1670
Author(s):  
A. Woźnicki ◽  
D. Leśniak ◽  
G. Włoch ◽  
P. Pałka ◽  
B. Leszczyńska-Madej ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Solution Heat Treatment ◽  
Rapid Heating ◽  
The Press ◽  
Large Particles ◽  
Rapid Dissolution ◽  
Alloy Microstructure ◽  
Fast Dissolution ◽  
Short Time

AbstractThe influence of cooling rate after homogenization on the 2017A alloy microstructure was analysed. The capability of the θ (Al2Cu) particles, precipitated during various homogenization coolings, for rapid dissolution was estimated. For this purpose, the DSC test was used to determine the effect of the cooling rate after homogenization on the course of melting during a rapid heating. Moreover, the samples after solution heat treatment (with short time annealing) and ageing, were subjected to the microstructure investigations and the microhardness of grains interiors measurements. It was found that cooling after homogenization at 160 °C/h is sufficient for precipitation of fine θ phase particles, which dissolve during the subsequent rapid heating. The cooling at 40 °C/h, causes the precipitation of θ phase in the form of large particles, incapable of further fast dissolution.

scholarly journals The Effect Of Homogenization Conditions On The Structure And Properties Of 6082 Alloy Billets

2015 ◽  
Vol 60 (3) ◽  
pp. 1763-1772 ◽  
Author(s):  
A. Woźnicki ◽  
D. Leśniak ◽  
G. Włoch ◽  
B. Leszczyńska-Madej ◽  
A. Wojtyna
Keyword(s):  
Solution Heat Treatment ◽  
Rapid Heating ◽  
Structure And Properties ◽  
Alloying Additions ◽  
Large Particles ◽  
Rapid Dissolution ◽  
Fast Dissolution ◽  
Short Annealing ◽  
Si Content ◽  
Research Stage

Abstract The paper presents the results of laboratory homogenization investigations of the 6082 grade alloys, differing in Mg and Si content. At the first stage, the microstructure of alloys was analysed after homogenization finished with water quenching. SEM/EDS investigations and DSC tests were applied to evaluate the dissolution of the Mg2Si particles and concentration of the main alloying additions in the grains interiors, depending on soaking conditions. In the case of alloy with lower Mg and Si content, homogenization the temperature of 535ºC for 8h is sufficient for significant Mg2Si particles dissolution. For the alloy with higher Mg and Si content, after homogenization the temperature of 550ºC for 8h, the amount of undissolved Mg2Si particles decreases visibly, compared to homogenization at 535ºC for 8h. However, an unfavourable tendency of dispersoids growth is observed and these soaking conditions are not found to be recommended. At the second research stage, the influence of homogenization cooling rate on the size and distribution of the Mg2Si particles observed in the alloys microstructure was analysed. The ability of the Mg2Si particles, precipitated during various homogenization coolings, to rapid dissolution was estimated. For this purpose, the hardness after solution heat treatment with short annealing and ageing was determined and the DSC tests were performed. It was found, that cooling after homogenization at 315ºC/h is sufficient for precipitation of fine Mg2Si particles, which dissolve during subsequent rapid heating. Cooling at 40ºC/h, causes precipitation of Mg2Si phase in the form of large particles, unable for further fast dissolution.

Effects of cooling rate on solution heat treatment of as-cast A356 alloy

2015 ◽  
Vol 25 (10) ◽  
pp. 3189-3196 ◽  
Author(s):  
Chang-lin YANG ◽  
Yuan-bing LI ◽  
Bo DANG ◽  
He-bin LÜ ◽  
Feng LIU
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Solution Heat Treatment ◽  
A356 Alloy

The Effect of Solution Time on the Microstructure of A356.2 Aluminum Alloy Provided by Rheocasting and Squeeze Casting

2022 ◽  
Vol 327 ◽  
pp. 189-196
Author(s):  
Le Cheng ◽  
Hong Xing Lu ◽  
Min Luo ◽  
Xing Gang Li ◽  
Wan Peng Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Production Efficiency ◽  
Treatment Process ◽  
Squeeze Casting ◽  
Solution Process ◽  
Solution Treatment ◽  
Solution Time ◽  
Conventional Solution ◽  
Short Time

The evolution of the microstructure of A356.2 alloys prepared by the rheocasting and squeeze casting during solution heat treatment was investigated. In contrast with the conventional solution heat treatment process (3 hours at 540oC), a short time solution treatment process (less than 1 hour at 540oC) is applied in this paper. The results show that the rheocastings require a shorter solution time than the squeeze-castings to obtain spheroidized Si particles. After solution for 10 min, the X-ray diffraction inspection results show that the Mg2Si phase completely is dissolved in both rheocastings and squeeze-castings. However, a small amount of Mg2Si is found at the edge of the Si particle by scanning electron microscope observation. After solution for more than 20 min, the Mg2Si phase is completely dissolved. Fe-rich phases, including AlSiFeMg and AlFeSi, exist throughout the solution process. The developed T6 heat treatment with a short solution time can effectively improve production efficiency and decrease process cost for the rheocasting process. Key words: A356.2 alloy, microstructure, short solution time, rheocasting, squeeze casting

Effect of Low Cu Addition and Thermo-Mechanical History on Precipitation in Al-Mg-Si Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 1014-1019 ◽  
Author(s):  
Takeshi Saito ◽  
Calin D. Marioara ◽  
Jostein Røyset ◽  
Randi Holmestad
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Solution Heat Treatment ◽  
Precipitation Hardening ◽  
Peak Hardness ◽  
Isothermal Heat Treatment ◽  
Slow Cooling ◽  
Transmission Electron ◽  
Material Hardness ◽  
Initial Hardness

The effect of cooling rate after solution heat treatment and its combination with 1% pre-deformation on precipitation hardening in two Al-Mg-Si alloys is investigated by transmission electron microscopy (TEM), and related to material hardness. Two alloys have been used, one Cu-free and the other with low Cu additions (~0.1 wt%), both having the same amounts of other solutes. A double peak hardness evolution during an isothermal heat treatment was observed with slow cooling after solution heat treatment. This effect was less pronounced in the Cu-added alloy. The 1% pre-deformation also made this effect less pronounced, but it led to faster initial hardness evolution and delayed over-aging. Maximum hardness was not influenced by cooling rate and the pre-deformation. Hardness was directly related to precipitate number densities.

Softening of High-Strength Steel for Laser Assisted Clinching

2014 ◽  
Vol 966-967 ◽  
pp. 617-627 ◽  
Author(s):  
Julia Osten ◽  
Paul Söllig ◽  
Michael Reich ◽  
Jan Kalich ◽  
Uwe Füssel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Laser Heating ◽  
High Strength Steels ◽  
High Strength ◽  
Mechanical Analysis ◽  
Hardened Steel ◽  
The Press ◽  
Short Time ◽  
First Time

The conventional clinching of steels is currently limited to tensile strength less than 800 N/mm2 and to elongation at fracture more than 14 %. To realise the clinching of high-strength steels, the sheet can be heated locally at the joint, to improve ductility. Thereby the material characteristics outside the joint should be maintained. This could be achieved by means of short-time laser heating. The short-time tempering behaviour of press hardened steel 22MnB5 has been analysed. The mechanical properties during a short-time heat treatment were investigated by thermo-mechanical analysis in a deformation dilatometer. Thereby laser-assisted clinching shall be established and an efficient form-closed and force-closed connection shall be produced. As a result, the press hardened steel 22MnB5 could be clinched by laser assistance for the very first time.

Linear Friction Welding of Ti-6Al-4V Alloy: Microstructure Characterization

2008 ◽  
Vol 580-582 ◽  
pp. 405-408 ◽  
Author(s):  
Tie Jun Ma ◽  
Wen Ya Li ◽  
Q.Z. Xu ◽  
Y. Zhang ◽  
Jing Long Li ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Friction Welding ◽  
Rapid Heating ◽  
Linear Friction Welding ◽  
Heating And Cooling ◽  
Linear Friction ◽  
Fast Cooling ◽  
Alloy Microstructure ◽  
Weld Edge ◽  
Martensite Structure

Ti-6Al-4V was successfully jointed by linear friction welding (LFW). A sound weld of thickness of 65-115 $m was obtained under the present conditions. The weld consisted of the superfine α+β structure, which is associated with the rapid heating and cooling processes involved in LFW. The thermomechanically affected zone (TMAZ) was limited and comprised of the severely deformed α and β grains. In the flash, a gradual microstructure was formed from the weld edge to the flash edge. A martensite structure (α’) was formed besides the acicular α+β in the flash edge owing to the fast cooling rate.

scholarly journals Effects of Rapid Preheating and Solution Heat Treatment on Mechanical Properties of AA2618 Forged Samples

2012 ◽  
pp. 177-180
Author(s):  
A. Chennakesava Reddy
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Solution Heat Treatment ◽  
Mechanical Characteristics ◽  
Rapid Heating ◽  
Radiation Heating ◽  
Rapid Radiation

The microstructural and mechanical characteristics of rapid radiation heating and convection gas-fired heating on AA2618 forged samples have been studied. The rapid heating obtains refinement in grain size. The mechanical properties are greater in the AA2618 samples of rapid radiation heating.

Extrusion of AlCuMg Alloys with Simultaneous Solution Heat Treatment

2012 ◽  
Vol 57 (1) ◽  
pp. 19-31 ◽  
Author(s):  
D. Leśniak ◽  
A. Woźnicki
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Solution Heat Treatment ◽  
Fine Particles ◽  
High Strength ◽  
Extrusion Force ◽  
Simultaneous Solution ◽  
The Press ◽  
Temperature Homogenization

Extrusion of AlCuMg Alloys with Simultaneous Solution Heat Treatment In the work, the experiments on extrusion of high-strength aluminium alloys (2014 and 2024) with solution heat treatment on the press were performed. The experimental study describes extrudates microstructure and mechanical properties in dependence on alloy chemical composition, mode of homogenization treatment and temperature-speed extrusion conditions. The optical microscopy and SEM/EDS characterization were supported by DSC analysis, enabling to determine the solidus temperatures of the alloys. The investigations revealed that minimal contents of the main alloy additions (Cu, Mg), high-temperature homogenization and increased extrusion temperatures contributed to achieving high solutioning ratio of the alloys, guarantying improved mechanical properties of the extrudates. The high-temperature homogenization allowed achieving uniform microstructure of ingots with fine particles of intermetallic phases. The significant increase in solidus temperatures of the homogenized alloys enabled more effective solutioning on the run-out table. The maximal permissible metal exit speed was increased and the extrusion force was reduced in comparison to the conventional extrusion technology. The proposed solutions will allow for industrial producing AlCuMg extrudates of improved mechanical properties in the shortened technological cycle with heat treatment on the press.

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