Influence of the nature of an electric field applied during the solution heat treatment of the Al-Mg-Si-Cu Alloy AA6111 on subsequent natural aging

Author(s):  
Hans Conrad ◽  
Jun Wang
2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Ronan Miller Vieira ◽  
Gianni Ferreira Alves Moreira ◽  
André Itman Filho ◽  
Estéfano Aparecido Vieira

This work has focused on the development of a new aluminum alloy containing 4.8 wt% of Cu alloy obtained from recycled aluminium cans designed for thixoforming process. After the step of melting and solidification of the alloy in a metallic permanent mold, samples were solution heat treated at 525°C for times ranging from 2 h to 48 h, quenched in water and followed by natural aging. Results have shown the evolution of hardness so from them solubilization solution heat treatment was chosen for 24 h. The best condition for aging was 190°C during 3 h. With this data pieces were thixoforged at 580°C and 615°C corresponding, respectively, to solid fraction (fs) of 0.8 and 0.6. The optimized T6 temper was applied and tensile tests were performed. The mechanical properties obtained are compatible with those obtained for consolidated alloys processed in semisolid state (SS) and after T6 temper hardness increases from 95 HB to 122 HB and the best results were a tensile strength of 324 MPa ± 10 MPa, yield strength of 257 MPa ± 18 MPa, and an elongation of 7.1%  ±  1%. For alloys designed for thixoforming process, these results are in accordance with what was expected whereas globular microstructure, high ductility, and good performance under cyclic conditions are desirable.


2013 ◽  
Vol 765 ◽  
pp. 496-500 ◽  
Author(s):  
Dawid Kapinos ◽  
Marcin Szymanek ◽  
Bogusław Augustyn ◽  
Maciej Gawlik

The article presents the change in mechanical properties of AlZn9Mg2.5Cu1.8 alloy resulting from the process of solution heat treatment and aging. The heat treatment was performed on a unique UMSA (Universal Metallurgical Simulator and Analyzer) device. The aim of the study was to determine optimum heat treatment parameters for the tested alloy of ultrafine grain structure obtained by Rapid Solidification (RS). To achieve this purpose, heat treatment to the T4 and T6 condition was carried out. The solution heat treatment was carried out at a constant temperature of 460 °C for 2 hours, while the time - temperature parameters of the aging process varied. The treatment undertaken resulted in improved mechanical properties.


2019 ◽  
Vol 25 (3) ◽  
pp. 281-285
Author(s):  
Dhanashekar MANICKAM ◽  
Senthil Kumar VELUKKUDI SANTHANAM

Aluminium alloys are subjected to heat treatment to increase the strength and corrosion properties. This paper aims to study the effect of heat treatment on the compression behaviour of A356 alloy under quasi static condition and barreling effect. The various heat treatments are: (i) solution heat treatment of 1 h at 540 °C + natural aging 0 h + artificial aging at 180 °C up to 5.5 h, (ii) solution heat treatment of 3 h at 540 °C + natural aging for 20 h + artificial aging at 180 °C up to 5.5 h, and (iii) solution heat treatment of 6 h at 540 °C + natural aging for 20 h + artificial aging at 180 °C up to 5.5 h. Specially to understand the influence of artificial aging at every 0.5 h up to 5.5 h, the specimens were heat treated. From the results, solutionizing for 1 hr have a better compression strength irrespective of the artificial aging. Natural aging had decreased the ductility but increased the strength property. Artificial aging had a significant effect on the compressive strength and peak strength were obtained at 4 h irrespective of solutionizing heat treatment. Compressive strength increased by 33 % for 1 h of solutionizing and 4 h of artificial aged specimen when compared to non-heat treated alloy. Two mathematical relations discussed in literature were used for calculating the radius of the barreled surface followed by validation. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20442


2013 ◽  
Vol 749 ◽  
pp. 54-60
Author(s):  
Yao Qiang Gan ◽  
Lei Lu ◽  
Da Tong Zhang ◽  
Wei Wen Zhang ◽  
Yuan Yuan Li

A high strength Al-Cu-Mg alloy was prepared by squeeze casting. The effects of squeeze casting and heat treatment on the microstructures and mechanical properties of the alloy were studied. It was found that squeeze casting refined the microstructure and reduced the micro-segregation markedly, and also accelerated the diffusion process of solute atoms during solution heat treatment. Tensile strength and elongation of squeeze casting alloy were much higher than those of gravity casting alloy under both the as-cast and heat-treated conditions. In addition, the Al-Cu-Mg alloy prepared by squeeze casting showed good natural aging response, and the naturally-aged alloy possessed a slightly lower tensile strength but better elongation compared to full artificial aging. After solution heat treatment at 495 for 9h and further natural aging for 48h or artificial aging at 190 for 6h, the tensile strength of squeeze casting alloy reached to 472MPa and 475MPa, respectively, and the elongation was 18.9% and 12.7% accordingly. Based on the experimental results, the mechanism of microstructural evolution of squeeze casting Al-Cu-Mg alloy during heat treatment was discussed, and the effect of squeeze casting on the kinetics of solute diffusion and aging precipitation was studied.


2021 ◽  
Author(s):  
Bernoulli Andilab

Incipient melting of secondary phases during solution heat treatment of Al alloys is detrimental to their mechanical properties. In this research, incipient melting was analyzed in-situ using a high temperature Laser Scanning Confocal Microscope (LSCM) in a novel Al-Cu alloy. Thermal analysis and microstructural analysis were carried out on the alloy cast at fast and slow cooling rates to examine the resulting solidification and microstructural characteristics. The results showed that incipient melting was accompanied by a clustering liquid droplets followed by a complete melting of Al2Cu which occurred at approximately 548 ℃. Additionally, the use of LSCM enabled an understanding of the underlying mechanisms behind incipient melting. It was also found that incipient melting led to microstructure that consisted of a higher presence of ultra-fine eutectic clusters, needle-like Al2Cu and porosity along the grain boundaries. Lastly, the solution heat treatment temperature was optimized for the Al-Cu alloy using the data from LSCM, Differential Scanning Calorimetry and solution heat treatment experiments.


2020 ◽  
Vol 405 ◽  
pp. 357-364
Author(s):  
Lenka Kuchariková ◽  
Eva Tillová ◽  
Ivana Švecová

Al-Si-Cu alloy systems have a great importance in the casting industry due to their excellent castability, good mechanical properties and wear resistance. Addition of alloying elements, such as Mg and Cu, makes these alloys heat treatable. Improving of their mechanical properties allows their using in new, more demanding applications (e.g. engines, cylinder heads etc.). The most applied heat treatment for this alloy is a T6 (age hardening). Such a heat treatment is required for precipitation of the Al2Cu hardening dispersed phase that increases the mechanical properties of Al alloys. Therefore, the consequences of different solution heat treatment temperatures 505, 515 and 525 °C for AlSi9Cu3 and 515, 525 and 545 °C for AlSi12Cu1Fe cast alloys, with holding times 2, 4, 8, 16 and 32 hours, were investigated in this study. The effect of solution treatment was evaluated based on changes in microstructure (optical microscopy) and mechanical properties (hardness, impact energy and ultimate tensile strength). The study confirms the strengthening of the experimental alloys caused by application of optimum conditions of T6 and melting of the Cu-rich phases with application of inappropriate solution temperature, as well as distortion and changes of the testing bars.


2014 ◽  
Vol 788 ◽  
pp. 187-192 ◽  
Author(s):  
Lei Lu ◽  
Da Tong Zhang ◽  
Yuan Yuan Li

The effects of heat treatment on the microstructures and mechanical properties of a squeeze-casted Al-6.8%Zn-2.7%Mg-2.0%Cu alloy were studied by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is found that squeeze casting can refine the microstructure of the alloy markedly accelerates the diffusion process of solute atoms during solution heat treatment. After solution heat treatment at 470°C for 10h and artificial aging at 130°C for 24h, the tensile strength and the elongation of the squeeze-casted alloy reach 590MPa and 5.0%, respectively, which are almost equal to those of the wrought alloy, and are significantly higher than those of the gravity-casted alloy (435MPa and 1.3%). Based on the experimental results, the mechanism of microstructural evolution and the effect of squeeze casting on the kinetics of solute diffusion and aging precipitation of the squeeze-casted Al-Zn-Mg-Cu alloy were discussed.


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