Uphill Quenching of Aluminum Alloys

Author(s):  
Wellington da Silva Mattos ◽  
George Edward Totten ◽  
Lauralice de Campos Franceschini Canale

This article describes the concept of uphill quenching process applied in the heat treatment of aluminum alloys. Uphill quenching is interesting since residual stress reductions of up to 80% has been reported. In addition, substantial improvements in dimensional stability have been achieved for several types of aluminum parts. Often, uphill quenching is applied after quenching and before aging during the heat treatment of aluminum alloys. The uphill quenching process consists of the immersion of the part in a cryogenic environment, and after homogenization of the temperature, the part is transferred to the hot steam chamber to obtain a temperature gradient that will maintain the mechanical properties gained with this process. The results obtained are lower residual stress and better dimensional stability. The aim of this article is to provide a review of this process and to compare it with conventional heat treatment.

2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


2018 ◽  
Vol 734 ◽  
pp. 299-310 ◽  
Author(s):  
L.F. Wang ◽  
J. Sun ◽  
X.L. Yu ◽  
Y. Shi ◽  
X.G. Zhu ◽  
...  

2019 ◽  
Vol 950 ◽  
pp. 75-79
Author(s):  
Zhen Hai Xu ◽  
Chao Ran Ding ◽  
De Bin Shan

With the ever-increasing concern about the energy and environment crises, aluminum alloys are becoming increasingly desirable in the automotive, aerospace, construction and other related industries due to their high specific strength. Various heat-treatment–stamping integrated techniques have been invented to address the formability challenge of aluminum alloy sheets. Electric field affects the heat treatment process of aluminum alloys. In this paper, a device for application of electric field during the heat treatment was developed. The maximum dimensions of specimen are determined via observing the distortion of metal sheets after quenching in cool water. The high-temperature resistant pure nickel wire gains a high-voltage proof performance by wearing bowl-shaped porcelain tubes, and is used to connect electrodes to power supply. The high-voltage resistant mica plates are bolted together to fill the gap between the specimen and electrode. This device was then used in a common commercial furnace to study the effect of electric field applied during the heat treatment on mechanical properties of AA 6082 sheets. It is found that electric field could enhance mechanical properties of AA 6082. The application of electric field has a potential to lower the cost of heat-treatment–stamping integrated techniques.


Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 147 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Axel von Hehl

Most heat treatment simulations of precipitation-hardenable aluminum alloys are incomplete or restricted to sub-steps of the process chain. In general, the studies addressing the heat treatment of aluminum components have only provided a qualitative guidance of heat treatment, which does not match the heat treatment that is necessary for specific parts with specific requirements. Thus, a quick and accurate simulation of the whole heat treatment process would hold great economic benefit for industrial applications in predicting suitable heat treatment processes that are able to meet the required mechanical properties of proposed novel aluminum components. In this paper, the development of a time and cost efficient method for generating such prediction models is presented by means of an example aluminum alloy EN AW-6082. During the process sub-steps of solution annealing, quenching and aging, the time-temperature correlations connected to the precipitation-hardening conditions were analyzed. The precision of the prediction model depends on the size of the material database, which should be able to be adjusted to the individual requirements of the simulation user. In order to obtain the greatest time and cost efficiency in generating such a model, a specific experimental design was developed. The results of the method development are presented and discussed.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 920 ◽  
Author(s):  
Lin Yang ◽  
Hong-Hai Liu

Wood is an environmentally friendly material, but some natural properties limit its wide application. To study the effect of a combination of heat treatment (HT) and wax impregnation (WI) on wood hygroscopicity, dimensional stability, and mechanical properties, samples of Pterocarpus macrocarpus Kurz wood were subjected to HT at a moderate temperature of 120 °C and a high temperature of 180 °C, for a 4 h duration. Subsequently, half of the 120 °C HT samples were treated with WI at 90 °C. The results showed that 180 °C HT and WI decreased the capacity of adsorption and liquid water uptake and swelled the wood significantly, while WI had the biggest reduction. The effect of 120 °C HT was significant only on decreasing the capacity of adsorption and the swelling of liquid water uptake. The bending strength (MOR) of wood decreased only after 180 °C HT, and 120 °C/4h HT and WI had no significant influence on MOR. The bending stiffness (MOE) increased significantly after 180 °C HT and WI, while 120 °C/4h HT had no significant influence on MOE. Therefore, the combination of moderate-temperature HT can act synergistically in the improvement of certain aspects of wood properties such as capacity of water adsorption and liquid water uptake. WI effectively improved wood hygroscopicity, dimensional stability, and mechanical properties.


2013 ◽  
Vol 845 ◽  
pp. 398-402 ◽  
Author(s):  
Chinnasamy Muthazhagan ◽  
A. Gnanavelbabu ◽  
G.B. Bhaskar ◽  
K. Rajkumar

This paper deals with the mechanical properties in conventional heat treatment of Al (6061)-B4C-Graphite. Aluminium Metal Matrix Composites (MMC) is fabricated through two step stir casting method. The composites were fabricated with various volume percentage levels as Aluminium reinforced with (5, 10 &15%) Boron Carbide and (5,10 & 15%) of Graphite. Fabricated composites were subjected to conventional heat treatment for enhancing the mechanical properties. Influences of Graphite reinforcement on mechanical properties of Aluminum-Boron carbide composites were analyzed. The microstructure studies were also carried out. It is observed that increasing the graphite content within the aluminum matrix results in significant decrease in ductility, hardness, ultimate tensile strength. The addition of boron carbide conversely increased the hardness of the composites.


2012 ◽  
Vol 472-475 ◽  
pp. 1132-1134
Author(s):  
Jin Sun ◽  
Xiao Bo Wang ◽  
Xiao Jing Wang ◽  
Yan Lin ◽  
Zhen Zhong Gao

Five hardwood species (Schima superba Gardn, kapur( Dryobalanops sp.), ash (Fraxinus mandshurica Rupr.), birch(Betula platyphylla Suk.), tauari (Couratari sp.)) were conducted the Heat treatment at 185°C.. The results indicated that the dimensional stability, modulus of elasticity (MOE) increased greatly while the wettability decreased after treatment. There was a negative impact of heat treatment on MORs.


2017 ◽  
Vol 67 (2) ◽  
pp. 109-116
Author(s):  
Branislav Vanko ◽  
Ladislav Stanček ◽  
Roman Moravčík

AbstractBy using the wrought aluminum alloys can be created castings with higher mechanical properties than the castings made of standard foundry aluminum alloys, but it is necessary to handle the process of making sound castings without any defects such as hot tears and shrinkage porosity. In experiments, we have been studied of wrought aluminum alloy EN AW-2024 which has been processed by the casting with crystallization under pressure with forced flow. Castings were heat treated by standard T6 heat treatment.


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