Effect of Heat Treatment on the Mechanical Properties of Wrought Al-Zn-Mg-Cu Alloy Cast by Rapid Solidification

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.

2008 ◽  
Vol 584-586 ◽  
pp. 182-187
Author(s):  
Lilia Kurmanaeva ◽  
Yulia Ivanisenko ◽  
J. Markmann ◽  
Ruslan Valiev ◽  
Hans Jorg Fecht

Investigations of mechanical properties of nanocrystalline (nc) materials are still in interest of materials science, because they offer wide application as structural materials thanks to their outstanding mechanical properties. NC materials demonstrate superior hardness and strength as compared with their coarse grained counterparts, but very often they possess a limited ductility or show low uniform elongation due to poor strain hardening ability. Here, we present the results of investigation of the microstructure and mechanical properties of nc Pd and Pd-x%Ag (x=20, 60) alloys. The initially coarse grained Pd-x% Ag samples were processed by high pressure torsion, which resulted in formation of homogenous ultrafine grain structure. The increase of Ag contents led to the decrease of the resulted grain size and change in deformation behavior, because of decreasing of stacking fault energy (SFE). The samples with larger Ag contents demonstrated the higher values of hardness, yield stress and ultimate stress. Remarkably the uniform elongation had also increased with increase of strength.


2014 ◽  
Vol 14 (2) ◽  
pp. 57-62
Author(s):  
M. Szymaneka ◽  
B. Augustyn ◽  
D. Kapinos ◽  
S. Boczkal ◽  
J. Nowak

Abstract In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafine grain structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequent fragmentation.


2013 ◽  
Vol 765 ◽  
pp. 511-515 ◽  
Author(s):  
Da Quan Li ◽  
Xiao Kang Liang ◽  
Fu Bao Yang ◽  
You Feng He ◽  
Fan Zhang ◽  
...  

The evolution of microstructure and mechanical properties during solution and ageing heat treatment process was studied in terms of a thixo-diecast impeller of 319s aluminium alloy. The cast alloy exhibited a microstructure consisting of primary uniformly distributed in α-Al globules and the eutectics. A series of heat treatment studies were performed to determine optimum heat treatment parameters, in order to achieve fine grain structure, fine silicon particles and optimal precipitate size and distribution. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the evolution of microstructure and mechanical properties. The results demonstrate that, the full T6 heat treatments are successfully applied to thixo-diecast 319s impellers. A two-step solution heat treatment is employed to prevent porosity due to overheating. The tensile properties of thixo-diecast 319s impellers were substantially enhanced after T6 heat treatment. The plate-shaped θ′ precipitates and lath-shaped Q′ precipitates are the most effective for precipitation strengthening.


2015 ◽  
Vol 22 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Zejun Chen ◽  
Quanzhong Chen ◽  
Qing Liu ◽  
Zheng Zhou ◽  
Guojun Wang

AbstractThe ultrafine grain structure is very difficult to fabricate by severe plastic deformation (SPD) for metals with poor formability. In this paper, a fabrication technology of ultrafine structured dissimilar laminated metal composite sheets (LMCS) was developed for poor plastic metals which have low elongation by hot accumulative roll bonding (ARB) in conjunction with cold rolling. The hot ARBed 1100/7075 LMCS was cold rolled at room temperature after recrystallization annealing treatment. An ultrafine structured dissimilar LMCS was obtained without undergoing severe cold rolled deformation. The mechanical properties were enhanced and optimized by using heat treatment technology. The accelerated refining mechanism of grain was revealed by microstructure characterization of the composite sheet. The enhanced strength was mainly derived from the fine layers, refined grains, increased dislocation accumulation, and abundant dispersoids. The results of the research are helpful in improving the mechanical properties of dissimilar LMCS and optimizing the preparation technology.


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 59 (1) ◽  
pp. 317-321 ◽  
Author(s):  
M. Szymanek ◽  
B. Augustyn ◽  
D. Kapinos ◽  
S. Boczkal ◽  
J. Nowak

Abstract The paper presents the technological aspect of the process of casting, crushing and plastic consolidation of semi-finished products from magnesium alloy. The aim of this study was to produce by the rapid solidification process a magnesium alloy from the MgAl9Zn1 family in the form of ribbons with ultrafine grain structure. The material cast in the melt spinning device was next crushed and subjected to the operation of cold consolidation and hot extrusion. The paper presents different stages of the process, including initial characterisation of the obtained material.


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.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 910 ◽  
Author(s):  
Tian-Le Liu ◽  
Jin-Feng Li ◽  
Dan-Yang Liu ◽  
Yun-Long Ma

In this paper, the microstructure evolution of the 2195 Al-Li alloy under different isothermal annealing schedules and ramp heating-up heat treatments prior to solution heat treatment and the tensile properties of the aging alloy were investigated. The grain structure characteristics of the aging alloy could be influenced by the change of different heat treatment schedules prior to the solution heat treatment. Meanwhile, the mechanical properties of the aging alloy including strength, heterogeneity, and anisotropy were closely related to the grain structure characteristics. There were evident differences in the mechanical properties of aging samples, attributed to the mutual effect of grain structure evolution and texture change. Annealing at a lower temperature (300–350 °C) resulted in the growth of the grain size and the aspect ratio as well as the decrease of the deformation texture components, related to the decline of the strength and the heterogeneity. While grains refined and the deformation texture components increased as the annealing temperature rose (350–400 °C), the strength along the transverse direction decreased, and the heterogeneity increased. Fibrous and overall texture components significantly strengthened in the grain structure of aging samples treated with the low heating-up rate, resulting in a higher strength in the longitudinal direction.


2018 ◽  
Vol 1 (1) ◽  
pp. 77-90
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen A. Hassan

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.


2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.


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