Forging Studies with Severe Plastic Deformation Processed Aluminum Alloy 6061

2003 ◽  
Vol 426-432 ◽  
pp. 267-272 ◽  
Author(s):  
R. Srinivasan ◽  
Prabir K. Chaudhury
2020 ◽  
Vol 835 ◽  
pp. 186-192
Author(s):  
Gehan A. Abd El Raouf ◽  
N. El Mahallawy ◽  
M.K. Shoukry

Cyclic extrusion compression (CEC) is one of the well-known techniques in metal forming processes under the severe plastic deformation process (SPD) in which an ultra-large plastic strain is imposed on a bulk material in order to make ultra-fine grained (UFG) metals, alloys and composites. In this work, the mechanical properties of the aluminum alloy (6061) before and after CEC process were examined. A special CEC die was design and fabricated for the present work which achieved an effective plastic strain of about 0.62 after each separate cycle of CEC. The microstructure was effectively refined with increasing the number of CEC cycles as the grain size was reduced from ≈250μm to ≈30 μm after 6 cycles of CEC. The mechanical properties were tremendously increased in comparison with those of as cast and annealed condition. The micro-hardness increased from 25 Hv to 56 Hv, while the yield and the ultimate tensile strengths increased from 60 MPa to 198 MPa and 85 MPa to 204 MPa respectively, the ductility increased from 2.97% to 4.6% with the number of CEC cycles increasing up to six cycles.


2016 ◽  
Vol 716 ◽  
pp. 692-699 ◽  
Author(s):  
Alexander Pesin ◽  
Denis Pustovoytov

Aluminum and its alloys are widely used as structural materials in aerospace, automotive and other industries due to low density and high specific strength. Efficient way to increase strength and other properties of aluminum alloys is to form an ultra fine grain structure using severe plastic deformation methods. Cryogenic asymmetric sheet rolling under liquid nitrogen temperature is a process of severe plastic deformation that can be used to improve the aluminum alloys structure and properties. Prediction of sheet temperature during plastic deformation is very important. The temperature of sheet is changed due to the conversion of mechanical work of deformation into heat through sliding on contact surfaces. This paper presents the results of the finite element simulation of heat transfer during cryogenic asymmetric sheet rolling of aluminum alloy 6061. The effect of thickness reduction, rolling velocity and friction coefficient on the deformation heating and temperature field of aluminum alloy 6061 was found. The results of investigation could be useful for the development of the optimal treatment process of aluminum alloys by cryogenic severe plastic deformation to obtain the ultra fine grain structure and high strength properties.


1962 ◽  
Vol 84 (1) ◽  
pp. 53-62 ◽  
Author(s):  
E. G. Thomsen ◽  
A. G. MacDonald ◽  
S. Kobayashi

Orthogonal cutting tests with artificial flank-wear lands were performed on steel SAE 1112 as-received (cold-drawn), steel SAE 4135 as-received (cold-drawn), aluminum alloy 6061-T6 (extruded), and alpha-brass as cold-drawn. Forces, workpiece temperature, average tool temperatures, and other pertinent data were taken. Each test was of short duration (approximately 10 revolutions of the workpiece or less) and the tools were reconditioned between each test run. The results show that, for steel SAE 1112, steel SAE 4135, and aluminum alloy 6061-T6, sublayer flow appears to take place when the flank wear-land clearance angle is set to a negative angle of magnitude −1 deg and the land is approximately 0.010 to 0.020 in. long. The condition for sublayer flow is predictable based on the state of plastic deformation and the stress-strain properties, at temperature and at appropriate strain rates for these materials.


2014 ◽  
Vol 1024 ◽  
pp. 219-222
Author(s):  
Soon Vern Yee ◽  
Zuhailawati Hussain ◽  
Anasyida Abu Seman ◽  
Muhammad Syukron ◽  
Indra Putra Almanar

Equal Channel Angular Pressing (ECAP) is one of Severe Plastic Deformation (SPD) methods used to produce ultra-fine grains. In this study, aluminum alloy 6061 in a rod shape as a result from casting process was used in the experiment. The rod samples were then subjected to ECAP, up to 3 passes, through Bc route. The die channel angle of the ECAP is 1200. The changes in the microstructure and mechanical properties of the samples deformed by 1-pass, 2-pass, and 3-pass of ECAP were investigated. The results show that as number of ECAP passes increase, the applied strain accumulated in the samples also increases and the grains change from equiaxed to elongated structure. The hardness is proportional to the number of ECAP passes, and the highest value is 107 HV for 3 passes with strain value of 2.0.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 954
Author(s):  
Hailong Wang ◽  
Wenping Deng ◽  
Tao Zhang ◽  
Jianhua Yao ◽  
Sujuan Wang

Material properties affect the surface finishing in ultra-precision diamond cutting (UPDC), especially for aluminum alloy 6061 (Al6061) in which the cutting-induced temperature rise generates different types of precipitates on the machined surface. The precipitates generation not only changes the material properties but also induces imperfections on the generated surface, therefore increasing surface roughness for Al6061 in UPDC. To investigate precipitate effect so as to make a more precise control for the surface quality of the diamond turned Al6061, it is necessary to confirm the compositions and material properties of the precipitates. Previous studies have indicated that the major precipitate that induces scratch marks on the diamond turned Al6061 is an AlFeSi phase with the composition of Al86.1Fe8.3Si5.6. Therefore, in this paper, to study the material properties of the AlFeSi phase and its influences on ultra-precision machining of Al6061, an elastoplastic-damage model is proposed to build an elastoplastic constitutive model and a damage failure constitutive model of Al86.1Fe8.3Si5.6. By integrating finite element (FE) simulation and JMatPro, an efficient method is proposed to confirm the physical and thermophysical properties, temperature-phase transition characteristics, as well as the stress–strain curves of Al86.1Fe8.3Si5.6. Based on the developed elastoplastic-damage parameters of Al86.1Fe8.3Si5.6, FE simulations of the scratch test for Al86.1Fe8.3Si5.6 are conducted to verify the developed elastoplastic-damage model. Al86.1Fe8.3Si5.6 is prepared and scratch test experiments are carried out to compare with the simulation results, which indicated that, the simulation results agree well with those from scratch tests and the deviation of the scratch force in X-axis direction is less than 6.5%.


2010 ◽  
Vol 667-669 ◽  
pp. 925-930
Author(s):  
S.V. Krymskiy ◽  
Elena Avtokratova ◽  
M.V. Markushev ◽  
Maxim Yu. Murashkin ◽  
O.S. Sitdikov

The effects of severe plastic deformation (SPD) by isothermal rolling at the temperature of liquid nitrogen combined with prior- and post-SPD heat treatment, on microstructure and hardness of Al-4.4%Cu-1.4%Mg-0.7%Mn (D16) alloy were investigated. It was found no nanostructuring even after straining to 75%. Сryodeformation leads to microshear banding and processing the high-density dislocation substructures with a cell size of ~ 100-200 nm. Such a structure remains almost stable under 1 hr annealing up to 200oC and with further temperature increase initially transforms to bimodal with a small fraction of nanograins and then to uniform coarse grained one. It is found the change in the alloy post–SPD aging response leading to more active decomposition of the preliminary supersaturated aluminum solid solution, and to the alloy extra hardening under aging with shorter times and at lower temperatures compared to T6 temper.


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