Forging of Articles out of Aluminum Alloys under Superplastic Conditions – Difficulties and Methods of their Overcoming

2012 ◽  
Vol 735 ◽  
pp. 284-288
Author(s):  
Vadim Trifonov
Keyword(s):  
Aluminum Alloys ◽  
Superplastic Deformation ◽  
Hot Forging ◽  
Grain Structure ◽  
Heat Processing ◽  
Corrosion Properties ◽  
Fine Grain ◽  
Mechanical And Corrosion Properties

The manuscript considers the possibility of using of superplastic deformation at hot forging of aluminum alloys. The analysis has been conducted concerning the use of different methods for imparting ultra-fine grain structure to aluminum alloys in terms of their workability. The deformation and heat processing for thermo-strengthened aluminum alloys has been proposed in which superplastic deformation is combined with hardening. The effect of such processing on mechanical and corrosion properties of aluminum alloys is shown. The model processing of a component is demonstrated at forging under superplasticity conditions often surpass the advantages obtained.

scholarly journals Mechanical behavior and corrosion properties of some AA6xxx aluminum alloys in T5 temper

2006 ◽  
Vol 12 (4) ◽  
pp. 231-235
Author(s):  
Kemal Delijic ◽  
Vanja Asanovic ◽  
Dragan Radonjic
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloys ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Continuous Cast ◽  
Corrosion Properties ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium ◽  
The Press ◽  
Mechanical And Corrosion Properties

The paper describes the mechanical and corrosion properties of three heat treatable extruded Al-Mg-Si aluminum alloys. The alloys were tested as T5 tempered (air-quenched directly on the press and artificially aged) after processing by the extrusion of semi-continuous cast and homogenized billets. The addition of small amounts of zirconium and manganese in the base AIMgSiO.7 alloy increased the strength, reaching 310 MPa of tensile strength and increased the corrosion rate by 15% in aqueous sodium chloride solution.

Finite Element Simulation of Heat Transfer during Cryogenic Asymmetric Sheet Rolling of Aluminum Alloys

2016 ◽  
Vol 716 ◽  
pp. 692-699 ◽  
Author(s):  
Alexander Pesin ◽  
Denis Pustovoytov
Keyword(s):  
Heat Transfer ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Severe Plastic Deformation ◽  
Grain Structure ◽  
Sheet Rolling ◽  
Fine Grain ◽  
Element Simulation ◽  
Alloy 6061

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.

scholarly journals Mechanical and corrosion properties of 6061 aluminum alloys recycled by hot-extrusion of cutting chips

2003 ◽  
Vol 53 (11) ◽  
pp. 554-560 ◽  
Author(s):  
Kazutaka SUZUKI ◽  
Ichinori SHIGEMATSU ◽  
Yuan-bin XU ◽  
Tsunemichi IMAI ◽  
Naobumi SAITO
Keyword(s):  
Aluminum Alloys ◽  
Hot Extrusion ◽  
Corrosion Properties ◽  
Mechanical And Corrosion Properties

scholarly journals Simulation of Primary Particle Development and Their Impact on Microstructural Evolution of Sc-Modified Aluminum Alloys during Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1056
Author(s):  
Mohammad Sadegh Mohebbi ◽  
Vasily Ploshikhin
Keyword(s):  
Aluminum Alloys ◽  
Scanning Speed ◽  
Grain Structure ◽  
Coarse Grained ◽  
2D Simulation ◽  
Fine Grain ◽  
Precipitation Model ◽  
Intermetallic Particles ◽  
Experimental Findings

The microstructures of additively manufactured Sc- and Zr-modified aluminum alloys are significantly influenced by the nucleation role of solid intermetallic particles in undercooled liquid. To replicate such effects, a precipitation model relying on L12-Al3Sc particles is developed. An initiation criterion is proposed based on the precipitation kinetics of primary particles to address solute trapping under high solidification rates. Avrami’s equation is then used to estimate the progress of precipitation. The model is integrated into a cellular automata (CA) analysis to simulate the resulting solidified microstructure, in that the precipitation model is performed implicitly within the CA cells. It is shown that, in accordance with the experimental findings, the proposed simulation approach can predict the distinct fine- (FG) and coarse-grained (CG) zones at the fusion boundary and the meltpool core, respectively. The model can also deliver the reported enhancement of the FG zone under lower scanning speed and higher platform temperatures. These findings are explained in terms of particle number densities at different meltpool regions. Moreover, a semi-2D simulation with a very small cell size is suggested to address the extremely fine grain structure within the FG zone.

New Grain Formation in a Coarse-Grained 7475 Al Alloy during Severe Hot Forging

2004 ◽  
Vol 467-470 ◽  
pp. 421-428 ◽  
Author(s):  
Oleg Sitdikov ◽  
Tetsuo Sakai ◽  
Alexandre Goloborodko ◽  
Hiromi Miura ◽  
Rustam Kaibyshev
Keyword(s):  
Grain Refinement ◽  
Hot Forging ◽  
Grain Boundary Sliding ◽  
Grain Structure ◽  
Coarse Grained ◽  
Al Alloy ◽  
Continuous Dynamic Recrystallization ◽  
Multidirectional Forging ◽  
Fine Grain ◽  
Continuous Dynamic

Strain-induced grain refinement in a coarse-grained 7475Al alloy was studied by means of multidirectional forging (MDF) carried out at T = 490oC under a strain rate of 3 x 10-4 s-1. Integrated flow curves exhibit significant work softening just after yielding, followed by steady-state-like behavior at high strains. The evolution of new fine grain structure during deformation can be assisted by grain-boundary sliding, resulting in frequent formation of high strain gradients and subsequently microshear bands in grain interiors. Microshear bands developed in various directions are intersected with each other, subdividing original grains into misoriented small domains. The number and the misorientation angle of microshear bands progressively increase during deformation, finally followed by their transformation into high-angle boundaries. It is concluded that grain refinement under hot MDF conditions occurs by a series of deformation-induced continuous reactions; that is essentially similar to continuous dynamic recrystallization.

scholarly journals Bimodal Microstructure Obtained by Rapid Solidification to Improve the Mechanical and Corrosion Properties of Aluminum Alloys at Elevated Temperature

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 230
Author(s):  
Irena Paulin ◽  
Črtomir Donik ◽  
Peter Cvahte ◽  
Matjaž Godec
Keyword(s):  
Elevated Temperature ◽  
Aluminum Alloys ◽  
Melt Spinning ◽  
High Strength ◽  
Tensile Tests ◽  
Chemical Compositions ◽  
Corrosion Properties ◽  
Transmission Microscopy ◽  
Aa5083 Alloy ◽  
Mechanical And Corrosion Properties

The demand for aluminum alloys is increasing, as are the demands for higher strength, with the aim of using lighter products for a greener environment. To achieve high-strength, corrosion-resistant aluminum alloys, the melt is rapidly solidified using the melt-spinning technique to form ribbons, which are then plastically consolidated by extrusion at elevated temperature. Different chemical compositions, based on adding the transition-metal elements Mn and Fe, were employed to remain within the limits of the standard chemical composition of the AA5083 alloy. The samples were systematically studied using light microscopy, scanning electron, and transmission microscopy with electron diffraction spectrometry for the micro-chemical analyses. Tensile tests and Vickers microhardness were applied for mechanical analyses, and corrosion tests were performed in a comparison with the standard alloy. The tensile strength was improved by 65%, the yield strength by 45% and elongation by 14%. The mechanism by which we achieved the better mechanical and corrosion properties is explained.

Microstructural, mechanical and corrosion properties of dissimilar joint between AISI A321 stainless steel and ASTM A537CL1 structural steel produced by GTAW process

2019 ◽  
Vol 116 (4) ◽  
pp. 418 ◽  
Author(s):  
Behnam Sadeghi ◽  
Hassan Sharifi ◽  
Mahdi Rafiei ◽  
Ahmad Reza Abbasian ◽  
Ehsan Saebnoori
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Dendritic Structure ◽  
Welding Process ◽  
Optical Microscope ◽  
Dissimilar Joint ◽  
Corrosion Properties ◽  
Fine Grain ◽  
Gtaw Process ◽  
Mechanical And Corrosion Properties

In this research, the microstructural, mechanical and corrosion properties of the dissimilar joint of ASTM A537CL1 to AISI A321 steels produced by GTAW process were studied. The welding process was done with ER308L filler metal without pre and post weld heat treatment. The scanning electron microscope and optical microscope were used to study the microstructure and fracture surface of the welded samples. Also, the mechanical behavior of the joint was evaluated by impact, tensile, bending and microhardness tests. The results illustrated that the microstructure of the weld metal was austenite with dendritic structure contained skeletal and lathy ferrite. In tension tests, all weldments failed from A537 base metal. The results of impact test indicated that all specimens exhibit ductile fracture and indicated high impact energy of about 205 J. In fine grain HAZ of A537 steel, because of formation of fine equiaxed grains due to the allotropic transformation, high microhardness was seen. While, in coarse grain HAZ, due to the formation of bigger grains, carbon migration and decreasing in the amount of pearlite phase, the microhardness slightly decreased. The exsistence of chromium in microstructure improved the corrosion resistance and the weld metal indicated acceptable corrosion resistance as compared with both base metals.

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