Effects of Homogenization Conditions on the Microstructures of Twin-Roll Cast Foil Stock of AA8021 Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 296-302
Author(s):  
Wei Chen ◽  
Pi Zhi Zhao ◽  
Yu Li Zhou ◽  
Yan Feng Pan
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Foil ◽  
Grain Structure ◽  
Medium Temperature ◽  
Grain Structures ◽  
Temperature Homogenization ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Homogenization Condition

AA8021 aluminum alloy twin-roll cast strips with 7mm gauge were rolled to 3.8mm gauge sheets and given homogenization, further rolled into 0.55mm gauge foil stocks with intermediate annealing. This paper investigated the influence of homogenization conditions on microstructures of foil stocks in detail. The results show that, for the foil stock made from the sheet without homogenization, the grain structure is partially recrystallized. While the grain structure of foil stock made from the sheet with medium temperature homogenization is fully recrystallized, but it is coarse near sheet surface. However, foil stock made from the sheet with high temperature homogenization has fine and uniform recrystallized grain structures. The differences of grain structures among these three kinds of foil stocks can be understood by the variation in solid solution content of Fe, Si, Mn and distribution of intermetallic compounds. The optimized homogenization condition was adopted by our plant to produce foil stock, and its grain structure was fine and uniform. The surface quality of final aluminum foil rolled from the foil stock could meet high grade requirements of customers.

Recrystallization Behavior of Twin-Roll Cast 3xxx Series Aluminum Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1257-1262 ◽  
Author(s):  
Michihide Yoshino ◽  
Shohei Iwao ◽  
Masakazu Edo
Keyword(s):  
Aluminum Alloy ◽  
Direct Chill ◽  
Grain Structure ◽  
Thin Plates ◽  
Recrystallization Behavior ◽  
Roll Casting ◽  
Cold Rolling Reduction ◽  
Series Aluminum Alloy ◽  
Twin Roll Cast ◽  
Twin Roll

Twin roll casting (TRC) is an efficient process used to produce thin plates directly from molten metal. However, TRC has a much higher cooling rate during solidification compared with conventional direct chill casting. Accordingly, the constituent phases are refined and the added elements are supersaturated by this casting method. Supersaturation of the added elements hinders both recovery and recrystallization because fine dispersoids precipitate from the supersaturated solid solution during annealing [ and coarsen the grain size of the final plate, which leads to degradation of formability. Therefore, it is important to understand the influence of the solute element and dispersoids on recrystallization behavior to obtain an appropriate grain structure for forming. In this study, the effects of the homogenization conditions and cold rolling reduction on the recrystallization behavior of twin-roll cast 3XXX series aluminum alloy were investigated.

Experimental Evaluation of the Chill Casting Method for the Fabrication of LM-25 Aluminum Alloy-Borosilicate Glass (p) Composites

2017 ◽  
Vol 748 ◽  
pp. 69-73 ◽  
Author(s):  
Anupama Hiremath ◽  
Joel Hemanth
Keyword(s):  
Aluminum Alloy ◽  
Borosilicate Glass ◽  
Metallic Copper ◽  
Matrix Material ◽  
Weight Percent ◽  
Grain Structure ◽  
Matrix Composites ◽  
Hardness Tests ◽  
Result Analysis

The paper investigates the novelty of application of end chills in fabricating Aluminum alloy metal matrix composites. An effort has also been made to evaluate the effect of chill material on the soundness of the castings obtained. The required composites were prepared using LM-25 Aluminum alloy as matrix material in which different weight percent of Borosilicate glass particles were added ranging from 3 wt.% to 12 wt.%. The variation in weight percent was brought about in steps of 3%. The fabrication of the composites was carried out in sand molds by incorporating two metallic (copper and Steel) and two non-metallic (Graphite and Silicon carbide) end chills. The specimens for strength and hardness tests were prepared as per ASTM standards and the specimens were drawn from near chill-end as well as from farther away from chill end. The microstructure of the specimens reveal a refined grain structure proving the sound quality of the castings. The result analysis also leads to the conclusion that metallic chills are more beneficial as compared to non-metallic chills for obtaining a good quality composites. Copper chill with a high volumetric heat capacity proved to be the best chill material amongst the others.

Forming of Small Projection on Roll-Cast A356 Strip by Cold Rolling and Small Groove on PET Plate Using A356 Die

2019 ◽  
Vol 805 ◽  
pp. 37-42
Author(s):  
Toshio Haga ◽  
Yhuta Nakazawa
Keyword(s):  
Aluminum Alloy ◽  
Cold Rolling ◽  
Polyethylene Terephthalate ◽  
Alloy Sheet ◽  
Rolling Speed ◽  
A356 Aluminum Alloy ◽  
Aluminum Alloy Sheet ◽  
A356 Aluminum ◽  
Twin Roll Cast ◽  
Twin Roll

A small projection with a height and width of about 40 and 50 µm, respectively, was formed on a twin-roll-cast A356 aluminum alloy sheet by cold rolling at a rolling speed of 0.5 m/min. This projection was then used as a die to form a groove with a depth and width of about 40 and 50 µm, respectively, on a polyethylene terephthalate plate by pressing.

Near-Surface Microstructure on Twin-Roll Cast 8906 Aluminum Alloy

2015 ◽  
Vol 46 (6) ◽  
pp. 2688-2695 ◽  
Author(s):  
Junjie Wang ◽  
Xiaorong Zhou ◽  
George E. Thompson ◽  
John A. Hunter ◽  
Yudie Yuan
Keyword(s):  
Aluminum Alloy ◽  
Surface Microstructure ◽  
Near Surface ◽  
Twin Roll Cast ◽  
Twin Roll

scholarly journals A Novel Approach to Improve the Microstructure and Mechanical Properties of Al–Mg–Si Aluminum Alloys during Twin-Roll Casting

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1713 ◽  
Author(s):  
Yong Li ◽  
Chen He ◽  
Jiadong Li ◽  
Zhaodong Wang ◽  
Di Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Crystallization Front ◽  
Alloying Elements ◽  
Cast Slab ◽  
Energy Dispersion Spectroscopy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll Cast ◽  
Twin Roll

The main purpose of this present study was to investigate the different processing conditions on the microstructure, segregation behavior of alloying elements, and mechanical properties of Al−Mg−Si alloy twin-roll cast slab prepared using a novel twin-roll casting technology. The simulation of temperature field, distribution of alloying elements, tensile properties, hardness, and conductivity were examined by a Leica optical microscope, scanning electron microscopy, energy dispersion spectroscopy, electron probe microanalysis, and tensile tests. The results indicated that when the traditional twin-roll casting method was used to produce aluminum alloy strip, there are obvious centerline segregation defects due to the deep crystallization front depth and symmetrical solidification characteristics. When the forced-cooling technology was applied in the twin-roll casting process, by virtue of the changing of crystallization front depth and crystallization front shape, the segregation defects are obviously suppressed. Suggesting that this method can significantly improve the uniformity of alloying elements in the thickness direction of the twin-roll cast slab, ultimately improve the mechanical properties of AA6022 aluminum alloy.

scholarly journals Determination of the Hot Cracking Tendency of a Twin-Roll Cast AZ31 Magnesium Alloy by Means of Gleeble Tests

2018 ◽  
Vol 918 ◽  
pp. 40-47
Author(s):  
Heike Wemme ◽  
Christina Krbetschek ◽  
Madlen Ullmann ◽  
Anna Freigang ◽  
Stefan Plach ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Az31 Alloy ◽  
Hot Cracking ◽  
Az31 Magnesium Alloy ◽  
Cast Magnesium ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Cracking Tendency

The knowledge about the formation of hot cracking in magnesium alloys, such as in twin-roll cast magnesium sheets and strips, is fundamental for a good quality of the strips during the further processing by rolling or welding and minimize the reject. Hot cracking often occurs in the so-called mushy zone, when solid phases and melt coexist, at temperatures where the material no longer exhibits ductility. For the evaluation of the hot cracking tendency of an alloy, the width of the HTBR (High-temperature brittleness range) can be used. On the basis of a test on a Gleeble HDS-V40, the HTBR was determined for a twin-roll cast AZ31 magnesium alloy. The transition between ductile forming behaviour and complete brittle reaction of the AZ31 alloy is confirmed by the observation of the fracture surfaces (determination of the fracture type) in the scanning electron microscope (SEM) and is located at 555 °C. The HTBR shows a range 35 K.

Effect of Homogenization on Recrystallization of Twin Roll Cast AA3003 Alloy

2013 ◽  
Vol 404 ◽  
pp. 122-126
Author(s):  
Yi You Tu ◽  
De Zhong Zhang
Keyword(s):  
Annealing Temperature ◽  
Volume Fraction ◽  
Resistivity Measurement ◽  
Optical Microscope ◽  
Intermetallic Particles ◽  
Temperature Homogenization ◽  
Homogenization Temperatures ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Electric Resistivity Measurement

The effect of homogenizations on the recrystallization microstructure of as-rolled twin roll cast AA3003 alloy were investigated using optical microscope, scanning electron microscopy and electric resistivity measurement. The results indicate that high temperature homogenization significantly decrease the supersaturation of Mn in the alloy, and both the volume fraction and the diameter of intermetallic particles increase as the homogenization temperatures. The shape of the recrystallized grains changes from pancake-like to equiaxed, as the annealing temperature increases above 520°C.

scholarly journals Microstructure and Hot Deformation Behavior of Twin Roll Cast Mg-2Zn-1Al-0.3Ca Alloy

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1020 ◽  
Author(s):  
Kristina Kittner ◽  
Madlen Ullmann ◽  
Thorsten Henseler ◽  
Rudolf Kawalla ◽  
Ulrich Prahl
Keyword(s):  
Hot Deformation ◽  
Deformation Behavior ◽  
Flow Instability ◽  
Grain Structure ◽  
Strain Rates ◽  
Compression Tests ◽  
Cast State ◽  
Hot Deformation Behavior ◽  
Twin Roll Cast ◽  
Twin Roll

In the present work, the microstructure, texture, mechanical properties as well as hot deformation behavior of a Mg-2Zn-1Al-0.3Ca sheet manufactured by twin roll casting were investigated. The twin roll cast state reveals a dendritic microstructure with intermetallic compounds predominantly located in the interdendritic areas. The twin roll cast samples were annealed at 420 °C for 2 h followed by plane strain compression tests in order to study the hardening and softening behavior. Annealing treatment leads to the formation of a grain structure, consisting of equiaxed grains with an average diameter of approximately 19 µm. The twin roll cast state reveals a typical basal texture and the annealed state shows a weakened texture, by spreading basal poles along the transverse direction. The twin roll cast Mg-2Zn-1Al-0.3Ca alloy offers a good ultimate tensile strength of 240 MPa. The course of the flow curves indicate that dynamic recrystallization occurs during hot deformation. For the validity range from 250 °C to 450 °C as well as equivalent logarithmic strain rates from 0.01 s−1 to 10 s−1 calculated model coefficients are shown. The average activation energy for plastic flow of the twin roll cast and annealed Mg-2Zn-1Al-0.3Ca alloy amounts to 180.5 kJ/mol. The processing map reveals one domain with flow instability at temperatures above 370 °C and strain rates ranging from 3 s−1 to 10 s−1. Under these forming conditions, intergranular cracks arose and grew along the grain boundaries.

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