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Aluminum Alloy Semisolid Strip Casting Using an Unequal Diameter Twin Roll Caster  [PDF]
T. Haga,H. Sakaguchi,H. Inui,H. Watari
Journal of Achievements in Materials and Manufacturing Engineering , 2005,
Abstract: Purpose: A Purpose of the present study was to break through the disadvantage of the twin roll caster for aluminum alloy. They were slow casting speed and limitation of alloy. For example, the casting speed was slower than 5 m/min, and casting of hypereutectic Al-Si alloy was difficult. In order to break through the disadvantages, semisolid casting using an unequal diameter twin roll caster was tested its ability.Design/methodology/approach: The specification of the unequal diameter twin roll caster is as below. The diameter of the upper roll was 250 mm, and that of the lower roll was 1000 mm. The width of the roll was 100 mm. The semisolid slurry was made by a cooling slope.Findings: The microstructure of the strip became very fine. Especially, primary and eutectic Si became very fine. This was the effect of rapid solidification. As the result, the ductility of Al-16%Si was improved.Research limitations/implications: 6111 aluminum alloy strip was cast at speeds of 5, 10 and 20 m/min. This caster could cast the strip at the speeds higher than the conventional twin roll caster. Start of casting was very easy. The hypereutectic Al-16%Si alloy, which has wide freezing zone, could be cast in to the strip by the unequal diameter twin roll caster. This was the effect of the cooling of the strip on the lower roll.Originality/value: The roll cast Al-16mass%Si strip had good ductility, and could be cold rolled. Annealed 0.5 mm thick Al-16mass%Si could be bent at radius of 0.75mm.
Casting of aluminum alloy strip using an unequal diameter twin roll caster  [PDF]
T. Haga,H. Inui,H. Watari,S. Kumai
Archives of Materials Science and Engineering , 2008,
Abstract: Purpose: of this paper is to clear the property and ability of an unequal diameter twin roll caster to castcommercial size strip. Therefore, 400mm-width strip was cast as first step. Surface-condition, microstructure andmechanical property of the strip was investigated.Design/methodology/approach: Method used in the present study was an unequal diameter twin roll caster.This method was devised to realize easy operation of the twin roll casting and increase of casting speed.Findings: are that 400-width-strip of 3084, 5182 and 6022 could be cast at speed of 20 m/min. This strip wasabout 4 mm-thick. There were some defects on the surface. As cast strip could be cold-rolled down to sheetof 1 mm-thick. 180 degrees bending test was operated on the 6022 sheet after T4 heat treatment. Crack did notoccurred at the outer surface when strip was bent at width-direction.Research limitations/implications: is that the quantity of the melt was 21kg and investigation of theproperties was not enough for practical use. The larger weight of melt must be cast for production.Practical implications: are as below. The 400mm-width strip can be cast easily by the unequal diameter twinroll caster. This caster can be adapted to 3083, 5182 and 6022.Originality/value: as below. The economy sheet with 400mm width can be produced by the unequal diameter twinroll caster. 3083, 5182 and 6022 can be cast at the speed of 20m/min. The thickness of the strip was about 4mm.
High speed twin roll casting of 6016 strip  [PDF]
T. Haga,M. Ikawa,H. Watari,S. Kumai
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016aluminum alloy is used for sheet metal of the automobile. Therefore, casting of 6016 was tried in this study.Castability and characteristics of roll cast 6016 strip were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. The 6016 could be cast at speed of 60 m/min. The thickness of the 6016 was 3 mm.The microstructure at as-cast and after T6 heat treatment was shown. The microstructure was very fine by theeffect of the rapid solidification. The mechanical properties were investigated by the tension test and 180 degreesbending test. The as-cast strip could be cold rolled down to 1 mm without homogenization. The result of tensiontest (gage length 50mm) of T4 strip was as below, tensile stress was 242 MPa, proof stress was 123 MPa andelongation was 26%. There was no crack at the outer surface of 180-degree-bent strip until contact. This showsthe strip endure the hem forming.Research limitations/implications: is the width of the strip was 100 mm. The test using a large scale twin rollcaster must be operated.Practical implications: are as below. The mechanical properties of the roll-cast 6016 were enough for the sheetmetal for the automobile. The low productivity of the twin roll caster could be improved, and economy 6016strip was able to produce.Originality/value: is that 6016 strip could be cast at speed 60 m/min and this strip had good mechanicalproperties.
High speed twin roll casting of 6016 aluminium alloy strip  [PDF]
H. Sakaguchi,T. Haga,H. Watari,S Kumai
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: of this paper is to clear the possibility of high speed roll casting of aluminum alloy strip. In the bodyof the automobiles, a sheet of 6016 aluminum alloy is adopted for the outer panel. Therefore, casting of 6016was tried in this study. Characteristics of roll cast 6016 were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. 6016 alloy could be cast into the strip continuously at the speed of 60m/min. Thethickness of the strip was 3.4 mm. The microstructure at as-cast and after T4 heat treatment was shown. Themicrostructure was very fine. The mechanical properties were investigated by the tensile test and 180 degreesvending test. The as-cast strip could be cold rolled without homogenization to 1mm. Result of tensile test wastensile strength was 230MPa, 0.2% proof stress was 118MPa and elongation was 33%. 6016 strip of T4 heattreatment could be bent 180 degrees without occurrence of crack at the outer surface or breaking.Research limitations/implications: is the width of the strip was 100 mm. It is necessary to test twin roll casterequipped wide rolls.Practical implications: are as below. The mechanical properties of the roll-cast 6016 were enough for the sheetmetal for the automobile. The low productivity of the twin roll caster could be improved.Originality/value: is that 6016 strip could be cast continuously at speed 60 m/min and this strip had goodmechanical properties.
Clad strip casting by a twin roll caster  [PDF]
T. Haga,R. Nakamura,S. Kumai,H. Watari
Archives of Materials Science and Engineering , 2009,
Abstract: Purpose: Of this paper is to realize the casting of the clad strip by only one process. Therefore, the investigation of the ability of the casting of the clad strip by a vertical type twin roll caster was operated. The aim of the use of the twin roll caster to make clad strip was in the reduction of the production-energy of the clad strip.Design/methodology/approach: Used in the present study was a vertical type twin roll caster with the scriber. The scriber was used to prevent the mixture of the two kinds of the melts. The scriber was set at roll-bite, and the scriber contacted to the one of solidification layer. The melt was stopped by the scriber and the only the solidification layer was dragged by the roll.Findings: The clad strip with the clear interface could be by the vertical type twin roll caster with the scriber. The scriber was useful to drag only the solid and semisolid layer. The two kinds of strips were connected strictly at the interface of the clad strip. The clad strip was not broken at the interface by the continuous bending.Research limitations/implications: Are that 100 mm width-strip was cast in the present study. Ability of the clad strip that is wider than 100 mm was not clear. The control of the clad ratio was not investigated.Practical implications: The twin roll caster devised and investigated in this report is useful to cast clad strip like the brazing sheet for the radiator of the automobile.Originality/value: The vertical type twin roll cater to cast clad strip is original process. The scriber was used to prevent the mixture of the two kinds of melts. The scriber was not used in the previous research to cast clad strip at the twin roll caster, and use of the scriber was the first try.
SIMULATION OF THE TWIN ROLL STAINLESS STRIP CASTING PROCESS
YC Miao,XM Zhang,GD Wang,
Y.C. Miao
,X.M. Zhang,G.D. Wang,H.S. Di and X.H. Liu

金属学报(英文版) , 2001,
Abstract: The position of the solidification completed temperature of twin roll stainless strip casting process is very important to the quality of the casting strip. In order to control this position, the .solidification completed temperature should be known at first. The present paper first. simulated dendritic microsegregation under conditions of twin roll stainless strip casting, and got the relationship between the temperature and solid fraction of the mush zone. The temperatures such as ZDT (equal to the solidifica- tion completed temperature and LIT (liquid impenetrable temperature), et al., also were obtained. Then by using the turbulent model, the flow and thermal fields of the pool of the twin roll stainless strip casting, and the speed and temperature fields oj different casting speeds were given cud also explained. The results are coincident with the experimental result. Combined with the results of these two simulations, the appropriated casting speed was found.
High speed twin roll casting of Al-3Si-0.6Mg strip  [PDF]
T. Haga,M. Ikawa,H.Watari,S.Kumai
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: Purpose of this paper is to clear the possibility of high speed roll casting of thin strip of Al-3%Si-0.6%Mg alloy. Investigation of the mechanical properties of the roll cast Al-3%Si-0.6%Mg strip was purpose, too.Design/methodology/approach: Method used in the present study was high speed twin roll caster and low temperature casting. These methods were used to realize rapid solidification, and increase of casting speed.Findings: Findings are that Al-3%Si-0.6%Mg was could be cast at speed of 60 m/min. This strip was 3.1 mm-thick. As cast strip could be cold-rolled down to sheet of 1 mm-thick. 180 degrees bending test was operated on the sheet after T4 heat treatment and crack was not occurred at the outer surface.Research limitations/implications: Research limitation is that the width of the strip was 100 mm and investigation of the properties was not enough for practical use. Wider strip must be cast using the twin roll caster of the size for production.Practical implications: Practical implications are as below. The economy sheet for the auto mobile can be produced by the high speed twin roll caster. Al-3%Si-0.6%Mg can be used both the casting and plastic forming. Therefore, fractionation in the recycle of the aluminum alloy will becomes easy. The content of Fe in the recycled aluminum alloy increases. Fe becomes intermetallic of AlSiFe. Si for Mg2Si becomes deficient. 3%Si was enough for Mg2Si if AlSiFe was precipitated. Al-3%Si-0.6%Mg is suitable for recycle.Originality/value: The result means the roll cast Al-3%Si-0.6%Mg has ability to be used as the body sheet of the auto mobile.
Twin roll casting of magnesium alloys with high aluminum contents  [PDF]
H. Watari,T. Haga,Y. Shibue,K. Davey
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The purpose of the work is to establish a manufacturing process and technology to facilitate theeconomical manufacture of high-quality magnesium sheet alloys with high aluminum contents, such as AZ61and AZ91. The aim of the work is to establish a twin roll casting technology to facilitate the manufacture ofAZ61 and AZ91 magnesium sheet alloys economically whilst maintaining high quality.Design/methodology/approach: A horizontal type twin roll caster was used to manufacture thin magnesium alloysheets of AZ61 and AZ91. Pair of copper alloy roll and pure copper roll was used for the horizontal type twin roll caster.A closed type tundish was set to the roll caster to keep stable contact of molten magnesium with upper and lower rolls.Findings: The experiment results clarified that AZ61 and AZ91 sheets can be manufactured by twin roll castingprocess. The product sheet thickness in the present experiment is 2.0 to 4.5 mm for AZ91, 2.5 to 5.0mm forAZ61. Mill stiffness and a method of predicting the cast sheet’s thickness were investigated to determine theappropriate manufacturing conditions. The microstructure of AZ61 cast strips was equiaxed structure and thecrystal sizes are different depending on cross section observed. The dendric and equiaxed microstructure wereseen in the microstructure of AZ91 cross section. The intermetllic Mg17Al12 was seen in the grain boundary inAZ91 when roll speed was very slow. The grain size of the manufactured wrought magnesium alloys sheet wasless than 10 micrometers. The obtained magnesium alloy sheet exhibited an equivalent limiting drawing ratio ina warm-drawing test. The limiting drawing ratio of AZ61 was 2.6 and 2.4 for AZ91.Research limitations/implications: The suitable roll speed was from 9m/min to 15m/min in manufacturingAZ91 and AZ61 strip using copper alloy rolls. When in use of pure copper roll, strips were cast between 6m/minand 20m/min for manufacturing AZ61 and AZ91. The superheats in the experiment were 15oC and 30oC. Thecast strips should be hot rolled at 300oC.Originality/value: value In this experiment, it is clarified that AZ61, AZ91 sheets can be manufactured by twinroll casting. These cast sheet can be hot rolled and the manufacturing process by twin roll casting enable tomanufacure thin magnesium sheet alloys with high aluminum contents. It has been found that the manufacturedcast AZ61 and AZ91 have good formability by a warm deep drawing test.
High speed twin roll casting of recycled Al-3Si-0.6Mg strip  [PDF]
T. Haga,M. Ikawa,H. Watari,S. Kumai
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: Purpose of this paper is to clear the possibility of high speed roll casting of thin strip of recycled Al-3%Si-0.6%Mg alloy. Investigation of the mechanical properties of the roll cast recycled Al-3%Si-0.6%Mg strip was purpose, too.Design/methodology/approach: Method used in the present study was high speed twin roll caster and low temperature casting. These methods were used to realize rapid solidification, and increase of casting speed.Findings: Findings are that recycled Al-3%Si-0.6%Mg was could be cast at speed of 60 m/min. This strip was 3.1 mm-thick. As cast strip could be cold-rolled down to sheet of 1 mm-thick. 180 degrees bending test was operated on the sheet after T4 heat treatment and crack was not occurred at the outer surface. This result means the roll cast recycled Al-3%Si-0.6%Mg can be used as the body of the auto mobile.Research limitations/implications: Research limitation is that the width of the strip was 100 mm and investigation of the properties was not enough for practical use. Wider strip must be cast using the twin roll caster of the size for production.Practical implications: Practical implications are as below. The economy sheet for the auto mobile can be produced by the high speed twin roll caster. Al-3%Si-0.6%Mg can be used both the casting and plastic forming. Therefore, fractionation in the recycle of the aluminum alloy will becomes easy. The content of Fe in the recycled aluminum alloy increases. Fe becomes intermetallic of AlSiFe. Si for Mg2Si becomes deficient. 3%Si was enough for Mg2Si if AlSiFe was precipitated. Al-3%Si-0.6%Mg is suitable for recycle.Originality/value: The economy sheet of Al-3%Si-0.6%Mg can be made by the high productivity of the HSTRC. The result of this report contributes to make the economy aluminum alloy sheet for the automobile.
Texture analysis of cold rolled and annealed aluminum alloy produced by twin-roll casting
Martins, Juliana de Paula;Carvalho, André Luis Moreira de;Padilha, Angelo Fernando;
Materials Research , 2012, DOI: 10.1590/S1516-14392011005000101
Abstract: a 7.4 mm thick strip of 3003 aluminum alloy produced by the industrial twin-roll casting (trc) process was homogenized at 500 °c for 12 hours, after which it was cold rolled in two conditions: 1) to reduce the strip's thickness by 67%, and 2) to reduce it by 91%. the alloy was annealed at 400 °c for 1 hour in both conditions. the results revealed that a rotated cube texture, the {001}<110> component, predominated in the as-cast condition and was transformed into brass, copper and s type textures during the cold rolling process. there was practically no difference between the deformation textures at the two thickness reductions.
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