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1

Casting of aluminium alloy strip using an unequal diameter twin roll caster

Haga T., Inui H., Watari H., Kumai S.

Archives of Materials Science and Engineering

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2008

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Vol. 29, nr 2

113-116

EN

Purpose: of this paper is to clear the property and ability of an unequal diameter twin roll caster to cast commercial size strip. Therefore, 400mm-width strip was cast as first step. Surface-condition, microstructure and mechanical 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 was about 4 mm-thick. There were some defects on the surface. As cast strip could be cold-rolled down to sheet of 1 mm-thick. 180 degrees bending test was operated on the 6022 sheet after T4 heat treatment. Crack did not occurred 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 the properties 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 twin roll 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 twin roll caster. 3083, 5182 and 6022 can be cast at the speed of 20m/min. The thickness of the strip was about 4mm.

2

High speed twin roll casting of Al-3Si-0.6Mg strip

Haga T., Ikawa M., Watari H., Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

337--340

EN

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.

3

High speed twin roll casting of 6016 strip

Haga T., Ikawa M., Watari H., Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

371--374

EN

Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016 aluminum 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 designed to 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 the effect of the rapid solidification. The mechanical properties were investigated by the tension test and 180 degrees bending test. The as-cast strip could be cold rolled down to 1 mm without homogenization. The result of tension test (gage length 50mm) of T4 strip was as below, tensile stress was 242 MPa, proof stress was 123 MPa and elongation was 26%. There was no crack at the outer surface of 180-degree-bent strip until contact. This shows the strip endure the hem forming. Research limitations/implications: is the width of the strip was 100 mm. The test using a large scale twin roll caster must be operated. Practical implications: are as below. The mechanical properties of the roll-cast 6016 were enough for the sheet metal for the automobile. The low productivity of the twin roll caster could be improved, and economy 6016 strip was able to produce. Originality/value: is that 6016 strip could be cast at speed 60 m/min and this strip had good mechanical properties.

4

High speed roll casting of Mg alloy strip by a vertical type twin roll caster

Haga T., Watari H., Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 15, nr 1-2

186--192

EN

Purpose: The possibility of high speed roll casting of AZ31, AM60 and AZ91 was investigated. Warm deep drawing of roll cast magnesium alloy was operated. and formability of roll cast magnesium strip was cleared. Design/methodology/approach: A vertical type high speed twin roll caster was used. The roll casting was operated in the air atmosphere. The casting speed was from 60 m/min up to 180 m/min. Low temperature casting was adopted to realize high speed casting. Findings: Strip thinner 3 mm with 100 width could be cast continuously. The casting ability became better with increasing content of Al. Roll cast Mg alloy strips could be hot-rolled down to 0.5 mm. AZ31 as-cast strip could be thinner down to 0.5 mm only by three times of hot rolling. Deep drawing was operated with three kinds of Mg alloy at 250°C, and LDR value was larger than 2.0. It was shown that deep drawing of AZ91 alloy for casting was possible. Research limitations/implications: There was tendency that cracks occurred at the center in the thickness direction as Al content increased. Practical implications: Sheet metal forming of magnesium alloy with high content Al can be realized. Originality/value: It was shown that possibility of high speed roll casting of magnesium alloy, and warm deep drawing of roll cast AZ91 strip.

5

Problem utleniania ciekłego stopu cynku z miedzią i tytanem podczas odlewania taśmy metodą ciągłą.

Wesołowski J., Ciura L., Kazana W.

Rudy i Metale Nieżelazne

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2001

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R. 46, nr 1

3-6

PL

Przedstawiono wyniki przeprowadzonych badań dotyczących zjawiska okresowego występowania dużej intensywności utleniania stopu cynk-miedź-tytan w warunkach odlewania z tego stopu taśmy metodą ciągłą. Ustalono skład chemiczny fazy niemetalicznej dobrze zwilżonej przez fazę metaliczną stopu. Określono prawdopodobne przyczyny nasilonego utleniania ciekłego stopu na drodze jego transportu do maszyny odlewniczej.

EN

Investigation results of the phenomenon of periodical, great oxidation intensity of the zinc-copper-titanium alloy, at continuous strip casting of that alloy, are presented. The chemical composition of the non-metallic phase of the alloy was determined. The probable cause of the intensified oxidation of the molten alloy, during its transport to the casting machine, has been defined.

6

Computer simulation of fluid flow and heat transfer in strip casting of aluminum alloys

Kuznetsov A. V.

Applied Mechanics and Engineering

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1998

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Vol. 3, no 3

479-490

EN

In this study, results of numerical analysis of the continuous casting process aimed for a production of thin aluminum-copper strips are reported. A characteristic feature of the continuous casting process considered in this paper is a strong forced convection of liquid alloy caused by a changing height of a free surface. Computations are performed for Al-4.5 wt pct Cu alloy. In this investigation, heat transfer process is coupled with the fluid flow which occurs in the liquid metal and in the mushy zone. It is shown that there is an essential forced convection flow in the upper part of mushy zone between the position where the liquidus line reaches the free surface and the position where the height of the free surface reaches its maximum. This flow can cause a destruction of the dendritic structure which in its turn can be one of the reasons for instability of the process.