Roll Casting of Al-SiCp Strip

2010 ◽  
Vol 654-656 ◽  
pp. 978-981 ◽  
Author(s):  
Ryoji Nakamura ◽  
Teppei Nakamura ◽  
Sinji Kumi ◽  
Hisaki Watari

Al-SiCp aluminum alloy has some useful advantages i.e., low thermal expansion, better thermal conductivity and wear resistant. Recently, plates of Al-SiCp with thickness less than 1mm was demanded. The Al-SiCp is hard and brittle. Therefore, only hot rolling was a useful process to make thin plate. In the present study, roll casting of Al-SiCp strip was tried by a vertical type high speed twin roll caster to evaluate energy savings. The Al-SiCp strip, with thickness about 2mm, was cast directly from the molten metal. The particles of SiC were dispersed uniformly. The as-cast Al-SiCp could be coiled. The roll cast Al-SiCp had superior ductility. For this reason, the eutectic Si in matrix aluminum alloy (Al-Si alloy) became fine and globular. Cold rolling could be operated after 1-pass of hot rolling. The 1mm-thick Al-SiCp plate could be made by one-pass of hot rolling and 3-passes of cold rolling and annealing from as-cast strip.

2010 ◽  
Vol 139-141 ◽  
pp. 477-480
Author(s):  
Ryoji Nakamura ◽  
Shuya Hanada ◽  
Shinji Kumai ◽  
Hisaki Watari

An inline hot rolling was operated on 5182 aluminum alloy strip cast using a vertical type high speed caster (VHSTRC) at the speed of 60 m/min. A porosity existing at center line of the thickness and a ripple mark on the surface, these are typical defects of the strip cast by the VHSTRC, could be improved by the inline rolling. The rolling speed was as same as the roll-casting-speed of 60m/min. The temperature of the strip, when the inline rolling was operated, was 450oC. The reduction of the strip of the inline rolling was 35%.


2010 ◽  
Vol 154-155 ◽  
pp. 1544-1548 ◽  
Author(s):  
Kosuke Komeda ◽  
Ryoji Nakamura ◽  
Shinji Kumai

The disadvantages of the conventional twin-roll caster for aluminum alloy are low casting speeds and limited choices of alloys that are castable by this processing. It is known that strip casting of aluminum alloy 5182 is very difficult because of their wider freezing zones. The vertical-type high-speed twin-roll caster used in the present study was devised to overcome these disadvantages. Features of the high speed twin roll casters are as below. Mild steel rolls were used in order to increase the casting speed and to be made at a lower equipment cost. Roll coating is produced in casting of Al-Mg alloy. Therefore lubricant, that resists heat transfer, was not used in the present study. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated. The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a deep drawing test.


2011 ◽  
Vol 675-677 ◽  
pp. 811-814 ◽  
Author(s):  
Toshio Haga ◽  
Teppei Nakamura ◽  
S. Kumai ◽  
H. Watari

The strip casting of Al-SiCp alloy was operated by a high speed twin roll caster. The content of SiCp was 20Vol% and 30Vol%. Both of Al-20Vol%SiCp and Al-30Vol%SiCp strips could be cast continuously at the speed up to 90m/min. The SiCp particle distributed uniformly. This was the effect of fine grain of the strip. The as-cast strip of Al-20Vol%SiCp could be cold rolled after homogenization. The as-cast strip of Al-30Vol%SiCp could be cold rolled after once hot rolling and annealing. The as-cast strip of Al-20Vol%SiCp could be coiled at the diameter of 460mm.


2010 ◽  
Vol 139-141 ◽  
pp. 481-484
Author(s):  
Ryoji Nakamura ◽  
Teppei Nakamura ◽  
Ryoji Nakamura ◽  
Hideto Harada ◽  
Shinji Kumai ◽  
...  

Roll casting of Al-SiCp composite alloy strip was tried using a vertical type high speed twin roll caster equipped with mild steel rolls. The Al-20vol% SiCp and Al-30vol%SiCp alloy could be roll-cast to the strip. The casting speed was 30m/min. The thickness of as-cast strip was thinner than 2.5mm. The SiCp powder was dispersed uniformly at the thickness direction. The as-cast strip could be thin down to 1mm by the hot rolling and the cold rolling without broken.


2005 ◽  
Vol 46 (12) ◽  
pp. 2596-2601 ◽  
Author(s):  
Toshio Haga ◽  
Masaaki Ikawa ◽  
Hisaki Watari ◽  
Kenta Suzuki ◽  
Shinji Kumai

2016 ◽  
Vol 877 ◽  
pp. 51-55 ◽  
Author(s):  
Ram Song ◽  
Yohei Harada ◽  
Shinji Muraishi ◽  
Shinji Kumai

For decades, twin-roll casting has been applied for manufacturing aluminum alloy sheets. This conventional process contributes to make thin aluminum sheets from the molten metal directly. Recently, vertical-type high-speed twin-roll casting (HSTRC) has been developed with much higher casting speed rather than the horizontal-type. Some modifications such as feeding nozzle and water-cooling system of copper rolls contribute to increase cooling rates. This characteristic leads to many metallurgical advantages like grain refinement, super-saturation of alloying elements and fine distribution of secondary particles. The objective of this study is to investigate the constituent particles in HSTRC aluminum alloy. The commercial Al-Mn alloy strip was successfully fabricated by HSTRC. Clearly different microstructure was found in thickness direction. Many constituent particles observed along the grain boundaries/cell boundaries as well as inside of Al matrix on the surface area, while eutectic structure around globular grain boundaries was observed in mid-central area. The morphology as well as chemical compositions of the constituent particles were investigated.


2016 ◽  
Vol 877 ◽  
pp. 56-61 ◽  
Author(s):  
Shinji Kumai ◽  
Yusuke Takayama ◽  
Ryoji Nakamura ◽  
Daisuke Shimosaka ◽  
Yohei Harada ◽  
...  

A horizontal-type twin roll casting method has been popular for producing aluminum alloy strips, however, it is characterized by a relatively low productivity (1~6 m/min). In contrast, a vertical-type high-speed twin-roll casting method possesses an extremely high productivity (60~120 m/min (1~2 m/s)) and an excellent heat extraction ability. The rapid cooling effect provided significant microstructure refinement and mechanical properties improvement in various kinds of cast aluminum alloy products. Not only “product to product recycling” but also “up-grade recycling” can be achieved by making good use of these merits. Two examples of application showing the potential of vertical-type high-speed twin roll casting method are presented. (1) Several kinds of Al-Si base alloy were cast into the strips. Not only strength and toughness but also formability was increased in the twin roll cast products. In particular, great improvement in deformability shows the potential of the twin-roll cast aluminum alloy products as substitutes for some wrought aluminum alloy products. (2) The vertical-type tandem twin-roll caster was able to fabricate a clad strip by single step. The A4045/A3003/A4045 aluminum alloy clad sheets produced by the twin-roll casting showed better mechanical properties than the conventional hot-roll bonded clad sheets.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 520
Author(s):  
Toshio Haga

Two types of high-speed twin-roll casters and a single-roll caster equipped with a scraper were proposed. One of the twin-roll casters is a vertical-type high-speed twin-roll caster, and the other twin-roll caster is an unequal-diameter twin-roll caster. The vertical-type high-speed twin-roll caster can cast strip at speeds of up to 120 m/min. The unequal-diameter twin-roll caster casts strip at speeds up to 60 m/min. The unequal-diameter twin-roll caster is superior to the vertical-type high-speed twin-roll caster at the point of conveyance of the cast strip. A single-roll caster equipped with a scraper can cast strip without center-line segregation at speeds of up to 40 m/min. The use of a copper alloy roll and the non-use of a parting material enable high-speed roll casting. Since the roll loads of these casters are smaller than 0.1 kN/mm, soft copper alloy roll can be used. The strip does not stick to the roll without the parting material because of the use of the copper alloy roll with high thermal conductivity and the small roll load. The cooling rate near the surface is higher than 2000 °C/s.


2011 ◽  
Vol 121-126 ◽  
pp. 4667-4670
Author(s):  
Toshio Haga ◽  
Kosuke Komeda ◽  
Kenta Mtsuoka ◽  
Shinji Kumai ◽  
Hisaki Watari

Roll casting of the model alloy of recycled AA5182 aluminum alloy was investigated. Fe up to 0.6% was added to the AA5182 to make the model alloys of recycled AA5182. Increase of 0.6% of Fe means that the recycle was three times operated. A vertical type high speed twin roll caster was used. Some devices were operated on the twin roll caster to increase the cooling rate in order to make impurity fine. The roll speed could be increased up to 80m/min. The roll-castability did not become worse by the addition of the Fe. The LDR (limiting Drawing Ratio) was 1.9 when the Fe addition was 0.6. The deterioration of the mechanical properties by the addition of impurity Fe was very small.


2010 ◽  
Vol 443 ◽  
pp. 128-133 ◽  
Author(s):  
Ryoji Nakamura ◽  
Masakazu Sawai ◽  
Ryoji Nakamura ◽  
Takanori Yamabayashi ◽  
Shinji Kumai ◽  
...  

A roll caster, which could cast the three layers of clad strip directly from the molten metal, was designed, assembled and tested. The base strip was AA3003 aluminum alloy and overlay strips were AA4045 aluminum alloy. An unequal diameter twin roll caster was modified to cast clad strip. Two small rolls were amounted on a large roll. A scraper plate was used to prevent the mixture of the different kinds of melts. The casting of three strips and the connecting of strips could be operated by one roll caster. The interfaces between the strips were clear, and the mixture of the melt did not occur. The clad strip could be cold rolled without the annealing. The clad strip did not peel at connecting surface by the cold rolling and continuous bending. The strips were connected strictly. The casting speed was 20m/min, and this speed was much higher than the casting speed of the conventional twin roll caster for aluminum alloys.


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