Melt Conditioning Twin Roll Casting with Thermo-Mechanical Treatment of Recycled AA6111 Alloy

Abstract

A high shear melt conditioning twin roll casting process with thermo-mechanical treatment was tested to increase the tolerance to high impurity levels in recycled aluminium alloy. Applying high shear melt conditioning prior to casting of recycled AA6111 alloy exhibits reduced centre-line segregation and a fine equiaxed grain structure with improved sheet quality. Homogenisation at 540°C for 8 h with annealing at 520°C for 10 min of the melt-conditioned twin roll casting strip (MC-TRC) showed a clear grain recrystallisation, which was better than the conventional twin roll casting TRC strip. The mechanical test showed a significant improvement in the hardness after applying high shear melt conditioning with thermo-mechanical treatment.

Fe-Rich Intermetallic Formation and Mechanical Properties of Recycled AA6111 Alloy Strips Produced by Melt Conditioning Twin Roll Casting

“…1; the detailed description of this caster was reported in our previous publications. 7,8 A high shear melt conditioning chamber with a tundish assembly was used to process the recycled aluminium alloy prior to casting into the rolls. The details of the melt feeding chamber assembly with the shearing device have been described in a previous publication 9 and are shown in the schematic drawing in Fig.…”

“…6 To minimize these defects in casting recycled aluminium alloys and improve the quality of the strip, a new technique was tested by using high shear melt conditioning before casting, and the developed process is known as melt conditioning twin roll casting (MC-TRC). [7][8][9] In this newly developed technology, a rotor-stator mixer was used to apply intensive melt shearing. This rotor-stator type technology has been tested as a multi-purpose device for degassing, grain refinement, metal matrix composite casting and industrial casting processes such as direct chill casting and twin roll casting.…”

“…11 In our previous study, we found that by applying HSMC in the casting of AA6111 strips the segregation of intermetallics to the centreline was eliminated with significant improvement in the microstructure and strip quality. 8 In our previous publication, 8 we investigated the effect of high shear melt conditioning on the microstructure of recycled AA6111 alloy and the possibility of reducing casting defects such as centreline segregation in casting recycled aluminium alloys in twin roll casting. In this study, we investigated the impact of HSMC on the size and distribution of Fe-rich intermetallic compounds within the recycled AA6111 strips formed by the twin roll casting process and in addition reported the measured mechanical properties of TRC and MC-TRC processed strips.…”

Microstructures and Macrosegregation of Al–Zn–Mg–Cu Alloy Billet Prepared by Uniform Direct Chill Casting

“…Recently, many researchers have studied the application of external force including mechanical stirring, ultrasonic vibrating and electromagnetic stirring on DC casting to improve the uniformity of the temperature field of billets and to obtain high quality billets with fine and uniform structures [13][14][15][16]. Electromagnetic stirring (EMS) is the most widely used melt treatment technology in industry and is widely used in the field of steel and non-ferrous metal continuous casting [17,18].…”

Melt Conditioned Direct Chill (MC-DC) Casting and Extrusion of AA5754 Aluminium Alloy Formulated from Recycled Taint Tabor Scrap

“…Due to its deep drawing characteristics, it is used in structural panels as an alternative to a mild steel sheet. In addition, AA5754 alloy has excellent corrosion resistance and it is an alloy suitable for recycling [2,3]. In collaboration between Novelis UK and Jaguar Land Rover, a new automotive product RC5754 alloy has been developed.…”