Papers by Keyword: Strip Casting

Abstract: Continuous strip metal matrix composite (MMC) casting of 0.3 mm diameter hard-drawn stainless steel (316L) wire in a quasi-eutectic SnPb (64Sn36Pb) matrix was performed by a two-roll melt drag processing (TRMDping) method, with the wire being dragged through a semisolid puddle with a fibre contact time of approximately 0.2 s. A slag weir placed at the nozzle contained two wire guide holes: one located near the upper roll, and the other located between the rolls. A successful continuous composite strip casting with good fibre alignment was achieved by inserting and embedding the wire into the matrix using the guide hole between the rolls. Degeneration of eutectic/dendrite structures led to the formation of globular structures. The occurrence and formation mechanisms of cracks, de-lamination and voids in the matrix were discussed. TRMDping is economically viable and has significant benefits over other MMC fabrication methods.

Abstract: The processing equipment for near-net shape technology of materials is introduced in the paper. According to analysis of industrialized processing equipment and technology testing equipment for difficult-to-cut alloy materials, combined with difficulties in strip casting and features of difficult-to-cut alloy materials, the processing equipment for difficult-to-cut alloy materials near-net shaping is developed, thus realized single machine-shaping from molten steel to cold rolling product, and improved near-net shape manufacturing technology of materials.

Abstract: A scraper was developed and attached to the single roll caster in order to improve the free solidified surface of as-cast strip cast. Semisolid metal on the free solidified surface was flattened by the scraper and the surface became flat. The AA5182 aluminum alloy could be cast at speeds up to 40m/min. Thickness was about 3mm. Pressure of the unit width of the scraper was ranging from 0.1N/mm to 1.0N/mm, and these pressure was enough to make the free solidified surface flat. Center line segregation did not occur as the strip was solidified from single side at the strip cast by the single roll caster. Roll-cast strip could be cold rolled down to 1mm. There was not difference between the roll contact surface and the free solidified surface of the strip after cold rolling judging by a visual examination. Result of tension test of the roll cast and cold rolled strip was as same as that of D.C. cast and rolled strip. Deep drawing test was operated at the conditions both of the roll contact surface and the free solidified surface were outer side. LDR (limited drawing ratio) was same at both conditions and they were 1.8. Thickness of the strip was controlled by the roll speed, solidification length (length of the melt pool) and pressure of the scraper. The single roll caster is simpler than a twin roll caster. Rigidity for rolling was not required for the single roll caster. Cost of the roll is half comparing a twin roll caster. The equipment cost of the single roll caster is more economy than that of the twin roll caster.

Abstract: Using nonlinear finite element method, the changes of roll temperature and hot roll profile are studied in the initial casting stage, and the changing rule of hot roll profile is described in the initial casting stage which can be the evidence to decide the initial roll profile and casting process.

Abstract: A single roll caster equipped with a scraper was devised to cast the strip with sound free solidified surface. A property of this single caster is equipment of the scraper. Semisolid metal on the free solidified surface was scribed by a scraper and the surface became flat. Center line segregation did not occur as the strip was solidified from single side. The AA5182 aluminum alloy could be cast at speeds up to 40m/min. Thickness was about 3mm. Pressure of the unit width from the scraper was ranging from 0.1N/mm to 1.0N/mm, and these pressure was enough to make the free solidified surface flat. Roll cast strip could be cold rolled down to 1mm. There was not difference between roll contact surface and the free solidified surface after cold rolling by a visual examination. Result of tension test of the roll cast strip was as same as that of D.C. cast and rolled strip. Deep drawing test was operated at the conditions both of the roll contact surface and the free solidified surface was outside. LDR (limited drawing ratio) was same at both conditions and they were 1.8. Thickness of the strip was controlled by the roll speed, solidification length (length of the melt pool) and pressure of the scraper. The single roll caster is simpler than a twin roll caster. Rigidity for rolling was not needed for the single roll caster. Cost of the roll is half comparing a twin roll caster. The equipment cost of the single roll caster is more economy than that of the twin roll caster.

Abstract: Microstructural evolutions of Al-33wt. % Cu alloy strip, prepared by twin roll strip casting (TRC) at different roll speed (100-500 rpm) were studied in the present investigation. The as cast sample were subjected to Scanning Electron Microscope (SEM) to study the effect of rolling speed on microstructure along the thickness of the strip. The microstructure shows that Al-33 wt. % Cu strip is a layered structure which consists of partly lamellar and wavy structure. The lamellar microstructure consists of alternating layers of well bonded α-Al phase and θ-Al₂Cu phase.

Abstract: Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000mm and the diameter of the upper roll (small roll) was 250mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5μm. The as-cast strip was ranging from 2mm to 3mm thick and its width was 100mm. The as-cast strip could be hot rolled down to 1mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

Abstract: Roll caster to cast a three layers clad strip was invented and effect of casting conditions on the clad strip was investigated. Two vertical type twin roll casters were set at vertically tandem position to cast three layers clad strip. Roll speed, roll load (separating force), melt temperature and elements of the aluminum alloy were chosen as the experimental conditions to be investigated. The roll load (separating force) and elements of aluminum alloy were important factors to cast sound clad strip. The clad strip could be cast at the speeds up to 40m/min. Interface between the strips were clear and elements of each strip did not diffuse to other strip. The clad strip was not peeled off at the interfaces by continuous bending. Strips were strictly connected at the interfaces.

Abstract: An Fe-6.2wt%Si as-cast strip with equiaxed grains and obvious {001} fiber texture was produced by twin-roll strip casting process. The as-cast strip was successively performed by hot rolling, warm rolling and annealing. The microstructure and texture evolution at each process stage were investigated by using electron backscatter diffraction and x-ray diffraction. It was found that the finally annealed sheet was characterized by large grain size, mild γ-fiber texture and obvious {001} fiber texture. Therefore, a high magnetic induction and a low core loss were obtained in the sheet.

Abstract: Single roll caster to cast strip with sound free solidified surface was invented. A scraper was attached to the single roll caster to improve the free solidified surface. AA5182 and AA6022 strips were cast using the single roll caster equipped with the scraper. Mechanical properties of the strip were investigated by tension test, bending test and deep drawing. Mechanical properties of the strip cast by the single roll caster were as same as those made by DC casting.