A Comparison of Deep Drawing and Ironing of Metal Alloy Strip Produced Conventionally and Non-Conventionally via Semi Solid Material Processing

Abstract

A semi solid thin strip continuous casting process was used to obtain 50%wt Pb/50%wtSn strip by single and twin roll processing at speed of 15 m/min. A 50%wt Pb/50%wtSn plate ingot was also cast for rolling conventionally into strips of 1.4 mm thickness and 45 mm width for comparison with those achieved non-conventionally. This hypoeutectic alloy has a solidification interval and fusion temperature of approximately 31°C and 215°C respectively. The casting alloy temperature was around 280°C as measured by a type K immersion thermocouple prior to pouring into a tundish designed to maintain a constant melt flow on the cooling slope during semi solid material production. A nozzle with a weir ensures that the semi solid material is dragged smoothly by the lower roll, producing strip with minimum contamination of slag/oxide. The temperatures of the cooling slope and the lower roll were also monitored using K type thermocouples. The coiled semi solid strip, which has a thickness of 1.5 mm and 45 mm width, was rolled conventionally in order to obtain 1.2 mm thick strip. The coiled thixorolled strip had a thickness of 1.2 mm and achieved practically the same width as the conventional strips. Blanks of 40 mm diameter were cut from the strips in a mechanical press, ready for deep drawing and ironing for mechanical characterization. All the strips achieved from non-conventional processing had the same mechanical performance as those achieved conventionally. The limiting drawing ratio (LDR) achieved was approximately 2.0 for all strips. Microscopy examination was made in order to observe phase segregation during processing.

Recycling Al-Si Alloy by Semisolid Material Dragged during Continuous-Casting Strip Processing

“…Examples of the absence of hot cracks were found in the Al-Si alloys during the casting of strips with a composition of 11.3% wt Si closest to the eutectic point [9], as well as in other quasi eutectic alloys such as Sn-50%Pb-50% [14]. This suggests that, in this work, the hot cracks formed were due to contamination by Sn and Pb in the Al-Si alloys.…”

Continuous Production of a Multi-Filament Reinforced Metal Matrix Composite Strip from the Semisolid State

“…The gap was adjusted to produce a metal matrix composite strip of approximately 1.4 mm in thickness. The roll speed was set to 15 m/min because it has been previously shown to produce the best results [3,5]. The rolls are made of mild steel of 105 mm and 101 mm diameter and length, respectively.…”

“…The upper roll thixoforges the semisolid material, which is transported by the chill shell that nucleated on the lower roll. The semisolid SnPb eutectic alloy was chosen as a metallic matrix for its promotion of the formation of a continuous strip, its easily identifiable phase and its manipulability for experimental study [5]. The sequences required to perform the experimental procedure in this work are shown.…”

Fabricação De Tiras Metálicas Contínuas Diretamente Do Estado Líquido Reforçada Por

“…Este laminador foi modificado e tem sido utilizado para obter tiras metálicas fundidas e tixolaminadas para obtenção de tiras metálicas compósitas diretamente do estado líquido passando para o estado semi-sólido na calha de resfriamento. (11)(12)(13)(14)…”

“…A temperatura empregada é em torno de 50ºC acima da temperatura líquidus (212ºC) para obter uma fluidez suficiente para a operação de vazamento, verificada em testes anteriores. (11)(12)(13)(14) Através de um sistema de aquisição de sinais e dados o qual é formado por uma interface (Pico TC-08 IMPAC) e um software Pico-Log, foi possível obter o perfil de temperatura ao longo do tempo.…”