Cast Shop Technology: Poster Session
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Johannes Morscheiser, Novelis Koblenz GmbH
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
F-31: Effect of Electromagnetic Stirring on Morphology of α-Al Phase in Near Eutectic Al-Si Alloy: Yuichiro Murakami1; Kazutaka Suzuki1; Isao Matsui1; Naoki Omura1; 1National Institute of Advanced Industrial Science and Technology
By using fractional crystallization method, which is a method of refining substances based on differences in solubility, the primary α-Al phase with low Si contained can be obtained, therefore the aluminum scrap can be recycled. But in the near eutectic composition Al-Si alloy, such as alloy for high pressure die casting (HPDC), few primary α-Al phases can be crystallized. In this study, the electromagnetic stirring (EMS) was applied during the solidification of JIS ADC12 near eutectic Al-Si alloy which is widely used in HPDC, and the effect of EMS the amount of primary α-Al phase was investigated. In the result, the amount of primary α-Al phases is increased by applying EMS at solidification, and which is increased with increasing frequency.
F-32: Furnace Lining Degradation by 5xxx Aluminum Alloys: Athanasia Flampouri1; Theofani Tzevelekou1; Sofia Papadopoulou1; Spyros Pinis2; Nikolaos Sgourdakis2; 1ELKEME S.A.; 2ElvalHalcor S.A.
In the secondary aluminum industry the degradation of the melting furnaces lining in service has a significant impact on the energy efficiency and productivity affecting overall cast-house operational costs. The refractory degradation may involve metal penetration into the refractories, corundum formation at the metal-refractory interface, refractory discoloration and/or cracking. The objective of this work is to examine the corrosion performance of different types of commercial refractory raw materials, pre-cast silica based and alumina-silicate bricks, during melting of high Mg aluminum alloys. The results of lab-scale partial immersion melting trials are comparatively presented. The employed assessment techniques consist of macro-scopic and microscopic examination of interacted metal-ceramic surfaces, mineralogical characterization (XRD) of the refractories and chemical analysis of the treated metal. Microanalyses (SEM-EDS) of the critical involved interfaces enlighten the prevailing corrosion mechanisms. The described experimental work provides a simple tool to assist refractory lining selection in the aluminum treatment furnaces.
F-33: Microsegregation Mechanisms in Aluminum Binary Alloys of Different Casting Techniques: a Quantitative study: Zhenjie Yao1; Yang Huo2; Mei Li2; John Allison1; 1University of Michigan; 2Ford Motor Company
Understanding the microsegregation during the solidification process is important. Partition coefficient describes the microsegregation behavior, and it can also be directly used to calculate the microstructural quantities. In this poster, several mechanisms that happen at different solidification rates will be quantitatively studied. The partition coefficient will deviate from its equilibrium value during a non-equilibrium solidification; however, no systematic method is available to predict this value at different solidification rates and very limited data can be found to verify the models. In this study, the rate-dependent partition coefficient is calculated from EPMA measurements, which are statistically meaningful and more accurate. In addition, the study will also focus on using different physics-based analytical methods, verified by the experimental data, to predict the microsegregation behaviors over a large solidification rate range. This study will provide a quantitative prediction capability to reveal the of microsegregation in different casting techniques for different Al binary alloys.
F-34: Numerical Simulation of Temperature Field in 6061 Aluminum Alloy Vertical Twin-roll Casting Process: Chaopan Xie1; Xiaoping Liang1; Yu Wang1; 1ChongQing University
Due to the lightweight production technology of automobiles, aluminum alloys have advantages over steel, and a better understanding of the temperature distribution and freezing point position during the casting process is very important for producing high quality aluminum strips.In this paper, the enthalpy- porosity solidification model of ANSYS FLUENT software was used to establish a two-dimensional mathematical model of the two-roll casting and rolling zone of 6061 aluminum alloy, and the flow, heat transfer and solidification in the molten pool were simulated.Different casting parameters (casting speed, cooling strength and pouring temperature) were simulated and calculated. Analyze the influence of different process conditions on the degree of temperature field distribution and the location of freezing point, and determine the reasonable range of process parameters under high-speed casting conditions. Numerical calculations using existing models provide guidance for 6061 aluminum alloy twin roll casting.