ICME 2023: Linkages: Processing I
Program Organizers: Charles Ward, AFRL/RXM; Heather Murdoch, U.S. Army Research Laboratory
Tuesday 3:00 PM
May 23, 2023
Room: Boca I-III
Location: Caribe Royale
Session Chair: Victoria Miller, University of Florida
3:00 PM
Modeling Defect Generation During Production of Single Crystal Sapphire: Peter Raninger1; Masoud Sistaninia1; Werner Eßl1; Georg Reiss1; Sina Lohrasbi2; Christoph Gammer3; 1Materials Center Leoben Forschung GmbH; 2FAMETEC GmbH; 3Erich Schmid Institute of Materials Science, Austrian Academy of Sciences
Single crystal sapphire can serve as substrate in electronic applications like µ-LEDs for next generation high-resolution displays. The manufacturing process includes directed solidification and cooling to room temperature, where stresses occur in the solid structure. Depending on the process parameters these stresses may lead to the generation of dislocations in one or more slip planes and cause a visible pattern in certain regions of the boule. The underlying mechanisms and the impact on the quality of the produced wafers are not yet fully understood. This work aims at the development of a material model, based on crystal plasticity theory that will be presented and applied for a simplified test case of crystal solidification and cooling. The model describes the onset and evolution of two densities corresponding to mobile and immobile dislocations and is capable to show the interconnection between the formation of dislocation patterns and remaining residual stresses after production.
3:20 PM
Study of the Critical Angle for Nucleation of Different Shape of Nanoparticles in an Aluminium Alloy: Ane Jimenez1; Mario Alfredo Renderos2; Eva Anglada1; Franck Girot2; Maider Garcia de Cortazar1; 1TECNALIA, Basque Research and Technology Alliance (BRTA); 2University of the Basque Country (UPV/EHU)
In the recent years the study of the nucleation due to the introduction of different shape and size nanoparticles in aluminium alloys have been studied. The critical angle needed for nucleation is going to be calculate for cubic, and pyramidal nanoparticles. Due to the complexity of the nucleation process, the wettability angle between the melted aluminium and the introduced reinforced nanoparticles was assumed to be constant. The use of this critical angle is proposed as a way of quantifying the nucleation feasibility for a specific nanoparticle geometry. Considering the theoretical calculations, a MATLAB® code has been developed to understand how the particle is going to be absorbed by the growing nucleus. In case of pyramidal particles 60o is the unique possible case of nucleating angle. For cubicand spherical nanoparticles the complete study of the available range is going to be defined in the present work.
3:40 PM
Cellular Automaton Simulation of Microstructure and Porosity Formation During Solidification Processing of Aluminum Alloys: Michael Moodispaw1; Buwei Chen1; Nicole Trometer1; Alan Luo1; 1Ohio State University
Simulation of microstructure and hydrogen-induced porosity formed during solidification of aluminum-based alloys is a critical link in integrated computational materials engineering (ICME) design and manufacturing of solidification products such as castings, welds or additively manufactured components. A three-dimensional cellular automaton (CA) model has been developed to predict the formation and evolution hydrogen porosity coupled with grain growth during solidification of a ternary Al-Si-Mg alloy. The simulation results fully describe the concurrent nucleation and evolution of both solidification grain structure and hydrogen porosity, yielding the morphology of multiple grains as well as the porosity size and distribution. This model has been applied and validated in gravity and high pressure die casting, laser welding and laser powder bed fusion additive manufacturing processes. These grain structure and porosity models have been validated by X-ray micro computed tomography (micro-CT), scanning electron microscopy (SEM) and optical metallography.