Dr. Marcial Gonzalez, Assistant Professor , School of Mechanical Engineering , Purdue University, USA
Powder compaction plays a relevant role in many pharmaceutical, food, ceramic and metallurgical manufacturing processes, so much so that microstructure evolution during consolidation has direct impact on the end-product properties and performance. This process involves a variety of coupled physical mechanisms at the particle-scale (e.g., elasto-plastic deformations, formation of solid bridge, friction, and fracture) that govern the properties and performance of the final product (i.e., tablet hardness, swelling, disintegration and dissolution for pharmaceutical powders pressed into solid tablets for oral administration). Therefore, it is of paramount importance to fundamentally understand these coupled mechanisms in order to optimize manufacturing processes and to improve product design.
Predictive multi-scale modeling and simulation of microstructure formation and evolution during compaction of granular solids requires research efforts in three main fronts. First, the development of predictive constitutive models of inter-particle and particle-pore interactions that account for high levels of confinement and a variety of physical mechanisms. Second, the development of concurrent multi-scale strategies that combine a detailed description of the granular scale with the computational efficiency typical of continuum-level models. Third, the experimental characterization of particle’s mechano-chemical properties required in the model. In this Seminar I will present progress in these three fronts, including: (i) nonlocal contact formulations that overcome the typical, but unrealistic, assumption that contacts are independent regardless the confinement of the granular system, (ii) a quasi-static particle mechanics approach which concurrently solves for contact forces at the granular scale, for nonlocal deformations at the mesoscale, and for equilibrium at the macroscale, (iii) a pore-scale model that enables the investigation of swelling, disintegration and dissolution from simulated tablet microstructures, and (iv) characterization techniques that utilize modeling and experimental methodologies in lockstep coordination with each other at the particle scale.
Dr. Marcial Gonzalez
Dr. Marcial Gonzalez is an Assistant Professor in the School of Mechanical Engineering at Purdue University since 2014, and he is a co-Director of the Particle, Powder, and Compact Characterization Laboratory. He was a Research Associate at Rutgers University with an affiliation with the Mechanical and Aerospace Engineering Department and with the NSF Engineering Research Center for Structured Organic Particulate Systems. He received his Ph.D. in Aeronautics, with a minor in Materials Science, from the California Institute of Technology in 2010. He is a Mechanical Engineer from the University of Buenos Aires, Argentina, and received a MS in Aeronautics from Caltech.
His current research focuses on predictive, multi-scale modeling and simulation of microstructure evolution in confined granular systems, with an emphasis in manufacturing processes and the relationship between product fabrication and performance. Application areas of interest include: consolidation and compaction of powders, continuous manufacturing and performance of pharmaceutical solid products, and energetic and explosive materials.