Multi-scale Sintering Model of Visco-Elastic Powders

This thesis aims to investigate the sintering process of visco-elastic particles through a multi-scale framework and multi-physics approach. The research examines the sintering process at various scales, ranging from particle-particle interactions at the microscopic scale to continuum deformations at the macroscopic scale. By combining computer simulations and laboratory tests, the investigations gain valuable insights into the micro-macro responses of the sintering process.

The thesis is organized into four distinct yet interconnected chapters that span the entire spectrum of the sintering process. These chapters focus on the following aspects:

• In Chapter 2, we characterise contact rheology. The focus is on understanding the mechanical interactions between particles during the sintering process.

• In Chapter 3, we explore the multi-physics of sintering. It delves into the physical phenomena that occur during sintering considering heat transfer and material flow.

• In Chapter 4, we analyse the influence of material and process parameters on sintering. The study investigates how different material properties and process conditions affect the overall sintering process and its outcomes.

• In Chapter 5, we couple the discrete model to the continuum model for a multi-scale framework. It bridges the gap between the micro- and macro-scales by developing a comprehensive multi-scale model that incorporates both particle-level interactions and macroscopic deformations.

The findings of this research offer an understanding of the sintering process in Additive Manufacturing by integrating microscopic and macroscopic perspectives. Furthermore, this study highlights the potential to continue developing and optimizing the sintering processes using advanced multi-scale modelling techniques via virtual prototyping