“Extrusion-based sintering-assisted additive manufacturing (ES-AM) has enabled the fabrication of intricate metal structures, spanning from simple geometries to complex lattice structures. The sintering process plays a vital role in metal densification that requires effective design and optimization of sintering processes for high-quality sintered parts. Notably, sintering behaviors in ES-AM differ from those in traditional methods, primarily due to the heterogeneous distribution of particles and pores induced by the anisotropic fabrication nature of AM. This literature review offers an overview of process and mechanisms of sintering that lay the foundation for the development of ES-AM. Theories governing solid-state sintering and liquid-phase sintering are summarized to advance a thorough comprehension of associated sintering mechanisms. Computational studies on sintering processes at different length scales are also discussed, including atomic-level molecular dynamics, micro-level simulations (Monte Carlo, phase field, and discrete element method), and macroscopic continuum models. The distinctive anisotropic sintering behaviors in the ES-AM process are further elucidated across multiple levels. Ultimately, future directions for ES-AM, encompassing materials, sintering process, and sintering mechanisms, are outlined to guide research endeavors in this field. This review summarizes multi-scale sintering behaviors in both traditional manufacturing and AM, contributing to a deeper understanding of sintering mechanisms and paving the way for innovations in the next generation of manufacturing, particularly in AM involving sintering mechanism.”
Full paper published to ASME Digital Collection on 26 February 2025 https://asmedigitalcollection.asme.org/manufacturingscience/article-abstract/doi/10.1115/1.4068066/1213004/Sintering-Mechanisms-in-Metal-Extrusion-based?redirectedFrom=fulltext