Binder Jetting of hardmetals: a literature review and patent landscape analysis on commercial and in-house developed granules and liquid binders

In recent years , Binder Jetting (BJT) has attracted significant interest within the Hardmetals industry. BJT relies on a layer-by-layer powder deposition, followed by the selective jetting of a binder. Literature on BJT of Hardmetals shows considerable effort towards optimising printing parameters. However, one cannot dissociate the ability to fabricate accurate and dense parts from the properties of the granules and binders, which are often overlooked. Specifically, for Hardmetals, the limited variety of available grades and the challenges to densify the granules are two urgent issues. Regarding the binders, the challenges are extended across the whole BJT ecosystem. Binders are still largely seen as simple sacrificial glues to bond powders. However, the chemistry behind them and how they can influence or promote the formation of deleterious phases cannot be disregarded, particularly for Hardmetals. In this context, this review provides an overview of BJT for Hardmetals, from academia to industry. It particularly addresses strategies for densifying Hardmetal granules and for efficient bonding provided by the liquid binders, specifically developed for Hardmetals. From research studies and communications to a dedicated patent analysis, this review analyses the different and most relevant approaches towards the development of Hardmetal granules and binders for BJT.