Binder Jetting Metal Additive Manufacturing (BJ-MAM), known also as metal 3D-printing, is a powder bed-based additive manufacturing technology. It consists of the deposition of liquid binder droplets to selectively join powder particles to enable the creation of near-net shaped parts, which subsequently are consolidated via sintering process. This technology is known for its capability to process a wide range of different materials and for its orientation towards large volume production series. Binder Jetting has recently been drawing the attention of both the research sphere as well as several industrial sectors. The present review study encompasses the various and most remarkable aspects of BJ-MAM part fabrication. The review covers the material selection and characterisation considerations, followed by the manufacturing process features and the parameter effect on different part properties. It concludes with an overview concerning the most recent case studies with regards to diverse metal alloy developments.

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Bismuth titanate‐based ceramics, pure and doped with 5 mol% WO3, were prepared by reaction‐sintering using a microwave oven. High densities, ≥96% of theoretical density were achieved with very short thermal treatments, with soaking time ranging from 5 to 15 min. Relatively small platelet‐like grains were formed, and microstructure seemed not to be strongly affected by doping nor soaking time. Electrical measurements were performed and, as expected, a decrease of electrical conductivity was observed in WO3‐doped materials. The results of reaction‐sintered samples, both conventional as well as microwave sintered, are compared with those of samples prepared with previously calcined powders and sintered using microwaves as well as a conventional electric furnace.

This work opens a new pathway to fabricate high dimensional stability Invar36 aerospace devices with Binder Jetting technology, for applications where temperature fluctuations directly interfere in the correct performance of high sensibility systems. Since full density part fabrication is one of the main ongoing challenges for Binder Jetting, the leading objective of this work is to study and optimise the main process parameters to increase the final density of Invar36 printed parts. Microstructural analysis and obtained density and CTE values, confirmed the feasibility to fabricate Invar36 parts.

Metadata of the article that will be visualized in OnlineFirst ArticleTitleA study of parameter and post-processing effects on surface quality improvement of Binder Jet 3D-printed Invar36 alloy parts