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Binder Jetting (BJT), a powder-based additive manufacturing technology, has been shown to be a fast and reproducible green shaping process for many different metals. Due to its high productivity and versatility in material processing, BJT is gaining increasing importance in the manufacturing sector. It can also be used for the production of WC-Co hardmetals, a primary ceramic-based composite often used for tools and wear parts. Five different BJT printers from four different manufacturers were evaluated to assess their effectiveness and feasibility in producing hardmetals based on the same WC-12 wt.% Co starting powders. The analysis focused on comparing the properties of the resulting hardmetals, as well as evaluating the printing performance. The results show that all tested BJT printers are fundamentally well suited for producing green hardmetal parts, which can achieve full density after sintering. This work highlights the potential of BJT technology in hardmetal manufacturing for tool production. [ABSTRACT FROM AUTHOR]

Cathode formulation, which describes the amount of cathode active material (CAM), conductive additives (CAs), and binder within a cathode compound, is decisive for the performance metrics of lithium-ion battery (LIB) cells. The direct measurement of electronic resistance can be an enabler for more time- and cost-efficient cathode formulation improvements. Within this work, we correlate the electronic resistance with the electrochemical performance of cathodes. Two different high Nickel NCM cathode materials and numerous CAs are used to validate the findings. A detailed look into the resistance reduction potential of carbon black (CB) and single-walled carbon nanotubes (SWCNT) and their mixtures is made. Finally, an impact estimation of cathode formulation changes on LIB key performance factors, such as energy density and cost, is shown. [ABSTRACT FROM AUTHOR]

Hardmetals are cemented carbides consisting of the hard ceramic phase WC and the ductile metallic binder Co. They offer an outstanding combination of hardness and fracture toughness. Hence, they have a widespread use across the manufacturing industry. However, due to the increasing requirements for tool material, the combination of the beneficial properties of hardmetal and diamond is a long sought-after objective. In this work, a new approach was evaluated to reduce the formation of graphite due to the phase transformation of diamond during the sintering of compounds together with hardmetal. Earlier trials could not fully suppress the phase transformation despite using alternative Ni-instead of conventional Co-based binder systems and field-assisted sintering (FAST) to reduce required sintering temperatures and time. To lower the amount of graphite formed during sintering even further, a reactive sintering process was developed. The increased sinter activity due to the in situ synthesis of WC has the potential to decrease the needed temperature to achieve a pore-free compact. For the first time, a WC-Ni hardmetal produced from elemental powders was successfully used as a matrix in a diamond-enhanced cemented carbide (DECC). Different approaches regarding carbon sources and the extent of reactive material were pursued. The introduction of a carbon deficit by adding metallic W to a mixture of WC and Ni, which is essentially partial reactive sintering, leads to an increased relative density compared to the reference of 97.3%. [ABSTRACT FROM AUTHOR]

For several years, researchers have been exploring the use of the binder jetting powder-based additive manufacturing process to produce WC-Co hardmetals. Compared to other additive manufacturing processes, binder jetting has the potential for high-volume production. However, due to the powder-based approach, the resulting green bodies typically have low green density, limiting the achievable hardness and requiring higher Co content. Choosing the appropriate starting powder and post-processing can extend previous limitations and allow the selection of a suitable powder based on the application. This investigation focuses on exploring and evaluating the correlation between varying morphologies of WC-Co starting powders, their processability using the BJT method, and the resultant mechanical properties of sintered components. [ABSTRACT FROM AUTHOR]

Solid-state batteries (SSBs) with Li-ion conductive electrolytes made from polymers, thiophosphates (sulfides) or oxides instead of liquid electrolytes have different challenges in material development and manufacturing. For oxide-based SSBs, the co-sintering of a composite cathode is one of the main challenges. High process temperatures cause undesired decomposition reactions of the active material and the solid electrolyte. The formed phases inhibit the high energy and power density of ceramic SSBs. Therefore, the selection of suitable material combinations as well as the reduction of the sintering temperatures are crucial milestones in the development of ceramic SSBs. In this work, the co-sintering behavior of Li1.3Al0.3Ti1.7(PO4)3 (LATP) as a solid electrolyte with Li-ion conductivity of ≥0.38 mS/cm and LiFePO4 with a C-coating (LFP) as a Li-ion storage material (active material) is investigated. The shrinkage behavior, crystallographic analysis and microstructural changes during co-sintering at temperatures between 650 and 850 °C are characterized in a simplified model system by mixing, pressing and sintering the LATP and LFP and compared with tape-casted composite cathodes (d = 55 µm). The tape-casted and sintered composite cathodes were infiltrated by liquid electrolyte as well as polyethylene oxide (PEO) electrolyte and electrochemically characterized as half cells against a Li metal anode. The results indicate the formation of reaction layers between LATP and LFP during co-sintering. At Ts > 750 °C, the rhombohedral LATP phase is transformed into an orthorhombic Li1.3+xAl0.3−yFex+yTi1.7−x(PO4)3 (LAFTP) phase. During co-sintering, Fe3+ diffuses into the LATP phase and partially occupies the Al3+ and Ti4+ sites of the NASICON structure. The formation of this LAFTP leads to significant changes in the electrochemical properties of the infiltrated composite tapes. Nevertheless, a high specific capacity of 134 mAh g−1 is measured by infiltrating the sintered composite tapes with liquid electrolytes. Additionally, infiltration with a PEO electrolyte leads to a capacity of 125 mAh g−1. Therefore, the material combination of LATP and LFP is a promising approach to realize sintered ceramic SSBs. [ABSTRACT FROM AUTHOR]