Advanced ceramics are required in many applications including armor, engine components, and wear parts for abrasive, corrosive, and high temperature environments. Heterogeneous structuring in these materials has the potential to unlock extrinsic mechanisms that improve damage tolerance, of vital importance for structural functionality. However, traditional ceramic powder processing and forming techniques limit the design space to simple geometries with chemically homogenous microstructures. Thus, additive manufacturing by direct ink writing (DIW) was applied to fabricate multi-phase carbide specimens with tailored composition and mesostructure. A custom DIW system was developed to allow simultaneous extrusion and mixing of multiple inks, comprised of ceramic particulate suspensions, through a single nozzle. Boron carbide (B₄C) and silicon carbide (SiC) were chosen for this study due to their excellent mechanical properties. Aqueous B₄C and SiC inks were loaded to 47.5 vol.% ceramic content and showed yield-pseudoplastic behavior. The carbide inks were characterized and modified to exhibit similar rheological behavior (yield stress and viscosity), and were used to produce B₄C-SiC parts with either discrete or continuous composition variation. Specimens were hot pressed at 35 MPa and 1950°C, yielding near full density with hardness (Knoop) values of 20-23 GPa. Tailored heterogeneity, achieved via active in-line mixing, is revealed through microstructural characterization. Cracking observed in the specimen with discretely varied composition is the result of thermally-induced residual stress, and is elucidated through analytical calculations.

在许多应用中都需要使用高级陶瓷，包括装甲，发动机部件以及易磨损，腐蚀性和高温环境下的易损件。这些材料中的异质结构可能会解锁改善损伤耐受性的外在机制，这对于结构功能至关重要。然而，传统的陶瓷粉末加工和成型技术将设计空间限制为具有化学均一的微观结构的简单几何形状。因此，通过直接墨水书写（DIW）进行的增材制造被应用于制造具有定制组成和介观结构的多相碳化物样品。开发了定制的DIW系统，以允许通过单个喷嘴同时挤出和混合由陶瓷颗粒悬浮液组成的多种油墨。碳化硼（B本研究选择了₄ C）和碳化硅（SiC），因为它们具有出色的机械性能。B ₄ C和SiC水性油墨的陶瓷含量为47.5 vol。％，并表现出屈服假塑性行为。对硬质合金油墨进行表征和改性，使其表现出相似的流变行为（屈服应力和粘度），并用于生产B ₄具有离散或连续成分变化的C-SiC零件。将样品在35 MPa和1950°C的温度下热压，以硬度（努氏）值为20-23 GPa产生接近全密度的样品。通过主动在线混合实现的定制异质性通过微观结构表征得以揭示。在样品中观察到的具有离散变化的组成的裂纹是热引起的残余应力的结果，并且通过分析计算得以阐明。