论文标题
超高温陶瓷HFC，ZRC，TIC，HFN，ZRN和TIN的反应性激光合成用于增材制造
Reactive Laser Synthesis of Ultra-high-temperature Ceramics HfC, ZrC, TiC, HfN, ZrN, and TiN for Additive Manufacturing
论文作者
论文摘要
超高温度的陶瓷（UHTC）是需要极高温度弹性，对化学侵略性环境，磨损和机械应力的应用的最佳结构材料。由于各种障碍，使用基于激光的添加剂制造（AM）处理UHTC尚未完全实现。在这项工作中，研究了选择性激光反应烧结（SLR）技术，用于生产近网状UHTC陶瓷，例如HFC，ZRC，TIC，TIC，HFN，ZRN和TIN。 IV组过渡金属和金属氧化物前体材料被化学转化，并使用CH4或NH3气体中的单步选择性激光处理将UHTC的层粘结到UHTC层中，这些激光器可能与普遍的粉末床融合技术兼容。首先研究了金属（HF，ZR和Ti）或金属氧化物（HFO2，ZRO2和TIO2）颗粒的转化，以检查与单分量前体系统SLR相关的反应机理和体积变化。单独的碳化物和硝酸盐的SLR处理在化学计量计的UHTC相位附近产生的金属或金属氧化物的加工。但是，对于单个成分前体，气体固体反应性引起的体积变化导致了残留应力和产品层的破裂。为了减轻转化诱导的应力，采用复合金属/金属氧化物前体来补偿金属（转化过程中膨胀）或金属氧化物前体（合同）的体积变化。
Ultra-high-temperature ceramics (UHTCs) are optimal structural materials for applications that require extreme temperature resilience, resistance to chemically aggressive environments, wear, and mechanical stress. Processing UHTCs with laser-based additive manufacturing (AM) has not been fully realized due to a variety of obstacles. In this work, selective laser reaction sintering (SLRS) techniques were investigated for the production of near net-shape UHTC ceramics such as HfC, ZrC, TiC, HfN, ZrN, and TiN. Group IV transition metal and metal oxide precursor materials were chemically converted and reaction-bonded into layers of UHTCs using single-step selective laser processing in CH4 or NH3 gas that might be compatible with prevailing powder bed fusion techniques. Conversion of either metals (Hf, Zr and Ti) or metal oxides (HfO2, ZrO2, and TiO2) particles was first investigated to examine reaction mechanisms and volume changes associated with SLRS of single-component precursor systems. SLRS processing of metal or metal oxide alone produced near stoichiometric UHTC phases with yields up to 100 wt% total for carbides and nitrides. However, for single component precursors, gas-solid reactivity induced volumetric changes resulted in residual stresses and cracking in the product layer. To mitigate conversion-induced stresses, composite metal/metal oxide precursors were employed to compensate for the volume changes of either the metal (which expands during conversion) or the metal oxide precursor (which contracts).
