Enhanced Hardening Effects on Molybdenum-Doped WB 2 and WB 2 –SiC/B 4 C Composites
Enhanced Hardening Effects on Molybdenum-Doped WB 2 and WB 2 –SiC/B 4 C Composites
复制标题
增强钼掺杂 WB 2 和 WB 2 → SiC/B 4 C 复合材料的硬化效果
DOI：
10.1021/acs.chemmater.2c00386
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发表时间：
2022
影响因子：
8.6
通讯作者：
Kaner, Richard B.
中科院分区：
文献类型：
--
作者：
Pangilinan, Lisa E.;Hu, Shanlin;Turner, Christopher L.;Yan, Jinyuan;Kavner, Abby;Mohammadi, Reza;Tolbert, Sarah H.;Kaner, Richard B.
采用电阻电弧熔炼法从纯元素中合成了二硼化钨（WB 2）固溶体，并对其力学性能进行了表征。WB 2型结构保持高达30原子百分比（at%）Mo取代。W0.70Mo0.30B2在0.49 N时的最大维氏硬度为45.7 ± 2.5 GPa，是迄今为止最硬的WB 2固溶体。与此事实相一致，高压径向衍射研究表明，Mo取代WB 2增强了金属-硼键合，因为固溶体支持高差应力，体积模量为355 ± 2 GPa。通过添加0- 30wt%的B_4C或SiC，合成了WB_2和W_（0.70）Mo_（0.30）B_2复合材料，研究了复合材料的非本征硬化效应。这些复合材料的维氏硬度，因为第二相沉淀表现出外在的影响。虽然WB 2 -30重量%的B4 C表现出最高的硬度（在0.49 N下为53.8 ± 6.0 GPa），但WB 2 -30重量%的SiC表现出最慢的氧化速率。这项工作提供了新的见解定制过渡金属硼化物系统优化硬度，晶粒形态和热稳定性。
Tungsten diboride (WB2) solid solutions with increasing molybdenum (Mo) substitution were synthesized by resistive arc-melting from the pure elements and characterized for their mechanical properties. The WB2-type structure is maintained up to 30 atomic percent (at%) Mo substitution. W0.70Mo0.30B2achieved a maximum Vickers hardness of 45.7 ± 2.5 GPa at 0.49 N, resulting in the hardest WB2solid solution to date. In agreement with this fact, high-pressure radial diffraction studies indicate that substitution of Mo into WB2strengthens metal–boron bonding, as the solid solution supports high differential stress and has a bulk modulus of 355 ± 2 GPa. WB2and W0.70Mo0.30B2composites were then synthesized with increasing additive content (0–30 wt%) of B4C or SiC to study extrinsic hardening effects through multiphase formation. These composites show extrinsic effects on the Vickers hardness because of secondary-phase precipitation. While WB2–30 wt% B4C exhibited the highest hardness (53.8 ± 6.0 GPa at 0.49 N), WB2–30 wt% SiC demonstrated the slowest oxidation rate. This work offers new insights for tailoring transition-metal boride systems with optimized hardness, grain morphology, and thermal stability.