ABSTRACT Obtaining both high hardness and toughness is a challenge in B4C-nano-adhesive composites. Solving the inhomogeneous distribution of nano-adhesives in B4C and forming the chemical bonding at grain boundary is an effective method. Here, we reported that the uniform distribution of titanium diboride (TiB2)-reinforced B4C composites synthesized by high-pressure and high temperature (HPHT). It is found that HPHT sintering can effectively inhibit the grain growth and increase the relative density. Moreover, HPHT sintering can cross high reaction energy barrier and effectively promote the formation of chemical bonding at grain boundary between B4C and TiB2. The optimal hardness and toughness value reach 30.0 ± 0.9 GPa and 7.87 MPa·m1/2, respectively. The improvement of hardness and toughness in the final products are ascribed to the strengthening of nanoTiB2 connection of B4C boundary and intergranular fracture mechanism. This work suggests a new way to achieve the uniform distribution of nanoTiB2 in B4C and form the chemical bonding at grain boundary, which is of great significance to the further development of TiB2-reinforced B4C composites with excellent mechanical properties.

中文翻译：

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高压高温反应烧结制备TiB2增强B4C复合材料

摘要 获得高硬度和高韧性是 B4C 纳米粘合剂复合材料中的一个挑战。解决纳米粘合剂在B4C中分布不均匀，在晶界形成化学键是一种有效的方法。在这里，我们报道了通过高压高温 (HPHT) 合成的二硼化钛 (TiB2) 增强的 B4C 复合材料的均匀分布。发现高温高压烧结能有效抑制晶粒长大并提高相对密度。此外，高温高压烧结可以跨越高反应能垒，有效促进 B4C 和 TiB2 晶界处化学键的形成。最佳硬度和韧性值分别达到30.0±0.9 GPa和7.87 MPa·m1/2。最终产品硬度和韧性的提高归因于B4C边界和晶间断裂机制的纳米TiB2连接的加强。该工作提出了一种实现纳米TiB2在B4C中均匀分布并在晶界形成化学键的新方法，这对进一步开发具有优异力学性能的TiB2增强B4C复合材料具有重要意义。