通过在晶界处引入碳化硼中间层增强纳米多晶金刚石的强度。

Enhanced strength of nano-polycrystalline diamond by introducing boron carbide interlayers at the grain boundaries.

作者信息

Zhao Bo, Zhang Shengya, Duan Shuai, Song Jingyan, Li Xiangjun, Yang Bingchao, Chen Xin, Wang Chao, Yi Wencai, Wang Zhixiu, Liu Xiaobing

机构信息

Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University Qufu Shandong Province 273165 China

Administrative Office of Laboratory and Equipment, Qufu Normal University Qufu Shandong Province 273165 China.

出版信息

Nanoscale Adv. 2019 Dec 9;2(2):691-698. doi: 10.1039/c9na00699k. eCollection 2020 Feb 18.

DOI:10.1039/c9na00699k

PMID:36133237

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9418207/

Abstract

Polycrystalline diamond with high mechanical properties and excellent thermal stability plays an important role in industry and materials science. However, the increased inherent brittle strength with the increase of hardness has severely limited its further widespread application. In this work, we produced well-sintered nano-polycrystalline (np) diamond by directly sintering fine diamond powders with the boron carbide (BC) additive at high pressure and high temperatures. The highest hardness value of up to ∼90 GPa was observed in the np-diamond (consisting of fine grains with a size of 16 nm) by adding 5 wt% BC at 18 GPa and 2237 K. Moreover, our results reveal that the produced samples have shown noticeably enhanced strength and toughness (18.37 MPa m) with the assistance of the soft phase at the grain boundaries, higher than that of the hardest known nano-twined diamond by ∼24% and a little greater than that of the toughest CVD diamond (18 MPa m). This study offers a novel functional approach in improving and controlling the hardness and stiffness of polycrystalline diamond.

摘要

具有高机械性能和出色热稳定性的多晶金刚石在工业和材料科学中发挥着重要作用。然而，随着硬度增加，其固有的脆性强度增大，这严重限制了它的进一步广泛应用。在这项工作中，我们通过在高温高压下直接将细金刚石粉末与碳化硼（BC）添加剂烧结，制备出了烧结良好的纳米多晶（np）金刚石。在18 GPa和2237 K的条件下添加5 wt%的BC，在np金刚石（由尺寸为16 nm的细晶粒组成）中观察到高达约90 GPa的最高硬度值。此外，我们的结果表明，在晶界软相的辅助下，所制备的样品显示出显著提高的强度和韧性（18.37 MPa m），比已知最硬的纳米孪晶金刚石高约24%，略大于最坚韧的化学气相沉积（CVD）金刚石（18 MPa m）。本研究为改善和控制多晶金刚石的硬度和刚度提供了一种新颖的功能方法。