摘要
在4~6GPa/1000~1400℃/5~30min条件下,用微米金刚石(MD)和碳纳米葱(OLC)混合物作为原材料制备了纳米聚晶金刚石(nPCD)复合材料。采用XRD、FESEM、HRTEM、Archimedes原理和Vickers硬度计表征了nPCD复合材料的组成、形貌、微观结构、密度和硬度。研究了MD和烧结参数对nPCD复合材料的组成、微观结构、性能。结果表明,MD在nPCD复合材料中分布均匀。MD作为晶核促进OLC向金刚石的转换。烧结压力的增加提高了nPCD复合材料的密度和硬度。当烧结压力从4GPa提高到6GPa时,nPCD复合材料的密度从2.72g/cm^(3)增加到3.02g/cm^(3),硬度从41.85GPa增加到56GPa。提高烧结温度和延长保持时间使nPCD复合材料的密度和硬度先升高后降低。在nPCD复合材料中nPCD区域具有孪晶结构。孪晶结构的存在提高了nPCD复合材料的硬度。
Additive-free nano-polycrystalline diamond(nPCD)composite was sintered by using a mixture of microdiamond(MD)and onion-like carbon(OLC)as raw materials at 4~6 GPa/1000~1400℃/5~30 minutes holding time.The composition,morphology,microstructure,density and hardness of the nPCD composite were measured by XRD,FESEM,HRTEM,Archimedes principle and Vickers hardness tester.The effect of MD and high-pressure sintering parameters on the OLC transformation process and the com-position,microstructure,properties of nPCD composite were studied.The results showed that the MD was uniformly distributed in the nPCD composite.MD acted as nu-cleus to promote the conversion of OLC to diamond.The increase of sintering pressure enhanced the density and hardness of the nPCD composite.When the sintering pressure was raised from 4 GPa to 6 GPa,the density of nPCD composite was increased from 2.72 g/cm^(3) to 3.02 g/cm^(3),and the hardness was increased from 41.85 GPa to 56 GPa.The in-crease of sintering temperature and holding time made the density and hardness of the nPCD composite increase first and then decrease.Nanotwinned diamond with 10 nm size appeared in the nPCD region in the nPCD composite.The presence of nanotwinned dia-mond increased the hardness of nPCD composite.
作者
李艳国
代利峰
王志伟
邹芹
LI Yanguo;DAI Lifeng;WANG Zhiwei;ZOU Qin(School of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,China;State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China)
出处
《超硬材料工程》
CAS
2024年第5期1-11,共11页
Superhard Material Engineering
基金
河北省高校重点科研项目ZD2021099。
