Toughening of chemically-vapor deposited diamond by means of active incorporation of carbon allotropes

通过主动掺入碳同素异形体来增韧化学气相沉积金刚石

基本信息

批准号：
11650075
负责人：
KAMIYA Shoji
金额：
$ 2.37万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650075/
关键词：
CVD diamond Non-Diamond Carbon Thin Films Adhesive Strength Substrate Bias Crystalline structure Toughening

项目摘要

This research project aimed at toughening of chemically-vapor deposited (CVD) diamond by means of actively incorporating carbon allotropes besides diamond. We studied the following two points and have succeeded to develop CVD diamond with adhesive toughness more than twice as much as that of usual one.Elucidation and control for the toughening mechanism by means of the incorporation of non-diamond carbon allotropes The relations between deposition condition and crystalline structure, and between crystalline structure and strength were examined for the case of CVD diamond deposited under various conditions. As a result, it is for the first time clarified that non-diamond carbon concentrates on the grain boundaries which results in weaker strength of grain boundaries than that of grains, and that selective fracture of grain boundary dissipates the energy which leads to a higher adhesive toughness for the case of the adequate grain size. On the contrary, it was confirmed that toughness of CVD diamond films monotonically decreases with respect to the increase of non-diamond carbon with finer grain size.Realization of thin films with higher toughness by means of structure control Application of bias voltage to the substrates, which is an effective method to control the state of crystalline nuclei on the interface of CVD diamond and substrates, was studied. Together with the knowledge on the effect of deposition condition mentioned above, we examined the possibility to optimize the condition to obtain higher toughness. As a consequence, we succeeded to obtain a CVD diamond coating on tungsten carbide cutting tools with the adhesive toughness of 30 J/m^2 which is more than two times of the conventional one being currently used in industry.

该研究项目旨在通过积极掺入除金刚石之外的碳同素异形体来增韧化学气相沉积 (CVD) 金刚石。我们研究了以下两点，并成功开发了CVD金刚石，其附着韧性是普通金刚石的两倍以上。通过掺入非金刚石碳同素异形体来阐明和控制增韧机理。沉积条件之间的关系对于在不同条件下沉积的 CVD 金刚石的情况，检查了晶体结构和晶体结构以及晶体结构和强度之间的关系。首次阐明非金刚石碳集中在晶界，导致晶界强度弱于晶粒，晶界选择性断裂耗散能量，从而获得更高的粘结力。韧性为晶粒尺寸足够的情况下。相反，已证实CVD金刚石膜的韧性随着晶粒尺寸更细的非金刚石碳的增加而单调降低。通过结构控制实现具有更高韧性的薄膜。研究了控制CVD金刚石与基体界面晶核状态的有效方法。结合上述沉积条件影响的知识，我们研究了优化条件以获得更高韧性的可能性。结果，我们成功地在碳化钨刀具上获得了CVD金刚石涂层，其粘合韧性达到30 J/m^2，是目前工业上使用的传统涂层的两倍多。