软压头技术在金刚石室温疲劳实验中的应用研究

金刚石作为世界上最硬的材料,长期以来,人们普遍认为其在室温下没有疲劳破坏。为了验证金刚石是否存在着疲劳破坏,本文提出了一种软压头技术(在压缩实验时,所用压头材料的硬度相比被测材料的硬度低得多),详细阐述了其原理和优点。利用CBN、Si3N4、Tib2和Silver Steel材料制做的压头进行了金刚石室温疲劳破坏实验,得到了金刚石室温疲劳曲线,找出了金刚石疲劳破坏临界应力值,实验结果充分说明了金刚石在室温下确实存在着疲劳破坏现象,并验证了软压头技术的可靠性。

Applications and Studies of Soft Impressor Technique in the Fatigue Experiment of Diamond at Room Temperature

In a long time,people thought that at room temperature there was no fatigue crack in diamond--the hardest material in the world. In order to verify this parlance,the soft impressor technique is put forward in this paper, which means the hardness of the impressor is much lower than that of the material to be pressed and tested. Its principles and advantages are introduced. The fatigue crack experiment of diamond at room temperature is conducted with the impressors made of CBN,Si3N4 ,Tib2 and silver steel . Fatigue curve of diamond at room temperature is gained, and the critical stress to cause fatigue crack in diamond is found from the experiment. All this approves adequately that there is fatigue crack phenomena in diamond at room temperature and the soft impressor technique is reliable.