热稳定性混合生长型聚晶金刚石研制

Manufacture of Polycrystalline Diamond with Heat Stability Based on Interfacial Growth

本文在分析国内外钻探用聚晶金刚石应用及性能基础上,研制开发耐高温界面生长型聚晶金刚石,采用0.05钴片或钴铁片(5%铁)扩散工艺,对工艺组装制备及合成工艺条件进行详细分析论证,建立一种界面生长型聚晶金刚石合成工艺,由于采用强酸处理方法去除残余金属钴存在处理不彻底及对性能影响大缺陷,通过分析国内外聚晶热稳定性基础上,得出生长型聚晶晶间结构即Co存在状态是提高热稳定性关键,通过降低进入聚晶金属Co含量和改变晶间物相及组成,即主要是改变金属Co存在状态,加入适量金属Ti、W,在扩散生长同时生成新的固溶体-硬质合金,即TiC-Co、WC-TiC-Co固溶体,从而改变聚晶显微组织中残留Co存在状态,并对样品进行电镜扫描、电子探针分析、转靶X射线衍射分析等分析,研究证明其结构基本是D—D键结合的高晶体,晶粒金刚石之间是D—D键错综连接形成多孔网状结构,产品具有高自锐性和热稳定性,热稳定达到1473K。最后对生长机理进行初步分析,并提出界面生长机理。

This paper discusses thoroughly the assembly and synthesis process of polycrystalline diamond based on the analysis of current application and performance of polycrystalline diamond used in drilling, and introduces a synthesis method of interfacial-growth-based polycrystalline diamond similar to the performance of the counter product of General Electronics. We find that the key of the thermal stability lies in the intercrystalline structure-the state of the element Co through analyzing thermal stability of all kinds of domestic and oversea polycrystalline diamonds. For there are many defects using strong acids to remove the residual Co, we adopt a new way to reduce the quantity contained of Co and change the intercrystalline structure of Co by adding appropriate and take shape engineering plastics solid phase-the Ti and W which produce TiC and WC with diamond solid phase of TiC-Co and WC-Tic-Co at last. The checking results of the products based on electronic probes and X-ray diffraction showed that the basic structure of the product is crystalline and polycrystalline, which is intricate and complicated D-D bond upon the interface of diamond crystalline with a net structure, This product has a high sharpness and thermal stability which reach 1473K. At last, this paper summarizes the synthesis mechanism and presentes the theory of ＂interfacial growth. ＂ polycrystalline diamond based on the interfacial growth.