摘要
对以B4C为供硼剂、以Y2O3为催渗剂的WC-20Co硬质合金渗硼表面进行了从室温到1300℃连续升温渗硼过程的XRD动态物相分析,在此基础上探讨了钇-硼共渗机理。结果表明,在真空烧结升温期间,B4C分解出来的活性硼原子除了在压坯表面上形成硼化物外,还形成了硼原子富集。这些硼原子向压坯内扩散,形成弥散分布的羽毛状W2Co21B6化合物。同单独渗硼相比,钇在钇-硼共渗过程中有拓宽渗硼温度范围、促进B4C脱碳分解和硼原子向压坯内扩散等催化渗硼作用,从而改善了渗硼层的组织结构,明显提高了渗硼层的韧性。
The dynamic XRD phase analysis for the coated surface with B4C. and Y2O3 of WC-20Co cemented carbides samples during vacuum-heating from room temperature to 1 300degreesC was carried out by high-temperature X - ray diffraction apparatus. The yttrium-boronization mechanism was explored on the basis of the above results. The results shown that, the high concentration active boron atoms were released from the boron-supply agent B4C, located on the blank surface and diffused into the Co-phase in the blank, leading to forming the dispersed feathered W2Co21B6 compound besides forming boron-bearing compounds on the blank surface. By contrast with alone boronization, the element yttrium in the boronization agent broadens the boronization temperature range during vacuum-sintering, promotes the de-carbonisation decomposition of B4C and diffusion of active boron atoms into WC-Co blank etc, which improve the morphology and the toughness of the boronization layer.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2003年第4期305-308,共4页
Rare Metal Materials and Engineering
基金
天津市自然科学基金资助项目(993602811)
