摘要
对Ti(C ,N)基金属陶瓷进行了表面氮化处理。用SEM ,EPMA ,TEM/EDX分析了材料表面显微组织的特征。研究发现 ,材料表面形成了富N、富Ti的相 ,它们包覆在硬质颗粒的表面。硬质颗粒周围的环形相的体积分数大大减少。晶粒尺寸也明显减小。紧邻表面硬化层 ,出现了一层金属粘接相含量较高的过渡层。表面氮化处理使Ti(C ,N)基金属陶瓷的表面硬度得到明显的提高 ,而基本上不影响其抗弯强度。表面较高的N的活度是促使各合金元素扩散 。
Ti(C,N)-based cermet whose chemical composition is C-N-Ti-W-Co-Ni was subjected to a heat-treatment in nitrogen. The surface microstructure was characterized with SEM, EPMA and TEM/EDX. It is found that in the surface zone of the heat-treated cermet, the carbonitride grains become smaller obviously, and a great part of rim is dissolved in the solid binder during the heat-treatment. A new layer of nitrogen-rich and titanium-rich carbonitride is formed on the Ti(C,N) cores. A gradient zone rich in binder is also induced just below the harden surface. In addition, the surface hardness of the cermet is improved by the treatment in nitrogen, while the TRS (transverse rapture strength) is hardly changed. Higher nitrogen activity in the surface zone is the driving force to make these alloy elements diffused, resulting in the surface microstructure.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2003年第3期262-267,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金 ( 5 0 0 740 17)
国家自然科学基金( 5 0 10 40 0 6)
湖北省自然科学基金 ( 2 0 0 0J0 32 )资助项目
