Ti(C,N)基金属陶瓷功能梯度材料的制备

利用热等静压技术高温高压的特点,在金属陶瓷的基体上获得了硬质梯度涂层.借助扫描电镜、X射线衍射仪、显微硬度计和电子探针分析技术对N化后材料的组织、结构、性能进行了测试分析.结果表明,高温高压N化能在表面形成硬质梯度薄膜,表面区域N的活度梯度是促使各合金元素迁移形成氮化表面层特征组织的最终驱动力.表面硬度和心部韧性提高,并且硬度由表及里逐渐减小,这是由于高温高压氮化处理使材料中的孔洞闭合,微裂纹和缺陷的减少使得材料的性能得到显著提高.

Processing of functionally graded Ti(C, N)-based cermets

The high temperature high pressure hot isostatic pressing technology was used for deposition of hard coating on Ti(C,N)-based cermet.The microstructure and properties of the sample were investigated by optical microscope,scanning electron microscope,X-ray diffraction,transmission electron microscope,electron probe microanalysis and microhardness tester.The results show that a surface zone rich in titanium and nitrogen was induced by the heat-treatment.The high nitrogen activity in the surface region was the driving force for outward transport of titanium and inward transport of tungsten in the cobalt binder.Toughness and hardness were improved and at the same time hardness gradient was formed.This is the high temperature high pressure N_2 which make the holes closed and the defect vanished,and this is why the tool life prolonged.