摘要
通过控制烧结气氛制备了均质和梯度结构的硬质合金基体,并用化学气相沉积制成涂层硬质合金及切削刀片。采用光学显微镜和扫描电镜观察,通过显微硬度抗弯测试和切削试验对均质基体和梯度基体的涂层硬质合金的组织特征与性能进行对比研究。研究结果表明,梯度结构的硬质合金基体可以提高涂层硬质合金的抗弯强度;相对于均质基体的涂层硬质合金刀片,梯度基体的涂层硬质合金刀片在保持耐磨性能的同时能显著提高抗冲击性能。基体涂层合金的组织结构及断口特征显示,梯度基体表层韧性区可阻碍裂纹的扩展。
The coated cemented carbides with gradient and normal structure substrates were processed by gas-composition-adjusting sintering and chemical vapor deposition respectively. The microstructure and mechanical performance of coated cemented carbides with gradient and normal structure substrates were studied by optical microscopy, scanning electron microscope, microhardness measurement, transverse rupture and cutting test. The coated cemented carbide with the gradient structure substrate has higher transverse rupture strength, longer impact cutting life and the same wear resistance, compared to the coated cemented carbide with the normal structure substrate. Microstructure and fracture surface show that the tough surface zone in the gradient substrate can prevent crack propagation.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2005年第5期776-779,共4页
Journal of Central South University:Science and Technology
基金
国家自然基金委优秀重点实验室专项基金资助项目(50323008)
关键词
梯度功能材料
硬质合金
裂纹扩展
涂层
functionally graded structure
cemented carbide
crack propagation
coating
