摘要
现代制造业的迅速发展对WC基硬质合金涂层的硬度、断裂韧性、耐磨性等使用性能提出了越来越高的要求。本文设计制备了含有WB化合物的新型WC-WB-Co硬质合金涂层。针对不同WB含量的WC-WB-Co涂层的相组成和断裂韧性进行了研究,利用材料体视学方法定量化分析了裂纹扩展形式及路径,提出了断裂韧性的变化机制。研究结果表明:WC-WB-Co涂层中有三元W-Co-B相生成;设计制备的新型硬质合金涂层具有高的断裂韧性;新型涂层增韧机理是高硬度W-Co-B相的存在有效增大了裂纹扩展阻力,并使涂层中裂纹扩展路径发生变化,提高了裂纹扩展所需能量,从而使涂层的断裂韧性得到增强。
The rapid development of modern manufacturing industries puts forward higher and higher requirements on the service performances of WC based cemented carbide coatings, such as the hardness, fracture toughness and wear resistance. In this paper, a new type of WC - WB - Co coating containing WB compound was designed. The phase composition and fracture toughness of WC - WB - Co coatings with different WB contents were studied. The pattern and path of crack propagation were quantitatively an- alyzed by stereology methods, and the mechanism of fracture toughness was proposed. The results show that the WC - WB - Co coatings consist of W - Co - B phases ; the new cemented carbide coatings have high fracture toughness. The toughening mechanism of the new type of coating is that the W - Co - B pha-ses with high hardness could enhance the resistance of crack propagation effectively and change the crack propagation path, which result in the increase of the required crack extension energy. Hence the fracture toughness of the coating is enhanced.
出处
《中国体视学与图像分析》
2017年第2期166-172,共7页
Chinese Journal of Stereology and Image Analysis
基金
国家自然科学基金重点项目(51631002)
作者简介
谢丽杰（1990-），男（汉），河北。硕士。研究方向：新型硬质合金。
通信作者：宋晓艳，教授，博士生导师。E—mail：xysong@bjut．edu．cn
