In-service Catastrophic Failure: or Controlling the Grain Boundary Network Evolution

运行中的灾难性故障：或控制晶界网络的演化

• 批准号: 2888456
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2888456
• 关键词: service; Catastrophic; Failure; Controlling; Grain

Hardmetal tools are a key for our production industries relying on cutting, milling, drilling, and turning. Cemented carbides (WC-Co) are one of the most prominent powder metallurgy processed materials use for cutting tool applications. This is due to a combination of excellent hardness/wear resistance and toughness with low cost compared to alternatives such as polycrystalline diamond. During service (e.g. in machining) , however, the composite structure is subjected to a combination of high mechanical and thermal loads, where hard carbide particles are joint by soft cobalt binder, deforms until excessive wear and fracture reduce the performance and lifetime. Crack paths in WC-Co predominantly follow WC/WC and WC/Co grain and phase boundaries at low cobalt concentrations1. While the WC grain boundary character, the grain boundary network, is characterised for differently doped cemented carbides2-5, knowledge of how the grain boundary network evolves during service and ultimately allows for crack formation along grain boundaries is absent.

硬质合金刀具是我们依赖切削、铣削、钻孔和车削的生产行业的关键。硬质合金 (WC-Co) 是用于切削工具应用的最重要的粉末冶金加工材料之一。这是因为与多晶金刚石等替代品相比，它兼具优异的硬度/耐磨性和韧性，而且成本低廉。然而，在使用过程中（例如在机械加工中），复合材料结构会承受高机械和热载荷的组合，其中硬质碳化物颗粒通过软钴粘合剂接合，变形直至过度磨损和断裂，从而降低性能和寿命。在低钴浓度下，WC-Co 中的裂纹路径主要遵循 WC/WC 和 WC/Co 晶界和相界 1。虽然 WC 晶界特征（即晶界网络）针对不同掺杂的硬质合金 2-5 进行了表征，但对于晶界网络在使用过程中如何演变并最终导致沿晶界形成裂纹的知识却缺乏了解。