首页|基于平台巴西劈裂试验下WC-Co硬质合金的动态响应与失效特性

基于平台巴西劈裂试验下WC-Co硬质合金的动态响应与失效特性

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为获取WC-Co硬质合金在动态拉伸加载下的力学性能和失效机制,设计了动态平台巴西劈裂试验.结果发现,WC-Co硬质合金具有典型的弹脆性特征,且断裂应变随着加载应变率的增加而略有增加.在一维应力波加载下,WC-Co硬质合金的动态抗拉强度随应变率的增加而增加,表明其应变率效应具有明显的正相关性,该效应的产生机制与典型陶瓷类材料是一致的,即由I型裂纹的亚临界扩展决定.对回收破碎试样进行微观形貌观察,发现平台圆盘中间位置处微观断裂模式主要为沿晶断裂,且在拉应力作用下形成韧窝断裂形貌;在靠近加载点位置区域,受多向应力作用,材料不仅存在韧窝断裂,在单个晶粒的局部劈裂表面还存在河流花样的解理断裂.宏观角度上,WC-Co硬质合金表现出明显的脆性特征,但微观角度却发现有局部塑性变形特征.
Dynamic Response and Failure Characteristics of WC-Co Cemented Carbide Under Platform-Based Brazilian Splitting Test
The dynamic platform-based Brazilian splitting experiments were designed in order to obtain the mechanical property and failure mechanism of WC-Co cemented carbide under dynamic tensile loading.Results show that the WC-Co cemented carbide has the typical elastic-brittle characteristic,and its failure strain increases slightly with the strain rates.The dynamic tensile strength of WC-Co cemented carbide increases with the strain rates under one-dimensional stress wave loading,which indicates that the strain rate sensitivity of the composite has obvious positive correlation.The mechanism is consistent with typical ceramic materials,which is decided by subcritical propagation of type-I cracks.The microstructure characterizing results of recycled specimen show that the fracture mode of middle position of platform-based disc is mainly intergranular fracture,and forms dimple fracture by tensile stress.At the location near loading point,the fracture microstructure not only has the dimple fracture,but also has river-patterned cleavage fracture for individual grains under multi-directional stress effect.From macroscopical view,the WC-Co cemented carbide shows obvious brittle characteristics,but from microscopic view,local plastic deformation characteristics exists.

WC-Co cemented carbideplatform-based Brazil splittingdynamic mechanical propertyfracture mechanism

张健、张清贵、辛红敏

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湖北文理学院 纯电动汽车动力系统设计与测试湖北省重点实验室, 湖北 襄阳 441053

西北工业大学 航空发动机高性能制造工业和信息化部重点实验室, 陕西 西安 710072

湖北超卓航空科技股份有限公司, 湖北 襄阳 441000

WC-Co硬质合金 平台巴西劈裂 动态力学性能 断裂机制

中国博士后科学基金面上项目襄阳市基础研究类科技计划新能源汽车与智慧交通湖北省高等学校优势特色学科群项目

2021M7011302022ABH006271XKTD062023

2024

中国材料进展
中国材料研究学会 西北有色金属研究院

中国材料进展

CSTPCD北大核心
ISSN:1674-3962
年,卷(期):2024.43(3)
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