Influence of microstructure on hardness and thermal conductivity of hardmetals
Influence of microstructure on hardness and thermal conductivity of hardmetals
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DOI：
10.1016/j.ijrmhm.2019.105170
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发表时间：
2020-04-01
影响因子：
3.6
通讯作者：
Michaelis, A.
中科院分区：
文献类型：
--
作者：
Vornberger, A.;Poetschke, J.;Michaelis, A.
硬质合金或硬质合金由于其优异的机械性能而被广泛应用。通过改变WC晶粒尺寸和钴含量的组合，可以获得具有相同室温硬度的WC-Co硬质合金。然而，这种硬质合金等级的导热率是不相等的。切割等应用可能需要硬度和导热率的某种组合，这意味着需要进行有针对性的调整。在这项研究中，我们对各种硬质合金牌号在20摄氏度至1000摄氏度温度范围内的显微组织、硬度和导热性进行了研究。结果表明，Co含量、WC晶粒尺寸和Cr 3C 2含量对复合材料的热导率有较大影响。此外，在室温下具有相同硬度的硬质合金等级在高温下保持的硬度非常不同。对于高温应用的硬质合金牌号的选择，这些发现有助于在Co含量和WC粒度方面选择正确的成分。
Hardmetals or cemented carbides are used in a wide range of applications due to their excellent mechanical properties. WC-Co hardmetals with the same room temperature hardness can be obtained by different combinations of the WC grain size and cobalt content. However, the thermal conductivity of such hardmetal grades is not equal. Applications such as cutting may require a certain combination of hardness and thermal conductivity, which means that a targeted adjustment is desirable. In this study a wide range of hardmetal grades was studied in respect of microstructure, hardness and thermal conductivity in the temperature range between 20 degrees C and 1000 degrees C. Results show that thermal conductivity is considerably influenced by Co content, WC grain size and Cr3C2 content. Furthermore, hardmetal grades with the same hardness at room temperature retain hardness very differently at elevated temperatures. For the selection of hardmetal grades for high temperature applications these findings help to choose the right composition in regard to Co content and WC grain size.