Thermal stability of nanocomposite Mo2BC hard coatings deposited by magnetron sputtering
Thermal stability of nanocomposite Mo2BC hard coatings deposited by magnetron sputtering
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DOI：
10.1016/j.surfcoat.2018.06.006
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发表时间：
2018-09
影响因子：
5.4
通讯作者：
S. Gleich;B. Breitbach;N. Peter;R. Soler;H. Bolvardi;J. Schneider;G. Dehm;C. Scheu
中科院分区：
文献类型：
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作者：
S. Gleich;B. Breitbach;N. Peter;R. Soler;H. Bolvardi;J. Schneider;G. Dehm;C. Scheu
研究硬质涂层在热载荷作用下的热稳定性及其微观结构和力学性能的可能变化是至关重要的。此外，先进的加热研究还可以为退火过程中发生的晶粒生长机制提供反馈，从而有助于预测生产高性能硬涂层的最佳生长后退火条件。在这里，我们研究了在工业室内双极脉冲直流磁控溅射沉积在硅衬底上，衬底温度为380 °C的Mo2BC的热响应。在高温下进行ex -situ - in-situ x射线衍射和透射电镜研究，以跟踪结构的变化。沉积的纳米复合涂层在非晶基体中呈现出小的球形纳米晶体（直径1.2 nm），而在较高的退火温度下，得到了一个完整的晶体结构，主要由长度达1 μm的细长互连晶体组成。与沉积态相比，硬度和杨氏模量分别提高了8%和47%。硅衬底的分层只发生在840 °C以上的温度下。因此，我们对热处理过程中微观和纳米结构演变的详细研究表明，840 °C以下的热处理是改善纳米复合Mo2BC涂层结晶度和力学性能的合适方法。
The investigation of hard coatings under thermal load is crucial in order to obtain information on the thermal stability and possible changes of microstructure and mechanical properties. In addition, advanced heating studies may also provide feedback for the grain growth mechanism occurring during annealing and thus, help to predict optimum post-growth annealing conditions for producing high-performance hard coatings. Here, we investigate the thermal response of Mo2BC, deposited by bipolar pulsed direct current magnetron sputtering in an industrial chamber on a silicon substrate at a substrate temperature of 380 °C.Ex-situandin-situX-ray diffraction and transmission electron microscopy studies are performed at elevated temperatures to track changes in the structure. Whereas the as-deposited nanocomposite coating exhibits small spherical nanocrystals (1.2 nm in diameter) embedded in an amorphous matrix, a fully crystalline structure, mainly consisting of elongated and interconnected crystals with lengths of up to 1 μm, is obtained at elevated annealing temperatures. Hardness and Young's modulus increase by ~8% and ~47%, respectively, compared to the as-deposited coating. Delamination from the silicon substrate only occurs at temperatures above 840 °C. Thus, our detailed study of the micro- and nanostructure evolution upon thermal annealing suggests that heat treatments below 840 °C are a suitable method to improve the crystallinity and mechanical properties of nanocomposite Mo2BC coatings.