Effects of AlN and BCN Thin Film Multilayer Design on the Reaction Time of Ni/Ni-20Cr Thin Film Thermocouples on Thermally Sprayed Al2O3
Effects of AlN and BCN Thin Film Multilayer Design on the Reaction Time of Ni/Ni-20Cr Thin Film Thermocouples on Thermally Sprayed Al2O3
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DOI：
10.3390/s19153414
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发表时间：
2019-08-01
期刊：
影响因子：
3.9
通讯作者：
Malatyali, Hatice
中科院分区：
文献类型：
--
作者：
Tillmann, Wolfgang;Kokalj, David;Malatyali, Hatice
薄膜热电偶被广泛用于表面的局部温度测定。然而，根据使用环境的不同，薄膜热电偶需要覆盖耐磨或抗氧化的顶层。针对塑料挤出用宽缝喷嘴，采用直流磁控溅射法结合氮化铝（AlN）和硼碳氮（BCN）薄膜制备了Ni /Ni-20 Cr薄膜热电偶。一方面，改变氮化层的沉积参数以影响AlN和BCN薄膜的化学组成和形貌。另一方面，改变氮化物层的位置（热电偶下方、热电偶上方、热电偶周围）。这两个因素进行了研究有关的塞贝克系数和热电偶的反应行为的影响。分析了氮化物薄膜对Ni和Ni-20 Cr薄膜的形貌、物理结构、晶粒尺寸、电阻和硬度的影响。研究表明，塞贝克系数不受热电偶的不同结构的影响。然而，热电偶的反应时间可以通过在薄膜上添加导热顶涂层来显著改善，而顶涂层应该具有粗糙的结构和低的氮含量。
Thin film thermocouples are widely used for local temperature determinations of surfaces. However, depending on the environment in which they are used, thin film thermocouples need to be covered by a wear or oxidation resistant top layer. With regard to the utilization in wide-slit nozzles for plastic extrusion, Ni /Ni-20Cr thin film thermocouples were manufactured using direct-current (DC) magnetron sputtering combined with Aluminiumnitride (AlN) and Boron-Carbonitride (BCN) thin films. On the one hand, the deposition parameters of the nitride layers were varied to affect the chemical composition and morphology of the AlN and BCN thin films. On the other hand, the position of the nitride layers (below the thermocouple, above the thermocouple, around the thermocouple) was changed. Both factors were investigated concerning the influence on the Seebeck coefficient and the reaction behaviour of the thermocouples. Therefore, the impact of the nitride thin films on the morphology, physical structure, crystallite size, electrical resistance and hardness of the Ni and Ni-20Cr thin films is analysed. The investigations reveal that the Seebeck coefficient is not affected by the different architectures of the thermocouples. Nevertheless, the reaction time of the thermocouples can be significantly improved by adding a thermal conductive top coat over the thin films, whereas the top coat should have a coarse structure and low nitrogen content.