Investigation of nitrogen mass transfer within an industrial plasma nitriding system I: The role of surface deposits
Investigation of nitrogen mass transfer within an industrial plasma nitriding system I: The role of surface deposits
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工业等离子渗氮系统内氮传质的研究 I：表面沉积物的作用
DOI：
10.1016/j.surfcoat.2009.08.029
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发表时间：
2010
影响因子：
5.4
通讯作者：
S. Dowey
中科院分区：
文献类型：
--
作者：
P. Hubbard;J. Partridge;E. Doyle;D. McCulloch;M. B. Taylor;S. Dowey
已经提出，在等离子体氮化中，来自腔室内的偏置部件的材料的溅射有助于氮质量传递过程。在这里，我们研究了这种溅射沉积工艺对安装在520°C下运行的大型等离子体氮化系统中的偏压和偏压AISI P20钢样品的氮化响应的影响。氮化实验后，在与AISI P20钢基材相邻的Si基材上观察到Volmer-Weber膜生长产生的具有纳米结构形态的膜。俄歇深度分析表明，在Si衬底上的膜具有4：1的Fe：N的化学计量比。这表明颗粒主要由Fe 4 N组成，并且可以得出结论，它们是由原子和小团簇形成的，所述原子和小团簇是从腔室中的偏置组件溅射的。尽管这些薄膜的沉积，没有显着的改善，在钢样品中观察到的表面硬度，除非偏压施加到他们。此外，在氮化过程后，在偏置的P20样品中实现的最大硬度发生在位于支撑最薄沉积膜的Si样品附近的样品中。这些研究结果不支持的主张，在等离子渗氮，氮传质发生主要是由溅射沉积的氮化铁。
It has been proposed that in plasma nitriding, sputtering of material from biased components within the chamber assists in the nitrogen mass transfer process. Here, we investigate the effects of this sputter deposition process on the nitriding response of biased and unbiased AISI P20 steel samples mounted in a large-scale plasma nitriding system operated at 520°C. Films with nanostructured morphologies resulting from Volmer–Weber film growth were observed on Si substrates placed adjacent to AISI P20 steel substrates after nitriding experiments. Auger depth profiling revealed that the films on the Si substrates had a stoichiometric ratio of 4:1 Fe:N. This suggested that the particles consisted largely of Fe4N and it was concluded that they were formed from atoms and small clusters sputtered from biased components in the chamber. Despite the deposition of these films, no significant improvement in surface hardness was observed in the steel samples unless bias was applied to them. Furthermore, the maximum hardness achieved in biased P20 samples after the nitriding process occurred in the samples positioned adjacent to the Si samples supporting the thinnest deposited films. These findings do not support the proposition that in plasma nitriding, nitrogen mass transfer occurs predominantly by sputter deposition of iron nitride.