在保護性薄膜的發展中，硬質薄膜之氧化特性逐漸受到關注，其重要性在提高工件於高溫應用下之性能和可靠度。本研究重點為探討添加不同硼含量對於 (AlCrNbTiBx)N多元氮化物薄膜之機械性質和氧化特性的影響。結果顯示，硼的添加會導致顯著的微觀結構變化，薄膜截面從明顯的柱狀結構，過渡到更緻密的形貌。此外，硼含量的增加可以減小晶粒尺寸，進而提高硬度，在加入硼含量為5.8 at% 可達到最大值27.0 GPa。然而，進一步增加硼含量反而會使硬度降低，其歸因於形成過多較軟之非晶相BN及過小之晶粒，抑制了強化特性。
除了機械性能的提升，微觀結構的緻密化也對薄膜氧化行為產生影響。添加硼含量2.3 at% 的薄膜中尤為顯著，其氧化物厚度減小，並且在表面形成了緻密的 (Al,Cr)2O3保護層，有效阻止了氧的滲入。然而，硼含量更高的薄膜因為形成較不具保護性的B2O3，破壞了氧化層的完整性，導致在高溫下發生較劇烈的氧化行為。
本研究藉由調變(AlCrNbTiBx)N薄膜中的硼含量，針對其機械性能和抗氧化特性進行優化，透過策略性地調控薄膜中的硼含量，可望提高含硼薄膜於保護性塗層之應用潛力。

The importance of oxidation characteristics has been receiving growing attention in the development of hard coatings, with the objective of enhancing the performance and reliability of workpieces at elevated temperatures. This study focuses on the effect of boron content in improving the mechanical and oxidation characteristics of (AlCrNbTiBx)N multi-component nitride coatings. The incorporation of boron induces microstructural alterations, transitioning from a distinct columnar feature to a denser structure. Additionally, increasing boron content reduces crystallite size of coatings, while enhancing hardness, reaching a peak value of 27.0 GPa with the introduction of 5.8 at% B. However, a further increase in boron content leads to a diminishing effect on hardness, attributed to the excessive formation of soft amorphous BN phase and the reduction of grain size to a critical limit.
In addition to the mechanical enhancement, the microstructural densification exerts a profound influence on oxidation resistance. This phenomenon is most pronounced in coatings with 2.3 at% B, where oxide thickness is reduced, and a compact surface with Al-rich protective oxide scale effectively impedes the ingress of oxygen. Nevertheless, it becomes evident that higher boron content disrupts the integrity of the oxide scale due to the formation of less protective B2O3, resulting in a deterioration of oxidation resistance at elevated temperatures.
In summary, this study underscores the pivotal role of boron content in tailoring the mechanical properties and oxidation resistance of (AlCrNbTiBx)N coatings. It highlights the potential for optimizing boron-containing coatings by strategically adjusting boron content, offering promising implications for protective coating applications.

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