Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9718
標題: 氮化鉻薄膜微結構與氧化行為之研究
A Study of the Microstructure and Oxidation Behavior of CrN Thin Films
作者: 王慶鈞
Ching, Wang Chun
關鍵字: CrN;氮化鉻;microstructure;Oxidation Behavior;Residual Stress;微結構;氧化行為;殘留應力
出版社: 材料工程學研究所
摘要: 
中文摘要
本研究乃是針對以非平衡磁控濺射技術沈積於AISI304不銹鋼的氮化鉻鍍膜之微結構、殘留應力、抗高溫氧化性及氧化前後鍍膜微硬度變化做探討。以X光繞射儀、掃瞄式電子顯微鏡、穿透式電子顯微鏡進行微結構與成分分析,並以微氏硬度計量測鍍膜氧化前後的硬度。
對未氧化的氮化鉻鍍膜進行殘留應力量測,其殘留應力大小約為4.25 GPa。由SEM結果發現,氧化溫度在500℃之前的試片,其表面型態相似,鍍膜表面的粗糙度隨氧化溫度升高而加大。從XRD與TEM繞射圖分析結果得知氮化二鉻相轉換現象發生於溫度500℃,之後隨著氧化溫度越高,氧化及相轉換情況越明顯,所以氮化鉻鍍膜在高溫氧化過程除了產生Cr2O3氧化物,其內部亦會有CrN與β-Cr2N間的相變化。
鍍膜經過300℃氧化的硬度值與剛鍍著的試片接近,氧化溫度在500℃、600℃、700℃時的硬度值升高,可由文獻中氮化二鉻的硬度大於氮化鉻來解釋,而800℃硬度值驟降的原因,可由鍍膜結構變得較為鬆散,晶粒變得更粗大,且氧化膜崩裂,無法承受壓痕器所施加之荷重來解釋。

CrN coatings were deposited by unbalanced magnetron sputtering (UBM) on AISI 304 stainless steel. The oxidation behavior of the CrN-coated steel at elevated temperatures was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the hardness of the films was measured by Vickers hardness indentor. In addition, the residual stress of the CrN-coated steel was determined by deflection method.
The residual stress in the as-deposited CrN films was measured to be about 4.25 GPa. From SEM results, it can be found that the surface of the specimens oxidized in air below 500℃ for 60 min remains similar to the as-deposited specimens, and the surface roughness of the CrN coatings increases with oxidation temperatures at above 600℃. XRD and TEM results indicate the phase transformation from CrN to Cr2N occurs at 500℃, and the extent of β-Cr2N and Cr2O3 and the grain size of the phases increase with the oxidation temperature. Not only the Cr2O3 oxides but also the phase transformation of CrN are observed during the oxidation process of the coatings.
The hardness of the specimen oxidized at 300℃ is almost the same as the as-deposited specimens, and the hardness of the CrN-coated steel increases with the oxidation temperatures up to 700℃. This can be explained by the fact that the hardness of Cr2N is higher than that of CrN.The sharp decrease in the hardness of the specimens oxidized at 800℃ is partly due to the grain growth of the CrN and Cr2N coating layer at high temperature.
URI: http://hdl.handle.net/11455/9718
Appears in Collections:材料科學與工程學系

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