- 學位論文
奈米多層AlCrSiN/TiVN薄膜之微結構與機械性質研究
Microstructure Characterization and Mechanical Properties of Multilayered AlCrSiN/TiVN Hard Coatings
摘要
硬質薄膜被廣泛應用於工業界，像是氮化鈦(TiN)、氮化鉻(CrN)等等，其是因為具有較好之機械性質，例如高硬度、抗腐蝕及抗磨耗等等。本研究利用陰極電弧沉積法沉積氮化鋁鉻矽/氮化鈦釩(AlCrSiN/TiVN)多層薄膜於高速鋼、P型(100)矽晶圓及碳化鎢上。在薄膜設計上利用三種不同靶材分別為純鈦靶、鈦釩合金靶及鋁鉻矽合金靶材，在製程中，三顆靶材靶電流控制在70A，以氮化鈦(TiN)作為介層以提高基材與薄膜間附著力，並透過三種不同轉架轉速(1、2、4rpm)控制薄膜週期厚度(Λ)鍍製氮化鋁鉻矽/氮化鈦釩(AlCrSiN/TiVN)奈米多層薄膜。 針對薄膜性質分析部分，採用本校微奈米實驗室之場發射電子顯微鏡(FE-SEM)、X光繞射分析儀(XRD/GIXRD)與高解析穿透式電子顯微鏡(HR-TEM)進行薄膜結構分析，薄膜機械性質利用奈米壓痕量測薄膜硬度與彈性模數，同時利用衝擊疲勞試驗機進行常溫與高溫衝擊性能實驗，透過場發射掃描電子顯微鏡與能量散射光譜分析儀(EDS)觀察薄膜衝擊後之磨損情形，與進行Pin-on-disc 磨耗試驗，探討多層薄膜結構對摩擦系數影響，搭配場發射掃描電子顯微鏡與能量散射光譜分析儀(EDS)了解磨耗試驗後薄膜受損情形，並利用3D表面輪廓儀觀察磨擦軌跡以計算磨耗率以了解抗磨耗性能。 結果顯示，AlCrSiN/TiVN奈米多層薄膜隨著轉架轉速增加，週期厚度有下降趨勢，經由XRD結果顯示，AlCrSiN/TiVN多層薄膜皆屬於fcc面心立方晶B1-NaCl結晶構造，觀察到硬度、彈性模數及抗塑性變形隨著週期厚度降低而增加，其又以AlCrSiN/TiVN-2，週期厚度13.5nm，同時具有高硬度，優良之抗衝擊疲勞性能與較優之抗磨耗性能，由於多層膜結構設計能夠有效抑制晶粒成長導致晶粒細化，降低差排行為所產生之塑性變形，此效果能夠提升薄膜硬度與抗塑性變形能力。
並列摘要
Transition metal nitrides, such as TiN and CrN, have been used as protective hard coatings due to their excellent tribological properties. In this study, multilayered AlCrSiN/TiVN coatings were synthesized by cathodic-arc evaporation. The coatings were deposited onto high-speed steels, tungsten carbides and silicon wafers for evaluation. Ti, TiV and CrAlSi alloy cathodes were used for the deposition of AlCrSiN/TiVN coatings. During the coating process of multilayered AlCrSiN/TiVN, TiN was deposited as an interlayer to enhance adhesion strength between the coatings and substrates. The cathode current of both TiV and AlCrSi cathodes were controlled at 70A respectively. By controlling the different rotation speeds of 1~4 rpm, the deposited multilayered AlCrSiN/TiVN coatings possessed different periodic thicknesses of AlCrSiN and TiVN layers. The multilayered thickness and alloy content of the deposited coatings were correlated with the evaporation rate of cathode materials. The microstructure of the deposited coatings was investigated by a field emission gun high resolutiontransmission electron microscope, equipped with an energy-dispersive x-ray analysis spectrometer (EDS). Glancing angle X-ray diffraction was used to characterize the microstructure and phase identification of the films. Mechanical properties, such as the hardness and elastic modulus, were measured by means of nanoindention. Ball-on-disc wear tests were performed to obtain friction coefficient for understanding the effect of the coatings with different rotation rates on wear behavior. To evaluate the correlation between impact fracture resistance and hardness/elastic modulus ratio of the deposited coatings, an impact test was performed using a cyclic loading device with a tungsten carbide indenter as an impact probe. The experimental result showed that the periodic thickness of AlCrSiN/TiVN coatings decreased with increasing rotation speed. From the analyses of XRD, the AlCrSiN/TiVN coatings exhibited an fcc structure with strong (111) diffraction and other (200), (220) diffraction peaks. It was observed that the AlCrSiN/TiVN-2 multilayered coatings with the period of 13.5nm exhibited the highest hardness and resistance to plastic deformation due to grain refinement and the coherent interface between AlCrSiN and TiVN layers.