- 學位論文
具韌性漸層氮化鋁鉻矽鈦釩AlCrSiTiVN硬質鍍膜設計與機械性質分析
Mechanical Properties and Coating Design of AlCrSiTiVN Nanocomposite Thin Films
摘要
本研究使用陰極電弧沉積系統製備漸層之多元AlCrSiTiVN硬質薄膜，選用鈦靶、鋁鉻矽三元合金靶(Al：Cr：Si合金比例6：3：1)與鈦釩合金靶(Ti：V合金比例4：6)沉積漸層之多元AlCrSiTiVN硬質薄膜於碳化鎢與矽晶片上且以高純度反應氣體(氮氣，N2)鍍製TiN薄膜做為介層(Interlayer)，利用介層的設計提高附著力並形成漸進結構，控制不同靶電流改變AlCrSiTiVN薄膜成分與結晶結構。本研究探討控制不同合金靶電流比例(TiV 70A/AlCrSi 70A、TiV 50A/ AlCrSi 95A、TiV 95A/ AlCrSi 50A)所製備的AlCrSiTiVN漸層硬質薄膜元素含量的機械性質差異、結構改變等，並設計找出最佳化參數藉以改善其在高溫高磨耗之精密溫熱鍛成形加工之應用。高溫氧化退火中，利用管型爐將薄膜置於空氣中二小時，分別在500度與700度進行高溫氧化試驗。 本實驗使用場發射掃描電子顯微鏡(FE-SEM)、高解析穿透式電子顯微鏡(HR-TEM)與高解析X射線繞射分析儀(XRD/GIXRD)觀察薄膜高溫處理前後之斷面、表面形貌微結構分析，及化學分析電子光譜儀(ESCA)做高溫氧化之縱深成分分析與鍵結分析，以洛式壓痕試驗機與光學顯微鏡鑑定薄膜附著力，利用動態衝擊試驗機進行常溫與高溫抗疲勞韌性試驗，再以能量光散射儀(EDS)分析衝擊後薄膜破損情形，最後以奈米壓痕量測常溫、高溫之薄膜硬度值。 結果顯示靶電流(70A/70A)所製備的AlCrSiTiVN-1漸層硬質薄膜在常溫時擁有最佳的硬度值32.87 GPa與抗衝擊疲勞特性，可耐衝擊達45萬次；AlCrSiTiVN漸層硬質薄膜高溫氧化後會形成氧化層結構，鋁含量會影響到薄膜熱穩定性，因此得到鋁含量最高的AlCrSiTiVN-0.5(TiV/AlCrSi靶電流比例為50 A/95 A)薄膜有最好的抗氧化性。
並列摘要
AlCrSiTiVN multicomponent thin films were prepared on silicon and tungsten carbide samples using a cathodic arc deposition system. Ti60V40 and Cr60Al30Si10 cathodes were used for the deposition of AlCrSiTiV multicomponent thin films. By controlling the Ti60V40 and Cr60Al30Si10 cathode current ratio, the microstructure and composition of the AlCrSiTiVN coatings were changed. For the high temperature oxidation analyses, annealing of the deposited AlCrSiTiVN coatings at 500°C and 700°C in air were conducted. The microstructure of the AlCrSiTiV multicomponent thin films were characterized by using a field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope(HRTEM), and an X-Ray diffraction(XRD) instrument. The chemical composition and bonding structures of the oxidized coatings were identified by electron spectroscope for chemical analysis, (ESCA). Mechanical properties including adhesion ,hardness and Young's modulus were measured by using a Rockwell indentation testerand a nanoindenter. A dynamic impact fatigue test was used to evaluate the impact fatigue performacne of the deposited AlCrSiTiV thin films. The results showed that the AlCrSiTiVN-1 film with equal caothde currents of Ti60V40 and Cr60Al30Si10 cathodes had the highest hardness of 33 GPa due to the smallest grain size 13.2nm . The hardness increased with decreasing grain size down to a critical value 10–20 nm. The results of room temperature impact test showed that AlCrSiTiVN-1 film possessed the best impact resistant due to its high hardness and fracture toughness. At 500˚C, the impact test results also showed that AlCrSiTiVN-1 film still had good resistance to impact fatigue because vanadium oxide were formed to provide lubricity at high temperature. From the XRD analyses, AlCrSiTiVN films had fcc-NaCl structure, vanadium pentoxide (V2O5 ) were formed after annealing at 500˚C. AlCrSiTiVN-0.5 film with the highest Al contents had the best thermal oxidation resistance. Al2O3、VO2、AlVO4 and V2O5 were formed after annealing at 700˚C. The 700 ˚C impact test results showed that AlCrSiTiVN-0.5 film had the best impact resistantance.