- 學位論文
熱均壓製程對ZnO系列陶瓷之特性影響研究
The Influences of Hot Isostatic Pressing on the Characteristics of ZnO-based Ceramics
摘要
透明導電氧化物（Transparent Conducting Oxide, TCO）材料主要為氧化銦錫(Tin-doped Indium Oxide, ITO)，因其具有優異的導電性(10-3~10-4 Ωcm)及可見光穿透率(~80 %以上)。但由於銦的成本高且具毒性，故學界業界皆積極發展替代材料，一般氧化物中又以ZnO基材最具潛力。在學術上已有不少文獻表明ZnO摻雜氧化鋁及氧化鎵等之替代材料所鍍製之薄膜擁有良好的導電性與透光性，但大部分研究重點著重在濺鍍參數的調控，甚少研究濺鍍靶材與薄膜之間的關聯性，亦有少數文獻指出靶材性質對鍍膜性質是有影響的。因此本研究利用熱均壓燒結(Hot Isostatic Pressing, HIP)製備ZnO系列陶瓷，進而探討其燒結密度、顯微結構、結晶結構、電學性質，並藉由硬度及抗彎強度瞭解此類陶瓷材料之機械性質。 實驗結果顯示ZnO經熱均壓燒結後密度可略幅上升，AZO及GZO經HIP燒結後更可接近全緻密，且因密度之增加使電阻率下降至10-3~10-4 Ωcm。結晶結構方面，AZO與GZO皆會產生二次相。三種陶瓷在預燒結1300℃後熱均壓將使硬度值提升，試片最佳值為ZnO HIP-1250℃為215 Hv，AZO HIP-1000℃為322 Hv，GZO-3 HIP-1000℃為530 Hv。而抗彎強度則受密度影響，密度越高其抗彎強度越高，ZnO最高值為104 MPa，AZO為215 MPa，GZO-3為266 MPa，且經預燒結1300℃後HIP-1000℃及HIP-1250℃，其中抗彎最佳值之ZnO HIP-1250℃為182MPa，AZO HIP-1250 ℃為260 MPa。 關鍵詞：氧化鋅、氧化鋅鋁、氧化鋅鎵、電阻率、熱均壓、微硬度、抗彎強度。
並列摘要
lTin-doped indium oxide (ITO) is the predominant material transparent conducting oxide (TCO）film due to its excellent resistivity (10-3~10-4 Ωcm) and visible transmittance (＞80 %). However, the substitute for ITO indium is extensively studied because indium is not only expensive but also toxic. Zinc oxide (ZnO) is also a potential material for TCO film. Numerous studies had indicated that aluminum-doped zinc oxide (AZO) and galium-doped zinc oxide (GZO) films exhibit outstanding conductivity and transmittance. However, most researches focused on the modifications of sputtering parameters. The correlation between sputtering target and film was rarely investigated though the sputtering target plays an important role on the film performances. This study examined the effects of hot isostatic pressing (HIP) on the sintered density, microstructure, crystal structure and electrical properties of ZnO-based ceramics. The mechanical properties, including hardness and bending strength, were also investigated in this study. The results showed that the sintered density of ZnO is slightly increased by HIP. However, after HIP, the sintered densities of AZO and GZO are much improved to ~100% dense. Furthermore, the resistivites of AZO and GZO can be decreased to 10-3~10-4 Ωcm. In the crystal structure, secondary phases were generated in the AZO and GZO ceramics. HIP can increase the hardness of ZnO-based ceramics. The hardnesses of ZnO, AZO, and GZO can be increased to 215, 322, and 530 Hv, respectively. Besides, the bending strength is improved with increasing the sintered density of the ceramic. The highest bending strengths of ZnO, AZO, and GZO are 104, 215, and 266 MPa, respectively. After HIP, the bending strengths of ZnO and AZO can be further improved to 182 and 260 MPa, respectively. Keyword: ZnO, AZO, GZO, Resistivity, Hot isostatic pressing, Microhardness, Flexural strength.