1 Chapter I INTRODUCTION

2  Materials lie at the base of all technological advances.  Advanced materials and advanced processing of materials are critical to the nation’s quality of life, security, and economic strength. I-1. Materials  Materials are matters that you use to make something useful, e.g., tableware( 食 ), clothings( 衣 ), vehicles( 行 ), buliding( 住 ), machines, instruments, tools, and components( 科技生產 ).  Advanced materials are the building blocks of advanced technologies.

3 The major classes of materials are:  Metals ( 金屬材料 )  Ceramics ( 陶瓷材料 )  Polymers ( 高分子材料 )  Composites ( 複合材料 )  Semiconductors ( 半導體材料 )  Biomaterials ( 生物材料 ) I-2. Classification of Materials

4 Dense ( heavy) ● High hardness (much higher than polymers, but mostly lower than ceramics) High mechanical strength Ductile and high toughness Can be deformed into complex shapes Electrically conductive High thermal conductivity Medium melting point (much higher than polymers, but mostly lower than ceramics) I-3. Metals I-3. Metals

5  Advances in processing: Fabricated from metal powders by compacting them into a desired shape at high temperature and pressure in a process known as powder metallurgy (PM). Reduced productionn costs through PM will continue to impact the aerospace and automotive fields.

6 I-4. Ceramics (typically, compounds of metallic and nonmetallic elements) Medium dense (lighter than metals but heavier than polymers) Mostly extremely hard High mechanical strength (extremely stiff ) Brittle and low toughness High melting point and high temperature stability(refractory)

7 Highly electrically insulative (but with significant exceptions, e.g., ceramic ionic conductors, superconductors,…) Low thermal conductivity ( with significant exceptions, e.g., AlN, BN, diamond, graphene, carbon nano tube,…) Resistance to chemical attack Resistance to absorption of foreign substances

8  Current and potential applications ˙Automotive industry ： engine components. ˙High-performance integrated circuit substrate and package materials, e.g., AlN. ˙Superconductors, YBa2Cu3O7 and Ba2Sr2CaCu2Ox.  Next-generation computers:Flat Panel Display (FPD)/ ceramic electro-optic components ( 螢光材 料 )

9 I-5. Polymers  Relatively easy to synthesize  Low density (light)  Low mechanical strength  Tend to soften at moderate temperatures (limiting the use at low temperatures).  Easily formed into complex shapes ( low temperature processability)  High electrical resistivity( with exceptions)  Extremely low thermal conductivity  Chemical inertness.

10 I-6. Composites comprising two or more different types of materials and possessing the desired properties of the components . Carbon fiber-epoxy composite-the strength and rigidity.  Metal matrix (with ceramic as filler) composite-airframe material  Ceramic-matrix (with other ceramic as filler) composites.  matrix: continuous phase ; filler : noncontinuous

11  High thermal conductivity AlN or BN / Polymer Composite           AlN or BN particles (filler) high thermal high thermal conductivity conductivity high electrical high electrical resistivity resistivity low thermal low thermal expansion expansion polymer (matrix) rigidity rigidity mechanical mechanical strength strength ahesive ahesive high breaking- high breaking- through voltage through voltage low temperature processing low temperature processing

12 I-7. Semiconductors materials possessing semiconducting properties. (usually a ceramic or a polymer.)  Silicon, germanium, GaAs, CdTe and Inp.  Semiconductors must be processed in ways that permit precise controlof composition and structure.  Current and potential applications. Information transfer, changing from electrical to optical signals. The size scale of microelectronic devices.

13 I-8. Biomaterials I-8. Biomaterials materials that can be implanted into human bodies.(can be metals, ceramics or polymers)  to be implanted into human body.e.g., artificial teeth, bones, skins and etc.  must be compatible with body tissues.

14 I-9. Typical Examples of Advanced Materials Development (A) Flat Panel Display (FPD) (phosphors) (carbon nano tube)

15 (B) White Light LED Lighting Chip holders or chip submounts (high thermal comsuctivity ceramics ； AlN)

16 (C) Multilayer Ceramic Capacitor

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18 Nano-sized dielectric ceramic powder

19 (D) Electronic Substrates (with high thermal conductivity ： AlN )

20 4. Cathode: 1.Absorption 2. Electron injection 3. Regeneration Dye-Sensitized Solar Cells mechanism ： Properties and photoelectric conversion efficiencies of the DSSC’s fabricated using the TiO 2 electrode synthesized in our Lab. or using the commercial TiO 2 powders. Our research goals ： to synthesize various nanopowder and nanostructured materials (TiO 2, ZnO,CeO 2 …) with different morphologies for the fabrication of semiconductor electrode for DSSCs. (E) Photocatalysts

21 A.Objective Chemical Energy conversion Electrical Energy Requirements: High efficiency (= amount of electrical energy obtained per unit amount of chemical energy input). Low environmental pollution (environmental friendly or green) Low cost (F) Solid-Oxide Fuel Cell (SOFC)

22 (a) Traditional Approach fuel (coal, oil, or natural gas) + air High Temp Combustion gas CO 2, H 2 O,…+ pollutants Gas turbine generator Steam turbine generator electrical energy Fuel (chemical energy) Heat (thermal energy) mechanical energy electrical energy Heat 1 (thermal energy) mechanical energy electrical energy Fuel (chemical energy) steam Heat 2 (thermal energy)

23 (b) Fuel Cell Approach Fuel (H 2 or CO) Anode (porous) Electrolyte (dense) Cathode (porous) O -2 O2O2 load Oxidizer (air or O 2 ) Over all reaction H 2 + 1/2O 2 H 2 O (g) + electrical energy One-step conversion (the highest conversion ever obtained)

24 Cathode (Air Electrode) 1/2O 2 (g)+2e - = O -2 2 (s) Requirements ： (a)High electronic conductivity. (b)Chemical and dimensional stability. (c)A suitable thermal expansion coefficient. (d)Compatibility and minimum reactivity. (e)Sufficient porosity (oxygen from the gas phase to the air electrode/electrolyte interface). ◎ Materials (formulation) ： Lanthanum manganite ( 鑭錳氧化物 ) doped with alkaline and rare-earth elements porous tube.

25 It dissociates at 1000°C at low oxygen pressures( atm). The electronic conductivity: hopping of an electron hole between the +3 and +4 valence states of Mn. Conductivity is enhanced by doping with a divalent ion such as calcium (Ca) or strontium (Sr).  Materials Synthesis ： high-purity: La 2 O 3 and MnO 2 solid state reaction Lanthanum  Component fabricationElectrolyte  Materials (formulation) YSZ (8% Y 2 O 3 -ZrO 2 ) has been the most successfully employed. Yttrium oxide stabilizes the high-temperature cubic phase and generates oxygen vacancies; an oxygen vacancy is created for every mole of the dopant Y 2 O 3 : oxygen-ion conductivity. manganite (e.g.,La 0.9 Sr 0.1 MnO 3 )

26  Materials Reguirement, Synthesis and Fabrication free of porosity uniformly thin high oxygen-ion conductivity transport number for electrons as close to zero as possible. ~40-μm-thick layer electrochemical vapor depositon (EVD). 2MeCl y + yH 2 O = 2MeO y/2 + 2yHCl and Anode (Fuel Electrode) O -2 (s) + H 2(g) 1000 ℃ H2O (g) + 2e  Reguirement electronically conducting and sufficient porosity.  Materials (formulation) Nickel (cobalt or ruthenium) in YSZ, thermal expansion sinter forming a skeleton of YSZ around the nickel particles. Nickel powder slurry; EVD process; deposition of a Ni-YSZ slurry sintering.

27 Cross-flow planar design for a solid-oxide fuel cell.

28 P-type perovskite oxide reversible oxidation-reduction behavior. Oxygen excess or deficiency, depending upon the ambient oxygen partial pressure and temperature. Co-flow monolithic design for a solid-solid-oxide fuel cell.

29 Tubular design for a solid-solid-oxide fuel cell.

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32 G. Furnace Repairing (steel company) 渣線 ( 鎂碳磚 ) 壁部 ( 鋁鎂質灌注材 ) ( 鋁鎂不燒磚 ) 底部 ( 沖擊預注塊 ) ( 鋁鎂質灌注材 ) 煉鋼一廠容量 160 噸 煉鋼二廠容量 260 噸 部位材質 Al 2 O 3 SiO 2 MgO 渣線鎂碳磚 -- >75 C:13 壁部 鋁鎂不燒磚 鋁鎂灌注材 >90<1>5 底部 鋁鎂 灌注材 >90<1>5 沖擊區 鋁尖晶石 預注塊 >88<1>4 流鋼嘴 座磚 鋁尖晶石 預注 >88<1>4 攪拌管 座磚 鋁尖晶石 預注 >88<1>4 永久層 腊石磚 高鋁磚 >18 >75 <78 <25 - 斷熱層 高強度 斷熱板 鎂橄欖石 雲母 盛 鋼 桶盛 鋼 桶 煉 鋼 製 程 主 要 爐 體 用 耐 火 材 料煉 鋼 製 程 主 要 爐 體 用 耐 火 材 料 ( 要求：抗爐渣 / 鋼液侵蝕性、耐鋼液沖蝕與抗熱震特性 ) ( 所處條件：高溫，鹽基度變化大的爐渣接觸反應，並經鋼液、 爐渣的劇烈沖擊，以及 LF 電弧輻射熱和激烈的熱震作用。 ) [ 壁部 ( 使用鋁鎂澆注料 ) ･一廠～ 165 回 ( 原用高鋁磚為 70 回 ) ･二廠～ 190 回 ( 原高鋁磚為 100 回 )] ( 一廠 ~ 80 回；二廠 ~ 100 回 )

33 煉 鋼 製 程 主 要 爐 體 用 耐 火 材 料煉 鋼 製 程 主 要 爐 體 用 耐 火 材 料 全部為 MgO-C 磚 轉 爐轉 爐 部位材質 CSiCMgO 爐口鎂碳磚 Upper Cone 鎂碳磚 出鋼口鎂碳磚 壁磚鎂碳磚 加料側鎂碳磚 底吹鎂碳磚 底部磚鎂碳磚 永久層燒成鎂磚 MgO > 90% ( 要求：抗爐渣 / 鋼液侵蝕性、耐鋼液沖蝕、抗熱震與抗氧化特性 ) (~ ℃、 爐渣侵蝕、構造性剝 落、熱震剝落、機械磨耗、氧化脫碳 ) 使用回數 ~ 回 (with slag splashing)

34 Al 2 O 3 -SiC-C 鋁矽碳磚 煉 鐵 製 程 主 要 爐 體 用 耐 火 材 料煉 鐵 製 程 主 要 爐 體 用 耐 火 材 料 魚雷車 衝擊區 鐵水區 渣線區 天井區 ( 要求 ： 抗爐渣 / 鐵水侵蝕性、 耐鐵水沖蝕、 抗熱震與抗氧 化特性 ) 三脫作業、爐渣侵蝕、 鐵水之攪動沖刷、氧 化及熱震剝落 裝銑實績 ~30 萬噸