o 1 Al203 have two advantages first, chemically stable al oxidized second, higher melting point(2020C) A1(660C refractory y use in industrial furnace construction Why shouldnt AlO3 be chosen for certain applications where metallic 、 aluminum has been used
Why shouldn’t Al2O3 be chosen for certain applications where metallic aluminum has been used ? 1、Al2O3 have two advantages: first , chemically stable ; Al oxidized second , higher melting point (20200C) Al (6600C) refractory use in industrial furnace construction
Questions 1. What materials are available to you in this book 2. What fundamental characteristics metals have? 3. Please shade metallic elements in periodic table and give some examples of alloys 4. Please list two principal advantages of Al2O3 relative to metallic al 5. What's the most limiting property of ceramIcs
Questions 1. What materials are available to you in this book? 2. What fundamental characteristics metals have? 3. Please shade metallic elements in periodic table and give some examples of alloys. 4. Please list two principal advantages of Al2O3 relative to metallic Al. 5. What’s the most limiting property of ceramics
The most limiting property of ceramics brittleness Recent development in ceramic technology are expanding the utility of ceramics for structural application not by eliminating their inherent brittleness, but by increasing their strength to sufficiently high levels(greater than 700MPa and increasing their resistance to fracture
The most limiting property of ceramics brittleness Recent development in ceramic technology are expanding the utility of ceramics for structural application not by eliminating their inherent brittleness, but by increasing their strength to sufficiently high levels (greater than 700MPa) and increasing their resistance to fracture
2、Al2O3 MgO sio2SiN4 Oxide Nonoxide ceramIcs ceramIcs At least one metallic element tone of five nonmetal element( C, n,o, p and S Carbide [5kB: baid Nitride [5naitraid Oxide [5Cksaid Phosphide [5fCsfaid] Sulphide. [5sQlfaid
2、Al2O3 MgO SiO2 Si3N4 At least one metallic element +one of five nonmetal element (C, N, O, P and S) Carbide [5kB:baid] Nitride [5naitraid] Oxide [5Cksaid] Phosphide [5fCsfaid] Sulphide. [5sQlfaid] Oxide ceramics Nonoxide ceramics
3 One metallic element plus one of five nonmetallic elements(C.N.o. P or S) 1|1A IIIA IVA VA VIA VII AHe 4 6 B C NOF N 11 12 VII 1415 Mg III B IV B VB VI B VII B IB IBAISi P S CI 202122232 25 26 27 29 31 3435 K Ca Sc Ti Mn Co N Cu G A Br K 8 39 40 41 42 44 45 464748495051 Rb Sr Nb Mo T Ru Rh Pd In Te Xe 555657727374757677787980818283848586 Ir 60 61 63646566 68 Pr Nd Pm SmE Gd Tb DY H o E Tm Yb 9091 92 10010110 Th P N P Am C Bk Cf E Fm Md FIGURE 1. 1-4 Periodic table with ceramic compounds indicated by a combination of one or more metallic elements(in light color) with one or more nonmetallic ele ments(in dark color). Note that elements silicon(Si) and germanium(Ge) are in cluded with the metals in this figure, but were not in Figure 1. 1-2. This is because, in elemental form, Si and Ge behave as semiconductors(Figure 1. 1-15). Elemental tin(Sn) can be either a metal or a semiconductor, depending on its crystalline struc
3、One metallic element plus one of five nonmetallic elements (C, N, O, P, or S)