V.M. Sglavo – CerSciTech - UNITN 2011 • sintering • reaction bonding (Si (s) + NH 3(g) Si 3 N 4(s) + Si (s) ) • dimox (directed metal oxidation) (2 Al (s) + 3/2 O 2(g) Al 2 O 3(s) ) • thermal spray (thick coatings) • from powders • from melt • from vapour/gas (CVD, sputtering) • from solution (sol-gel) • from techno-polyimers Processing technologies for ceramic materials Problems: • high temperatures (Al 2 O 3 : 2050°C; ZrO 2 : 2700°C) • high volumetric shrinkage upon solidification (≈20-25%) • large crystalline grains (limited mechanical resistance) Problems: limited productivity (thin coatings, powders, microcomponents)
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V.M. Sglavo – CerSciTech - UNITN 2011 Processing ... · V.M. Sglavo – CerSciTech - UNITN 2011 processing from powders! T T gas (reacting) sintering! reaction bonding, dimox!
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Problems:!• high temperatures (Al2O3: 2050°C; ZrO2: 2700°C)!• high volumetric shrinkage upon solidification (≈20-25%)!• large crystalline grains (� limited mechanical resistance)!