Hierarchy of Iron Alloys
Numbering System
Low Carbon Steel
Medium Carbon Steel and its Alloys
With a small amount of Si, Fe 3 C → -Fe and graphite Cast Iron
Clockwise from upper left: gray cast iron, nodular (ductile) cast iron, white iron and malleable iron
Stainless Steels
Tool Steels
Aluminum Alloys
Copper Alloys
Titanium Alloys
Magnesium Alloys
5 Properties: --T melt for glass is moderate, but large for other ceramics. --Small toughness, ductility; large moduli & creep resist. Applications: --High T, wear resistant, novel uses from charge neutrality. Fabrication --some glasses can be easily formed --other ceramics can not be formed or cast. TAXONOMY OF CERAMICS
Need a material to use in high temperature furnaces. Consider Silica (SiO 2 ) - Alumina (Al 2 O 3 ) system. Phase diagram shows: mullite, alumina, and crystobalite (made up of SiO 2 ) tetrahedra as candidate refractories. 6 APPLICATION: REFRACTORIES
Die blanks: --Need wear resistant properties! 7 Die surface: --4 m polycrystalline diamond particles that are sintered on to a cemented tungsten carbide substrate. --polycrystalline diamond helps control fracture and gives uniform hardness in all directions. APPLICATION: DIE BLANKS
Steels: increase TS, hardness (and cost) by adding -C (low alloy steels) -Cr, V, Ni, Mo, W (high alloy steels) -Ductility usually decreases w/ additions Nonferrous: -Cu, Al, Ti, Mg Refractory, and noble metals Basic categories of ceramics: -Glasses -Clay products -Refactories -Cements -Advanced ceramics 10 SUMMARY