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MaterialsMaterials

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Engineering MaterialsEngineering Materials

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Material PropertiesMaterial Properties

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MetalsMetals

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Solidification of Molten MetalSolidification of Molten Metal

Figure 1.11 Schematic illustration of the stages during solidification of molten metal; each small square represents a unit cell. (a) Nucleation of crystals at random sites in the molten metal; note that the crystallographic orientation of each site is different. (b) and (c) Growth of crystals as solidification continues. (d) Solidified metal, showing individual grains and grain boundaries; note the different angles at which neighboring grains meet each other.

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Grain StructureGrain Structure

Figure 4.3 (a) Schematic illustration of grains, grain boundaries, and particles dispersed throughout the structure of a two-phase system, such as a lead-copper alloy. The grains represent lead in solid solution in copper, and the particles are lead as a second phase. (b) Schematic illustration of a two-phase system consisting of two sets of grains: dark and light. The dark and the light grains have separate compositions and properties.

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Microstructure for Cast IronsMicrostructure for Cast Irons

Figure 4.13 Microstructure for cast irons. Magnification: 100x. (a) Ferritic gray iron with graphite flakes. (b) Ferritic ductile iron (nodular iron) with graphite in nodular form. (c) Ferritic malleable iron. This cast iron solidified as white cast iron with the carbon present as cementite and was heat treated to graphitize the carbon.

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Cold, Warm and Hot WorkingCold, Warm and Hot Working

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Mechanical PropertiesMechanical Properties

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Stress-strain CurveStress-strain Curve

Figure 2.2 A typical stress-strain curve obtained from a tension test, showing various features

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Other Mechanical PropertiesOther Mechanical Properties

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Hardness-testing MethodsHardness-testing Methods

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Brinnel Testing IndentationBrinnel Testing Indentation

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Strength versus TemperatureStrength versus Temperature

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Heat Treating (Ch.4)Heat Treating (Ch.4)

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Hardness and TimeHardness and Time

Figure 4.16 Hardness of tempered martensite as a function of tempering time for the 1080 steel quenched to 65 HRC. Hardness decreases because the carbide particles coalesce and grow in size, thereby increasing the interparticle distance of the softer ferrite.

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Gear Teeth Cross-sectionGear Teeth Cross-section

Figure 4.1 Cross-section of gear teeth showing induction-hardened surfaces. Source: Courtesy of TOCCO Div., Park-Ohio Industries, Inc.

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Heat Treatment ProcessesHeat Treatment Processes

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Heat Treatment Processes (cont.)Heat Treatment Processes (cont.)

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MetalsMetals

Irons• Cast irons• Steels• Stainless steel• Tool steels

Non-irons• Aluminum• Copper• Magnesium• Nickel• Titanium

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Nonferrous Metals and AlloysNonferrous Metals and Alloys

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PolymersPolymers

ThermoplasticsThermosetsElastomers

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Properties of PlasticsProperties of Plastics

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Ceramics and GraphiteCeramics and Graphite

GlassMineralBrickMineralDiamond

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Ceramics in ProductsCeramics in Products

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Ceramic ComponentsCeramic Components

Figure 8.1 A variety of ceramic components. (a) High-strength alumina for high-temperature applications. (b) Gas-turbine rotors made of silicon nitride. Source: Courtesy of Wesgo Div., GTE.

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CompositesComposites

Reinforced plasticsCeramic-basedPlywood and particleboard

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CompositesComposites

Figure 9.2 Schematic illustration of methods of reinforcing plastics (matrix) with (a) particles, (b) short or long fibers or flakes, and (c) continuous fibers. The laminate structures shown in (d) can be produced from layers of continuous fibers or sandwich structures using a foam or honeycomb core (see also Fig. 16.50).

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Boeing 757-200Boeing 757-200

Figure 9.1 Application of advanced composite materials in Boeing 757-200 commercial aircraft. Source: Courtesy of Boeing Commercial Airplane Company.

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Changing the Nature of Materials

Changing the Nature of Materials

Mix/blend/growProcess• Work

» Hot» Warm» Cold

Heat treatment, anneal, hardening, quenchLayer

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SelectionSelection

How do we select materials?Resources and Standards• Reference books• Internet

» http://www.asminternational.org/

Software (Cambridge Engineering Selector)

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American Society of MaterialsAmerican Society of Materials