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12 Cards in this Set
- Front
- Back
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Process of compression of finely divided metal powder into a briquette of desired shape. Then heated not melted to form a metallurgic bond between the particles. |
Powder metallurgy |
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The basic conventional process of making p/m parts consists of two basic steps |
Compacting (molding) Sintering (heating) |
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Loose powder placed in a die and then compacted between two punches. Gives an exact shape. |
Compacting |
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The briquette is heated in an appropriate atmosphere to a temp high enough to cause the powder particles to bond together by solid state diffusion and to homogenize any alloy constituents in the powder. (Powder metallurgy) |
Sintering |
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Three most important methods of producing metal powders are? |
-Atomization(spray) -Chemical methods(chemical reduction) -electrolytic process(anode + cathode) |
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Manufactures often choose p/m over other manufacturering methods because of the following characteristics: |
-superior engineered micro structures and properties with precise control -consistent properties and quality -controlled porosity for filters and self-lubrication -very low scrap loss |
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More p/m products and their uses |
-wide variety of shape designs -unlimited choice of alloys and composites -low cost, high volume production -little or no machining required -close dimensional tolerances -good surfaces finishes |
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Disadvantages of p/m |
-Lower corrosion resistance than solid metals because of larger internal surface(porous) -tend to have reduced plastic properties (ductility and impact strength) compared with conventionally produced metals |
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The cutting tool may be held stationary and moved across a rotating workpiece as on a Or a rigidly help workpiece may move into a rotating cutting tool as on a milling machine |
Engine lathe |
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High speed steel is |
-less expensive -longer tool life, able to be resharpened -because of its versatility and low cost it is most commonly used x-31 |
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Carbide cutting tools |
-most cutting tools for production are made from tungsten carbide -can machine at higher temps than HSS. -cutting speed three to four times faster than HSS. -most carbide tools are thro away inserts that have several indexable cutting edges. And can be clamped into different tool holders. |
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Ceramic cutting tools |
Have better hot hardness than carbide. Often used to machine hard workpiece materials - much higher speeds than carbide -cannot endure impact of heavy interrupted cuts -several indexable cutting edges. |
