Copper

1
(No Transcript)
2
Chapter 18

• Copper

Copper Manufacturing Copper Alloys Copper
Fabrication Copper Alloy Properties
3

• Copper is extracted chiefly from sulfide ores and
  processed into specific finished forms.

4

• To a large extent, the foundry properties of
  copper alloys depend on whether they are
  low-shrinkage or high-shrinkage alloys.

5

• Annealing heat treatments are used to homogenize,
  soften, or stress relieve copper alloys.

6

• Copper alloys are designated in the Unified
  Numbering System (UNS) for metals and alloys.

7

• Temper designations indicate mechanical working
  and heat treatment conditions of copper alloys.

8

• Each system exhibits different properties that
  are characteristic of that system.

9

• The microstructure of tough pitch copper heated
  in hydrogen for 2 min. at 850C (1560F) shows
  black voids, which correspond to porosity created
  by pockets of water vapor (steam).

10

• Aging develops (CuCo)Be berylide inclusions in
  the copper-rich matrix of beryllium coppers.

11

• Low-beryllium coppers and high-beryllium coppers
  are the two groups of beryllium coppers.

12

• The selected aging temperature for beryllium
  coppers depends on the desired properties and the
  amount of prior cold work.

13

• The microstructure of leaded beta brass shows a
  dispersion of lead particles.

14

• Manganese bronzes exhibit a duplex microstructure.

15

• The copper end of the copper-tin phase diagram
  shows a wide temperature range between the
  liquidus and the solidus, making these alloys
  highly susceptible to coring.

16

• The copper end of the copper-aluminum phase
  diagram indicates that alloys up to approximately
  8 Al are single phase.

17

• The microstructure of cast duplex aluminum
  bronzes may be altered by the rate of cooling.

18

• The microstructure of nickel-aluminum bronzes
  shows kappa phase and iron rounds.

19

• The copper-silicon phase diagram indicates that
  alloys with up to 5 Si are single phase because
  the eutectoid reaction is very sluggish.

20

• The copper-nickel phase diagram indicates that
  copper and nickel are soluble in one another at
  all compositions and form a single-phase
  microstructure.

21

• Copper alloys are formed by a wide variety of
  processes.

22

• Grain size is the major property that determines
  drawability and stretching formability of coppers
  and single-phase copper alloys.

23

• Copper alloys may be ranked according to
  forgeability.

24

• Welding filler metals used for welding copper and
  copper alloys may be covered electrodes or bare
  wire.

25

• Silver alloy and copper-phosphorus filler metals
  are commonly used to braze copper alloys.

26

• Cast copper alloys may be divided into three
  groups according to ease of machining.