Chapter 5 Nonferrous Heavy Alloys

1
Chapter 5Nonferrous Heavy Alloys

• 1302 310
• Engineering Metallurgy
• Lecturer Dr.Sukangkana Lee

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1. The Superalloys

• Superalloys ??????????????????????????????????????
  ??? ???????????????????????? ?????????????????????
  ???????? ?????? 1000 ?C ?????????????????????????
  ? ???????????????
• ???????????????????? ???????????
  ?????????????????????
• ?????????????? ????????????
• ?????????????????
• ?????????????????????????????? ?????????????

3

• ?.?. 1930-1940 ???? ??????????????????????????????
  ????????????????????????? (Heat resistant
  materials) ???????????????????????????????????????
  ???? ?????????????????????????? 730-1370 ?C

4
1100 ?C
650-980 ?C
1100 ?C
760 ?C
5

• ???????? Ni ????????????????? 1455 ?C ???????? Cr
  ????????????????? 1875 ?C ??????????? 8020
  ???????? Nicrome ?????????????????????????????
  
• ??????? ????? ??????????? Ti ???? Nicrome ?????
  0.3 wt ??? C ?????? 0.1 ???????????????????????
  ??? ???????????? Nimonic 75 ???????????
  ??????????????????????? Superalloy ????????

6
Titanium Nickel Steel Aluminium Composites
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???????????????? Superalloys

• ???????????????????????????? ????????????????????
  ???????????????? FCC ?????????????????????
  Austenitic ????????????????????????????
  ??????????????????? ??????????????????????????????
  ???????????????????????? BCC ?????????????????
  FCC ??????????????? Precipitate ??? solid
  solution ??????????

8
100 hour rupture stress For Nickel-base
alloy 713C, IN-738, R80, B-1900, In-100
Stress, ksi
100 hour rupture stress For Cobalt-base
alloy HS-31, WI-52, FSX 414, Mar M 509
Temperature, F
9
Metal Crystal structure Melting point ?C Density g/cm3 Thermal Expansion ?m/mK Thermal conductivity W/mK Phase stability
Co HCP 1495 8.90 13 100 2
Ni FCC 1455 8.90 13.4 90.9 1(most stable)
Fe BCC 1538 7.74 11.8 80.4 4(least stable)
Cr BCC 1907 7.20 4.9 93.9 3
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??????? Superalloy

• ????????????????? 3 ???????
• Ni-based Superalloys
• Ni-Fe Superalloys
• Co-based Superalloys

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Ni-based Superalloys

• ???? Nickel ???????????????????
  ????????????????????????? ???
• Cr ?????????? 20 wt ?????????????????????????????
  ???????????? Solid solution hardening
• Ti and Al ????????????????????????????????????????
  ??????????????? precipitation hardening
  ??????????????????? Ni3(Al,Ti)
• ????? ???? Mo, Co, Nb and B

12

• ???????? Ni-based Superalloys ???????????? 100
  ???????? ?????????????????????????????????????????
  ??????????? ??? Inconel X-75, Rene 41 and
  Nimonic 90 ???????

13
Ni-Fe Superalloys

• Superalloys ??????? ???? Nickel
  ??????????????????? ?????? 25-60 wt ??? Fe 15-60
  wt ?????????????????????? ??? ???????????????????
  ??????????? ??????????????????????????????????
  650-850 ?C ????????

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• ???????????????????? ???
• Cr ?????? 15-28 wt ??????????????????????????????
  ??
• Mo ?????? 1-6 wt ????????????????????????????
  Solid solution hardening
• ????????????????????????????????? ?????????????
  Ti and Al ????????????? ????????? Ni3(Al,Ti)

15
Co-based Superalloys

• ???? Cobalt ?????????????????????? 1495 ?C
  ??????????????????? ?????? 50 wt ??? Cr ??????
  25 wt ????????
• ???????????????????? FCC ?????????????????????????
  ????????????????? Cr ??????????? ?????????????
  Carbide ????????? ????????????????????????????????
  ????????????????????????????
• ????????????????????????? ???????????????????????
  ????? ?????????????

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3. Heat Treatment of Superalloys

• Superalloys ????????????? ??????????? Solution
  treatment ????????????????? 1040-1230 ?C
  ??????????? Ageing ?????????????? ??????????
  Ageing ?????????????????? ?????? 760 ?C
  ?????????????????????????????
• ??????????
• ????????????????????????? ?? ????????????
  ???????????????????????????? dislocation
  ????????? ??? ?? ???????????????? FCC
  ???????????????????? A3B ???? Ni3(Al,Ti),
  (Ni,Co)3(Al,Ti) ???????

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(No Transcript)
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4. Manufacturing Process

• ??????? Superalloys ???????????????
  ??????????????
• 1. ????????????? (Conventional casting)
• 2. ?????????????????? (directional
  Solidification) ??????????????????????????????????
  ????????????????????????????? Columnar grain
  ??????????????????????????????????????

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• ?????????????????? ???????? ????????????? ?????
• ???????????????????????????? ?????????????????????
  ?????????????????????????????
• ????????????????????????????????
• ???????????????????????????????
• ???????? Precipitate ??????????
• ??????????????? superalloys ????????????????
  ??????????????????? ?????? ???????????????????????
  ????? ??????????????????????????????
  ?????????????????????????????????????????????

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Direct Chill Method
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Adaptation of Stockbarger method
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• ???????????????????????????? ???
• ???????
• ??????? precipitate ???????????????? ???
• ???????????????????????????????????????
  ??????????????????? Oxidation ???
  ???????????????????
• ????????????????????????????????????

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• ??????? ????????????????? ???????????????????
  (Single grain) ???????????????????????????????????
  ?????????????????????
• ????????????????????? ????????????????????????????
  ???????? ???????????????????????????
• ??????????????????? ?????????????????????????????
  ?????? ??????????????????????????????????
  ????????????????????????????????

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???????

• ???????????????????????????????????????? 3-4 ????
  ??????????????????????????????????????????????????
  ?????????
• ??????????????????????????????????????????????????
  ???? 001 ???????? ??????????????????????????????
  ?????????

001
???????
?????????????????
25
(No Transcript)
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Single Crystal alloy
Directional Solidified columnar
Creep Strain
Conventional Uniform equiaxed
Time
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5. Copper and Copper alloys

• Leaded red brasses ???????????????????????????????
  ???????????????? ?????????????????? ?????????
  ???????????????????????????????????? 40
• Leaded semi-red brasses ??????????????????????????
  ??? ???????????????????????????
• Tin bronzes ???????????????????????????????? ????
  ????? ???????????????????????????? 10
  ????????????????????? ??????????????????????????

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• Leaded tin bronzes ???? bronze ???????????????????
  ?????? 0.5 ?????????? ???????????? ??? ???????
  ???????????? ????????????????????????
  ????????????????????????????? ????????????????????
  ???? ??? ????????????????????????????????
• High-leaded tin bronzes ???? bronze
  ????????????????????????????????
  ?????????????????????????????????
  ?????????????????????????????????

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????????????????? (Alloying element) ???
?????????????

• Zinc ?????????????????????????????????????????????
  ???????????????? ????????????????????????????
  ???? Solid-solution strengthening
• Zn ????????????????????????? Cu ??????? 32.5
  ??????????????????????????????????????? ?-phase
  ???????????????????????????????
• ????????? Zn ??????????????????????????
  ????????????????? ?????????

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• Tin ????? ????????????????????????????????????????
  ??????????????????????????????????????????????????
  ??????????????? ??? ????????????????????????????
• ????????????????????????? 10 ???????????????????
  ???????? ?????????????????????? non-equilibrium
  freezing ??????????????????????? ?????????????
  ?-phase ???????????????????????????????????
  ??????????????????????????????????????????????????
  ???????????????????????????????
  ??????????????????? coring
• ?????????????????????????? ????????????????????
  ????????????????????????????? ????????????????????
  ?? ?-phase ?????????????????? ????????????????????
  ????????????????????????

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• Lead ?????? ??????????????????????????????
  ??????????????????????????? ??????????????????????
  ??????????? ??????????????????????????????????????
  ? strength ??? elongation ???????
• Other elements ???? Aluminium Manganese Silicon
  and Iron ??????????? strength ?????????????
  ?????????????????????????????? ???????????????????
  ?????????????????????????????????????
  2-7??????????

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Heat treatment of copper alloys

• copper and most copper alloys are homogeneous
  single phase
• they are not susceptible to heat treatment and
  their strength may be altered only by cold
  working
• There are two types of temper Cold-worked and
  Annealed.

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Description Reduction by cold work Reduction by cold work
Description Strip Wire
¼ hard 10.9 20.7
Half hard 20.7 37.1
¾ hard 29.4 50.0
Hard 37.1 60.5
Extra Hard 50.0 75.0
Spring 60.5 84.4
Extra Spring 68.7 90.2
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Annealed temper
Grain size (mm) Recommended for
0.015 Slight forming
0.025 Easy forming
0.035 Good drawing and polishing
0.050 Heavy drawing
0.100 Severe draws
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1) Copper-Zinc (brass) at 30Zn70Cu,

• Slow cooling rate
• will allow the equilibrium structure solid
  solution a phase (fcc structure).
• The a brass are soft and ductile (greater
  ductility than pure copper) and capable for cold
  work.

Annealed, 75x
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Cu-Zn
L???L??
L???L??????
37

• Rapid cooling rate
• will not allow the equilibrium structure.
• The a phase will be rich in copper and the last
  liquid will be rich in Zn and undergo a
  Peritectic reaction a L?ß at grain boundary.

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2) Copper-Zinc (brass) at 40Zn60Cu,

• Slow cooling rate
• The liquid will solidified as the equilibrium
  phase a ß?
• ß? has bcc structure and much stronger than the
  a-phase and has a lower ductility.
• This structure (a ß?) therefore is difficult to
  cold work but can be hot work.

?
?
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Typical precipitation hardening of
copper-Beryllium alloy