Precipitation hardening is a process of strengthening metal alloys by uniformly dispersing fine particles through aging (precipitation) after solution treatment and quenching. It requires the alloy to be a metal alloy and for its solid solubility limit to decrease with temperature. During aging, dispersed particles interact with dislocations to strengthen the alloy by cutting, bowing, and decorating grain boundaries. Common alloys strengthened through precipitation hardening include aluminum-copper alloys.

1. PRECIPITATION HARDENING
UNIVERSITAS JENDERAL ACHMAD
YANI
BANDUNG

2. PENDAHULUAN
Presipitation Hardening adalah proses pengerasan paduan logam dengan
menyebarkan partikel-partikel halus secara merata. dengan proses penuaan
(aging) yang sebelumnya telah mengalami proses pelarutan ( solution treatment)
dan pencelupan (quenching)
Syarat Presipitation Hardening :
•Merupakan Logam paduan
•Batas kelarutan padat harus berkurang dengan turunnya temperatur

3. PENDAHULUAN

4. PENDAHULUAN
Skematik temperatur tehadap waktu

5. Pengaruh waktu aging terhadap sifat mekanik

6. gambar 2.16. Skematik pengaruh temperatur pada presipitat Al-Cu. (a) Garis solvus
metastabil dan (b) waktu memulai pembentukan presipitat

7. MEKANISME PENGUATAN
 Interaksi Dislokasi dengan Presipitat
Cutting
dislokasi
Presipitat

8. MEKANISME PENGUATAN
 Bowing
dislokasi

9. Paduan yang bisa dikeraskan dengan proses presipitation

10. DIAGRAM FASA Al-Cu

11. Contoh proses precipitation hardening Al-

12. Schematic depiction of several stages in the formation of the equilibrium
precipitate ( ) phase. (a) A supersaturated solid solution. (b) A
transition, precipitate phase. (c) The equilibrium u phase, within the α-
matrix phase.

13. The precipitation hardening characteristics of a 2014
aluminum alloy (0.9 wt% Si, 4.4 wt% Cu, 0.8 wt% Mn, 0.5
wt% Mg) at four different aging temperatures: yield strength,

14. A transmission electron micrograph showing the microstructure of a 7150-T651
aluminum alloy (6.2Zn, 2.3Cu, 2.3Mg, 0.12Zr, the balance Al) that has been
precipitation hardened. The light matrix phase in the micrograph is an
aluminum solid solution. The majority of the small plate-shaped dark precipitate
particles are a transition phase, the remainder being the equilibrium (MgZn2)
phase. Note that grain boundaries are “decorated” by some of these particles.
(Courtesy of G. H. Narayanan and A. G. Miller, Boeing Commercial Airplane
Company.)

15. DAFTAR PUSTAKA
 William D. Callister, Jr. “Materials Science and Engineering 7th” , John
Wiley & Sons, Inc. 2007.
 R. E. Smallman and R. J. Bishop, “Modern Physical Metallurgy and
Materials Engineering 6th” , Butterworth-Heinemann, 1999.
 D.A. Porter and K.E.Easterling, “Phase Transformations in Metals and
Alloys 2nd ” chapman & Hall, 1992.
 William F.Smith “ Principles of Materials Science and Engineering 3rd ”
McGraw-Hill Inc, 1993.

16. SEKIAN
“ Niscaya Allah akan meninggikan orang-orang yang beriman
diantaramu dan orang-orang yang diberi ilmu pengetahuan beberapa
derajat”
(Q.S. Al-Mujadilah: 11)