PRECIPITATION HARDENING

UNIVERSITAS JENDERAL ACHMAD

YANI

BANDUNG

PENDAHULUANPresipitation 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

PENDAHULUAN

PENDAHULUAN

Skematik temperatur tehadap waktu

Pengaruh waktu aging terhadap sifat mekanik

gambar 2.16. Skematik pengaruh temperatur pada presipitat Al-Cu. (a) Garis solvus

metastabil dan (b) waktu memulai pembentukan presipitat

MEKANISME PENGUATAN

Interaksi Dislokasi dengan Presipitat

dislokasiPresipitat

Cutting

MEKANISME PENGUATAN

Bowing

dislokasi

Paduan yang bisa dikeraskan dengan proses presipitation

hardening

DIAGRAM FASA Al-Cu

Contoh proses precipitation hardening Al-

Cu

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.

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,

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.)

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.

SEKIAN

“ Niscaya Allah akan meninggikan orang-orang yang beriman

diantaramu dan orang-orang yang diberi ilmu pengetahuan beberapa

derajat”

(Q.S. Al-Mujadilah: 11)