5. Conclusions Evalutio
The microstructures of the base alloys consist of three phases. The brittle y, — phase is a vonz tik
intermetallic compound ( Cug Als ) with a complex cubic structure similar to the y — phase in ha
brasses. This phase exists in form of seams at the former p — grainboundaries and in form of
rosette — like particles inside of the former B — grains. Additional the ordered orthorhombic B, Als vor CA
— phase ( Cu; Al) and finedisperse x — segregations ( Fe Al) appear in the microstructures. 8 Fisen
In the microstructure of the spray formed and hot pressed alloy a banded structure of the ERE
former B — grains exists in a longitudinal section. The y, — particles are smaller and have a sind versch
finer distribution compared with the spray formed state. Pires
By oil quenching of small specimens from the § — region it is possible, to stabilize almost Laufe der
completly the ordered bcc ß2 - phase ( Cu Al). The microstructures of the betatized alloys are ad bz
coarse — grained. In the spray formed alloy the grain size of the 3, — phase is smaller Präparanıc
compared with the cast alloy.
The annealing of the betatized specimens at temperatures between 500°C and 700°C produces Es entwick
the decomposition of the metastable ß2 — phase into several product phases. In the annealed vermutlich
microstructures the y, — phase is the predominant part. The arrangement of this phase in the Danach €!
microstructure depend on the annealing temperature. Low annealing temperatures produce Dinosaun
very fine particles of the y, — phase. At higher annealing temperatures, for example 700°C, a Im Bild
microstructure is formed similar to the microstructure of the base alloy. The y, — phase exists makroskof
in form of seams at the former ß — grainboundaries and in form of rosette — like particles Vergrößer
inside of the former 3 — grains. The orthorhombic f; — phase and precipitations of the x — nies
phase are further parts of the annealed microstructures. -
Literature Hilfsmitte
Knochen,
1. Deutsches Kupfer — Institut, Informationsdruck, Kupfer — Aluminium — Legierungen, Knochen,
Düsseldorf, zu erkent
2. Keller, K., Umformwerkzeuge aus Aluminium — Mehrstoffbronzen, Ah
Mitt. Forschungsgesellschaft Blechverarbeitung, 1965, Nr.5 / 6, 5.96 — 101
+ Stock, D., Sprühkompaktieren von Kupferlegierungen im industriellen Maßstab Die Evolt
Zeitschr.Metall 49 ( 1995 ) S.737 — 739 Menschhe
} Hansmann, S., Neue Cu — Werkstoffe durch Sprühkompaktieren, Bronze bi
Zeitschr.Metall 53 ( 1999) S.182 — 186 noch viel
5. Ohla, K., Benkißer, G., The microstructures in spray formed complex aluminium und Waff
bronzes, EUROMET 2000, Poster Bild 11
6. Brezina, P., Heat treatment of complex aluminium bronzes, Intern.Metals Rev. 82 ( Präparatir
1981 ) 5.71 — 120 schen
? Kainuma, R., S.Takahashi and K.Ishida, Thermoelastic martensite and shape memory
effect in ductile Cu — Al — Mn alloys, Es wurde
Metallurgical and Materials Trans. A 27A ( 1996 ) S.2187 — 2195 " Geld
Münzen
Kupferles
Entwick!
Neer
Me
CRs
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