Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys
We investigated alloys differing in chemical composition as well as by the regimes of heat treatment in the initial state (before heat cycling). Heat cycling consisted in heating blanks of a copper-manganese alloy to 200-850° C with subsequent cooling at rates of 5 to 150-200° C/sec. After the heat...
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Інститут проблем міцності ім. Г.С. Писаренко НАН України
1985
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| Cite this: | Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys / B.S. Chaikovskii, G.Ya. Yaroslavskii, L.A. Bocharova // Проблемы прочности. — 1985. — № 8. — С. 1121-1124. — Бібліогр.: 3 назв. — англ. |
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nasplib_isofts_kiev_ua-123456789-1828692025-02-09T15:18:29Z Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys Влияние температур нагрева и скоростей охлаждения на демпфирующие свойства сплавов на марганцевомедной основе Chaikovskii, B.S. Yaroslavskii, G.Ya. Bocharova, L.A. Scientific-technical section We investigated alloys differing in chemical composition as well as by the regimes of heat treatment in the initial state (before heat cycling). Heat cycling consisted in heating blanks of a copper-manganese alloy to 200-850° C with subsequent cooling at rates of 5 to 150-200° C/sec. After the heat cycling, specimens for investigating the damping properties were made from the blanks. 1985 Article Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys / B.S. Chaikovskii, G.Ya. Yaroslavskii, L.A. Bocharova // Проблемы прочности. — 1985. — № 8. — С. 1121-1124. — Бібліогр.: 3 назв. — англ. 0556-171X https://nasplib.isofts.kiev.ua/handle/123456789/182869 539.67;620.178 en Проблемы прочности application/pdf Інститут проблем міцності ім. Г.С. Писаренко НАН України |
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Scientific-technical section Scientific-technical section Chaikovskii, B.S. Yaroslavskii, G.Ya. Bocharova, L.A. Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys Проблемы прочности |
| description |
We investigated alloys differing in chemical composition as well as by the regimes of heat treatment in the initial state (before heat cycling). Heat cycling consisted in heating blanks of a copper-manganese alloy to 200-850° C with subsequent cooling at rates of 5 to 150-200° C/sec. After the heat cycling, specimens for investigating the damping properties were made from the blanks. |
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Article |
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Chaikovskii, B.S. Yaroslavskii, G.Ya. Bocharova, L.A. |
| author_facet |
Chaikovskii, B.S. Yaroslavskii, G.Ya. Bocharova, L.A. |
| author_sort |
Chaikovskii, B.S. |
| title |
Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
| title_short |
Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
| title_full |
Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
| title_fullStr |
Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
| title_full_unstemmed |
Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
| title_sort |
effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys |
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Інститут проблем міцності ім. Г.С. Писаренко НАН України |
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1985 |
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Scientific-technical section |
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https://nasplib.isofts.kiev.ua/handle/123456789/182869 |
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Effect of the peak temperatures and of the cooling rate on the damping properties of manganese-copper base alloys / B.S. Chaikovskii, G.Ya. Yaroslavskii, L.A. Bocharova // Проблемы прочности. — 1985. — № 8. — С. 1121-1124. — Бібліогр.: 3 назв. — англ. |
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Проблемы прочности |
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| fulltext |
The method used here reliably reflects the effect of decarbonization on the strength of
the cylindrical walls of pressure vessels, as was confirmed in tests: experimental cylinders
free of any defects that might affect their strength had breaking pressures which were con-
sistent with the values calculated by the above method. The cylinders fractured through the
cylindrical wails.
1.
2.
LITERATL~E CITED
Handbook of Kotlonadzor Projects [in Russian], Energiya, Moscow (1974).
V. P. Shirshov, "Prediction of fracture of thin-wailed pressure vessels," Probl. Prochn.,
No. 6, 60-63 (1982).
EFFECT OF THE PEAK TEMPERATURES AND OF THE COOLING
RATE ON THE DA~ING PROPERTIES OF MANGANESE--
COPPER BASE ALLOYS
B. S. Chaikovskii, G. Ya. Yaroslavskii,
L. A. Bocharova, O. T. Bashta,
and V. V. Matveev
UDC 539.67;620.178
It was shown in [i, 2] that alloys of the system Mn--C~Zn are distinguished by a favor-
able combination of high damping ability, strength, and ductility. It is, however, very im-
portant that actual products made of these alloys have a high level of energy losses.
When structures are produced, the alloy may be subjected to various thermal effects
(e.g., in consequence of the technological operation of welding) which may change its
initial damping properties.
To determine the effect of various peak temperatures and cooling rates on the damping
ability of copper-manganese alloys at normal temperature, we carried out the respective
tests on an installation KD-I [3].
We investigated alloys differing in chemical composition as well as by the regimes of
heat treatment in the initial state (before heat cycling). Heat cycling consisted in heat-
ing blanks of a copper-manganese alloy to 200-850~ with subsequent cooling at rates of 5 to
150-200~ After the heat cycling, specimens for investigating the damping properties
were made from the blanks.
Heat cycling was applied to alloys in different initial states (cast, hardened, hard-
ened + tempered). The chemical composition of the alloys concerned is presented in Table i.
The investigations showed (Fig. i) that heating from 200 to 400~ and subsequent cool-
ing at rates from 5 to 150-200~ has practically no effect on the damping ability of the
alloy in the cast state. Further heating to 600 or 850~ with the same cooling rates causes
a noticeable lowering of the level of the dissipative properties of the alloy (by a factor
of 1.5-2).
The cooling rate has practically no effect on the damping properties of the investi-
gated alloys in the cast state after they have been heated to between 200 and 850~ How-
ever, the peak temperature to which the alloy is heated causes a substantial change of its
dissipative properties independently of the cooling rate. The greatest change in the damp-
ing ability of the alloys in the cast state is found when they are heated to 600~ or more.
Alloys of the system Mn-Cu--Zn in the cast state are characterized by general inhomo-
geneity and liquation in regard to the chemical composition, and the cooling conditions have
the effect that the structure of the alloys, together with y(fcc)-phase, also contains the
tetragonal yt-phase whose presence is decisive for the high damping of these alloys. The
yt-phase is distributed nonuniformly throughout the bulk, and in consequence damping is not
Institute of Strength Problems, Academy of Sciences of the Ukrainian SSR. Kiev Poly-
technic Institute, Kiev, Leningrad. Translated from Problemy Prochnosti, No. 8, pp. 74-77,
August, 1985. Original article submitted June 14, 1984.
0039-2316/85/1708-1121509.50 O 1986 Plenum Publishing Corporation 1121
TABLE i. Chemical Composition, %, of the
Investigated Alloys
Alloy
N o ,
Mn
53.55
54.56
52.77
54,85
53.60
52.94
53,27
52.61
0.09
0.42
0.07
0.06
0.11
0.04
0.05
0.04
C
0.17
0,21
0.04
0,15
0,04
0,03
0.04
0,04
Zn
7.8
6,77
9,72
7,0
9,94
11.21
I0,67
I 1,29
C u
Remainder
)
]D
+.~1 ' !
3
2,2 q.O 50 80 ~00 6,MPa
Fig. i. Dependence of the vibration decrement
of specimens of alloy No. 1 on the amplitude
of the cyclic stresses in the cast state (i)
and also after heating to 200~ (2), 400~ (3),
600~ (4), 850~ (5) and cooling at rates from
5 to 150~
,~?/o r - - l" - -
i l
+.i ,_ _ ,_ 1
"+/ .~, /
,+ L . . . . . . . . ~____~.m~_ a__ !
[ . . . , - " ~ +
,,+_ . , ,
+ 22 .2 63 S2 :03 5. M P ~
Fig. 2. Dependence of the vibration decre-
ment of specimens of alloy No. 3 on the amp-
litude of the cyclic stresses after the full
heat treatment regime (curve i) and also
after additional heating to 600~ with sub-
sequent cooling at rates of 35-50~
(curve 2), 5 and 150-200~ (curve 3).
optimal. Heating to 200~ practically does not change the structure of the cast alloy but
it causes relaxation of the internal stresses arising in consequence of the nonuniform
cooling of all volumes of the material after casting, and this leads to a slight lowering
of the damping ability. Heating to 400~ also causes relaxation of the internal stresses
in the alloy, and this manifests itself in a slightly lower damping ability of the alloy.
1122
I I ;
':' + F - - + - ~ - . . . . . ~ - - , : ~ - - - +
I ,<,+ I / ' + + + I + :
~ + ' I ' ' - - . . . . 4 . . . . . -
+ I / _ Z - : ' : ; : �9
",+~I~-----. + --- ]+ . . . . . + - - - A - - s ,
i ' , ' :
I "+ '+
" ' I ', [
: , , I ] i
0 ~$ ~C ~0 80 I00 o, M P a
Fig. 3
16
t2
9
- -
! [ 1
<": ............ i . . . . . .
, I
i i ,
20 "~0 50 80 :00 ~ M P a
Fig. 4
Fig. 3. Dependence of the vibration decrement of specimens of alloy No. 3 on the
amplitude of the cyclic stresses after hardening (curve i), and also after addi-
tional heating to 400~ with subsequent cooling at rates of 35-50~ and 150-
200~ (curve 2), 5~ (curve 3).
Fig. 4. Dependence of the vibration decrement on the amplitude of the cyclic
stresses for specimens of alloy No. 3 subjected to tempering at 400~ 4 h after
being heated to 600~ and cooled at different rates: i) hardening + tempering
(without heat cycling); 2) cooling at the rate of 5~ 3) 150-200~ 4)
35-50~
It was shown previously [i] that the temperature of 400~ is close to the critical
temperature at which spinodal decomposition of the y(fcc)-solid solution occurs, i.e., we
find segregation of the atoms of the solid solution (of manganese and copper) and the forma-
tion of regions enriched with and deficient in manganese. In regions enriched with mangan-
ese, at temperatures close to 400~ yt-phase is bound to form, and consequently also twins
which cause high damping of the alloy.
As a result of rapid heating to 400~ and fairly high cooling rates at which the process
of heat cycling proceeds, the yt-phase in reality did not manage to form, and the damping
properties did not increase; on the contrary, in consequence of the reduced internal stresses,
they even decreased slightly.
When the temperature is raised to more than 400~ (to 600 or 850~ spinodal decom-
position of the y-solid solution with formation of yt-phase is impossible. Heating to such
high temperatures possibly leads to partial decomposition of the Tt-phase (Yt § Y + e Mn)
contained in the cast alloy, and this causes a substantial lowering of the dissipative
properties of the alloy.
Qualitatively analogous results were obtained in the investigation of the effect of
different heat cycling regimes on the dissipative properties of alloys that had been sub-
Jected to the full regime of heat treatment, which consisted of hardening at 800~ 4 h in
water, and tempering at 400~ for 4 h with cooling in air. Heating to 400~ and cooling at
rates of 5 to 150-200~ had no substantial effect on the damping ability of the in-
vestigated alloys.
Raising the temperature to 600~ with subsequent cooling at rates from 5 to 150-200~
sec lowers the level of energy losses of alloys that had been subjected to the full heat
treatment regime by approximately two orders of magnitude. As an example, Fig. 2 presents
the results of investigations of the amplitude dependence of the vibration decrement for
specimens of alloy No. 3 (Table i) in the initial state (after the full heat-treatment
regime), and also after being heated to 600~ with subsequent cooling at rates of 35-50~
sec, 5 and 150-200~ The cause of such an abrupt decrease of damping ability of the
fully heated-treated alloy, as well as of the alloy after casting, is the same: heating to
temperatures above 400~ causes disintegration of the yt-phase (Yt § Y + ~ Mn), which en-
sures a high level of energy losses of the alloy.
1123
Heating to 850~ with subsequent cooling at rates from 5 to 150-200~ leads to a
substantial decrease (by a factor of approximately five) of the damping properties of the
alloys compared with the initial state; nevertheless, the decrease is somewhat smaller than
after heating to 600~ with subsequent cooling at the same rates.
If after al] heat-cycling regimes of the investigated cast and fully heat-treated alloys
they are subjected to complete heat treatment (hardening at 800~ 4 h in water and tempera-
ture at 400~ for 4 h with cooling in air), the damping ability of the examined alloys can
be raised or restored to the initial level (curve 1 in Fig. 2).
Since real finished structures cannot be hardened and tempered because of the change of
their geometric dimensions and shape, it is also inadvisable to use a production technology
involving the heating of cast and fully heat-treated alloys to temperatures above 400~ (e.g.,
by welding, etc.) because that might cause an abrupt decrease of the damping ability of the
alloy.
From the practical point of view, the most interesting results were obtained in the in-
vestigation of the effect of heat cycling on the damping ability of alloys in the initial
state after hardening. X-ray structure analysis showed that hardening fixes the y(fcc)-phase,
and there are practically no microtwins which would be responsible for the high level of
damping in alloys of the system Mn-Cu--Zn. The level of energy dissipation in hardened alloys
of this system is therefore very low (curve 1 in Fig. 3) and represents in fact background
internal friction. Heating to 200~ with subsequent cooling at rates from 5 to 150-200~
practically does not change the structure of hardened y-solid solution; however, in conse-
quence of reduced internal stresses [2], the damping ability of the alloy even decreases
slightly. When the temperature is raised to 400~ and the subsequent cooling is carried out
at the same rates, the level of energy losses of alloy No. 3 (Table i) approximately doubles
(curves 2 and 3 in Fig. 3), nevertheless the dissipative properties are insignificant (vibra-
tion decrement < 0.7%). In this connection it should be noted that the highest damping level
is attained with the lowest cooling rate (5~ The level of energy dissipation after
heat cycling at 600 and 850~ is practically the same as after heat cycling at 400~
If after all heat-cycling regimes of hardened alloys they are tempered at 400~ 4 h
with cooling in air, then the level of energy losses increases by approximately two orders
of magnitude (Fig. 4).
Thus the obtained results show that the nature of the effect of different heat-cycling
regimes on the damping ability of copper--manganese base alloys is different in dependence on
the initial state. Ways were shown of ensuring high damping ability of manganese--copper
alloys after various regimes of heat cycling, e.g., after welding; this is of great practi-
cal interest.
Heat cycling (e.g., welding or some other technological operation involving heating of
the material of a product or semiproduct to a temperature above 400~ of copper-~nanganese
alloys is expediently carried out in the hardened state. To ensure high damping ability of
the material of a structure made of copper-manganese base alloys, it must be tempered at
400~ for 4 h with cooling in air.
LITERATURE CITED
i. B.S. Chaikovskii, G. Ya. Yaroslavskii, L. A. Bocharova, et al., "The effect of some
chemical elementsand heat treatment regimes on the damping ability of manganese-copper
alloys," Probl. Prochn., No. 12, 107-110 (1976).
2. Yu. K. Favstov, Yu. N. Shul'ga, and A. G. Rakhshtadt, Metal Science of Highly Damping
Alloys [in Russian], Metallurgiya, Moscow (1980).
3. V.T. Troshchenko, V. V. Matveev, B. A. Gryaznov, et al., The Load Capacity of Rotor
Blades Under Vibration Loads [in Russian], Naukova Dumka, Kiev (1981).
1124
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