HAL Id: jpa-00220996
https://hal.archives-ouvertes.fr/jpa-00220996
Submitted on 1 Jan 1981
HAL is a multi-disciplinary open access
archive for the deposit and dissemination of
sci-entific research documents, whether they are
pub-lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d’enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.
INTERNAL FRICTION IN MOLYBDENUM
CONTAINING NITROGEN IN SOLID SOLUTION
FORM
G. Haneczock, T. Poloczek, J. Morón
To cite this version:
JOURNAL D E PHYSIQUE
Colloque C S , suppldment atr nO1O, l'ome 4 2 , octobre 1981 page C5-8 1 1
INTERNAL F R I C T I O N I N MOLYBDENUM C O N T A I N I N G N I T R O G E N IN S O L I D SOLUTION FORM
G. Haneczok, T. P o l o c z e k a n d J.W. Moroh
I ? z s t i t u t e o f Physics and Chemistry o f Metals, S i l e s i a n University, 40-007 Katowice, Bankowa 1 2 , Poland
Abstract.- Iqolybdenum samples n i t r i d e d a t 2400 I; f o r 10 min and quenched i n t h e l i q u i d Wood's a l o y have been s t u d i e d by t h e in- t e r n a l f r i c t i o n /IF/ method. Two r e l a x a t i o n d l peaks have been observed on t h e I F curves: A a t 392 K and B a t 498 K / f = 1 cps/. Parameters of t h e Arrheniu6 l a w f o r b o t h peaks have been determi- ned from t h e i r temperature a h i f t /f=I-10 cps/ and from numerical decompositions of $he e x p e r i n e n t a l curves i n t o elementary proce- sses. It has been proposed t h a t peak A i 8 one of t h o d i s l o c a t i o n -
alp
peaks i n bcc m e t a l s while B i e t h e n i t r o g e n Snoek r e l a x a t i o n i n 1.b.1. I n t r o d u c t i o n . l n t e r n a l f r i c t i o n i n molybdenum w i t h - n i t r o g e n c o n t e n t w a s s t u d i e d f o r i h e f i r s t time by Fiaxinger an5 Schwope
[I]
who conside- r e d t h e peak a t 580-
640 K o b t a i n e d f o r f = l cps t o be t h e n i t r o g e n Snoek r e l a x a t i o n . l.1 and Son[2] found this r e l a x a t i o n a t 433 K /f=lcpsL Verner e t a1 [3] have shown t h a t t h e presence of n i t r o g e n atoms i n samples s a t u r a t e d w i t h oxygen g i v e s r i s e t o t h e appearence, beside t h e oxygen Snoek r e l a x a t i o n /T -343P
K,
f = l cpa/,of a d d i t i o n a l peaks a t temperatures 323, 393 and 448 K /f=2 cps/. The a u t h o r s of 13') have assumed t h a t t h e peak a t 448 K i s t h e n i t r o g e n Si~oek r e l a x a t i o n and t h e peak a t 393 K i s r e l a t e d t o Yne d i r e c t i o n a l ordering of 0-N p a i r s ; however, t h e y have n o t given any model of formation of t h e peak a t 323K.I n i n v e s t i g a t i o n s on t h e s t r e s s r e l a x a t i o n in v e r y pure Mo [4]
,
n i t r i d e d and quenched i n mercury* one of t h r e e observed p r o c e s s e s has been i n t e r p r e t e d as t h e d i r e c t i o n a l o r d e r i n g of M atoms w i t h f o l l o w i n g parameters of t h e A r r h e n i u ~ l a w : Q=l.O eV, % = 2 . 5 ~ 1 0 - ~ ~ ~ . A n IF peak a t 395 K f o r 1 cps corresponds w i t h them.2. I n v e s t i ~ a t e d samples, experimental method, r e s u l t s of ncasuements. I n t h e p r e s e n t paper a molybdenum w i r e , 1 lllm in diameter, has been studied. It contained l e s s t h a n 0.03 p c t s u b ~ t i t u t i o n d l i m p u r i t i e s whi- l e c o n c e n t r a t i o n s of i n t e r s t i t i a l s were following: N
-
17 ppm, 0-
150 ypm, C-
20 ppm. The m a t e r i a l w a s i n i t i a l $ y cleaned by h e a t i n g in vacu- um / 2 x 1 0 - ~ ~ r / a t 2400 K f o r 1 hour, A f t e r such c l e a n i n i g t h e chemical a n a l y s i s of Mo r e v e a l e d 8 ppm N, 80 ppm 0 , 10 ppm C. N i t r i d i n g of sam- p l e s was c a r r i e d o u t by h e a t i n g them a t 2400 K in t h e n i t r o g e n atmos-C5-812 JOURNAL DE PHYSIQUE
phere f o r 10 minutes under t h e atmospheric measure. I n o r d e r t o g e t a s u p e r s a t u r a t e d s o l i d s o l u t i o n t h e s a n p l e s were quenched from t h e n i t r i - d i n g temperature i n t h e Wood's a l l o y k e p t a t approx. 400 K.
I F measurements were performed by means of an i n v e r t e d KG pendu- lum, d e s c r i b e d in [5]
,
i n t h e temperature range 300-
700 K i n vacuumTr/;
l i n e a r h e a t i n g w i t h a r a t e of 1 K per minutew a s
applied. The temperature wan measured by a thermocouple s i t u a t e d in t h e c l o s e v i c i n i t y of t h e middle of t h e sample. The amplitude of v i b r a t i o i l s w a s 2 x 1 0 - ~ and t h e frequency v a r i e d from 1 t o 10 cps. During measurements along t h e 12 o r l o n g sample t h e r e was a l i n e a r temperature g r a d i e n t v a r y i n g l i n e a r l y w i t h temperature. Regarding t h e middle of t h e sample t h e s e v a r i a t i o n s were d i s c r i b e d by equations: i n the range 300-
400 K-
(
0.0058xT-
1.7) K/cm and i n t h e range 400-
700 K (0.01 5xT-
5.5) K/cm. A f u r n a c e h e a t i n g the sample was s i t u a t e d s o t h a t -the rainhium a d maximum temperature occurred s p i n e t r i c a l l y a t ends of t h e sample.I n f i g . I i s p r e s e n t e d t h e I F curve o b t a i n e d f o r a i.10 sample clean- e d by t h e h e a t t r e a t m e n t and quenched i n t h e Wood's a l l o y /curve 1/. The I F peak observed a t 339 K /f=6.3 cps/ i s r e l a t e d t o a l a y e r of t h e Wood's a l l o y forming on t h e s u r f a c e of t h e sample and disappears com- p l e t e l y a f t e r cliemical e t c h i n g / f i g . 1
,
curve 2/. The temperature of t h e observed peak does n o t depend on t h e v i b r a t i o n frequency and corre- spoilds w i t h t h e m e l t i n g p o b t of t h e a l l o y b 3 4 0 K/. S i m i l a z e f f e c t s , r e l a t e d t o a s u r f a c e l a y e r of o i l o c c u r r i n g on i n v e s t i g a t e d samples, was r e f e r r e d in [6].
I n t h e course of f u r t h e r i n v e s t i g a t i o n s b e f o r e I F measurements samples were etched chemically i n o r d e r t o e l i m i n a t e t h e described e f f e c t s .I n f i g . 2 /curve I / i s p r e s e n t e d t h e IF curve obtained f o r a sample cleaned by t h e h e a t t r e a t m e n t /2400 K/lh in vacuum/ a i d quenched from t h i s temperature. On t h i s curve only a am31 r e s i d u a l peak can be seen a t 532 K
/f=5.9
cps/. This peak may be r e l a t e d t o r e s i d u a l i n t e r s t i t i a l i m p u r i t i e s which cannot be removed from t h e s w p l e by t h e a p p l i e d me- thod. In t h e s a c f i g u r e i n p r e s e n t e d t h e I F curve obtained f o r a s a - p l e cleaned by t h e h e a t t r e a t m e n t and subsequently n i t r i d e d a t 2400 K f o r 10 min and quenched /curve 2 / ; t h e nitrogeil concentrat;ion was 111 ppm. It can be seen t h a t i n consequence of t h e e x i s t e n c e of n i t r o - gen i n o o l i d a o l u t i o n two I F peaks appear: A a t 425 K and B a t 531 K /ft5.5 cps/. A s a r e s u l t of h e a t i n g during I F measurements /approxima- t e l y up t o 700 K/ peak A d i s a p p e a r s completely wheras peak B i s redu- ced by 90 pct.t h e following values have been obtained: f o r A
-
~ = ( 0 . 8 3 ~ 0 . 0 7 ) eV and IU-Oo7
)
x ~ ~ - 1 4 B.'(3
x o 2 , f o r B-
~ = ( 1 . 3 0 ~ 0 . 0 6 ) eV and l o = ( l . l+,.S u i t a b l e diagrams are preeented I n f i g s .
3
and 4. I t is Proper t o addF i 1 : 1
-
I F curve f o r a sample Fi 2 :IF curves f o r : 1-
a sample &ed born 2600 K in t h e Wood's & & e d and quenched /from 2400K/
a l l o y ; 2
-
I F curve f o r t h e same i n t h e Wood's a l l o y /f=5.9 cpe/; sample a f t e r chemical e t c h i n g of 2-
a a m p l e cleaned, n i t r i d e d a t t h e s u r f a c e l a y e r ; f r 6 . 3 cps. 2400 K f o r 10 min and quenched i nt h e Wood's a l l o y ; cN=lllppm /f=5.5 opa/.
: P l o t of t h e Arrhenine law : P l o t of t h e Arrheniue l a w o r proaeas A.
C5-8 14 JOURNAL DE PHYSIQUE
t h a t f o r (WTL-0.07 [7'] the pre-exponential f a c t o r f o r r e l a x a t i o n A is
4x1
0-I 'a.3. Numariaal analysis of I F curves and diaoussion o f r e s u l t s ,
The determined I F curves were decomposed i n t o two elementary pro- cesses
/
A and B/ using the method of f i t t i n g t h e physical parameters t o experimental points by means of minimization of mean square devia- tions.I n the case of existenae of a l i n e a r temperature gradient along the sample the Q"(T) curve i s described by the i n t e g r a l [ 8 ] :
-
'42where
L
i s the lenght of the-eample, k-
the temperature gradient, x-
the coordinate along the sample; A , Q and T P denote the i n t e n s i t y , t h e a c t i v a t i o n energy and the peak temperature of the r e l a x a t i o n a l process / f i t t e d parameters/, respectively.It can be shown t h a t i f the i n t e g r a t i o n limits i n (1) are symmetri- c a l /a symmetrical temperature gradient/, the maximum of curve ( 1) occu- rrs a t T with good accuracy. Taking i n t o account v a r i a t i o n of k wit'n
P
temperature /aa given above/ does not d i s t u r b this condition.
I n fig.5 i s presented a s an instance a comparison of the theoreti- c a l curve oalculated acaording (1) with experimental points /curve 2 of fig.2/. A c e r t a i n m i s f i t v i s i b l e i n the high- temperature s i d e may be r e l a t e d t o deformation of the curve due t o the p r e c i p i t a t i o n of nitro-
gen from s o l i d solution. I n this way nine curves have been decomposed and the obtained mean values f o r Q and
TO
a r e a s followa: f o r A-
P-(0.82~0.09)eV.%
= (1.5::. 4)x10- l 1 s and f o r B-
Q= (1.2520.04) e ~ ,(5.
.(5_*~)x1~-1* s. Maximum deviations from nean values a r e taken a s values of errors. I t can be seen t h a t parameters of the Arrhenius l a w f o r both processes agree i n limits of e r r o r s with parameters obtained from temperature s h i f t of peaks with frequency.I n fig.6 a r e presented i n t e n s i t i e s A A ~ d Agof both r e l a x a t i o n s versus concentration of nitrogen. The i n t e n s i t y of process B increases l i n e a r l y with nitrogen concentration according t o the equation:
This f a c t and the order of magnitude of the pre-exponential f a c t o r
T,
/ I O ' ~ ~ B / seem t o point out t h a t process 3 i s the nitrogen Snoek r e l a x a t i o n i n Mo /TP=498 8, f = l cps/.r
Comparison of experimen- F i 6 : I n t e n s i t i e s of r e l a x a t i o n p o i n t s with t h e t h e o r e t i c a l &A ( 0 ) and r e l a x a t i o n B -A,(.) curve c a l c u l a t e d according (1) ; v e r s u s concentration of n i t r o g e n-
-
-
component proceesea.Arrowsdenote p o s i t i o n s of t h e Snoek C ~ . r e l a x a t i o n r e f e r r e d by v a r i o u s
authors.
fa5.5
cpe.wNch can o r i g i n a t e i n t h i s sample during quenching i n t h e l i q u i d metal. The f a c t t h a t f o r non-nitrided and quenched samples /fig.2,0urve 1
/
t h i s peak doee n o t occur p o i n t s o u t t h a t t h i s process ehould be a l s o r e l a t e d w i t h n i t r o g e n atoms i n t h e S o l i d s o l u t i o n ; s o , i t i s probably one of d i a l o c a t i o n a l /3 peaks observed i n bcc metals 19-1
I]
.
A s $or peak B r e s u l t s of t h e p r e s e n t paper a r e i n c o n s i s t e n t w i t h f i n d i n g s of [3] /!PP=438 K , I cps/ which oonfirmed t h e r e s u l t obtained i n [2] /Tp=433 K, f = l cps/. However, it i s worth t o mention t h a t t h e n i t r o g e n Snoek r e l a x a t i o n haa been obtained i n [3] w i t h t h e assumption t h a t one of I F peaks revealed f o r samples containing n i t r o g e n and oxy-
gen atoms i n t h e s o l i d s o l u t i o n corresponds w i t h t h i s r e l a x a t i o n . Nei- t h e r in [2) nor i n [3) a l i n e a r c o r r e l a t i o n between t h e n i t r o g e n con- c e n t r a t i o n i n t h e sample a n d t h e IF peak h e i g h t has been obtained.
A l i n e a r c o r r e l a t i o n may a l s o occur f o r t h e Snoek-KUster peak [12], Yet
it
seema p o s s i b l e t h a t peak B i s n o t due t o this r e l a x a t i o n because1. f o r t h e S-X peak
T
should increaae w i t h t h e concentration of n i t r o - PC5-8 16 JOURNAL DE PHYSIQUE
Ref
erencesl;R.E.YIinger, A.D.Schwope, The Anelmticity of Molybdenum, Battelle ~ ~ m o r i a l Institute 16-th Quarterly Report to OBR, July 1953
2,Y,L;Ma, I,Y.Son, Acta Metall. Sinioa 2,68 /1964/
3.V.
D.Verner, Yu.V. Piguzov, I. Y.Rehevskaya, Relaxational spectrum of molybdenum related to interstitials, in: Internal Friction in Yieta- llic Materials, Science Yub1.-Nauka,Moscow 1970, p. 61 /in ~ussian/4
.
J.H.Evana, B.L.Eyre, H.K.Birnbaum, Acta htall. _?8,835/1970/5. J.
Pietrzyk, J.Rrawuski, Pomiary, Automat~ka, Kontrola, N09,325/1976/ /in Polish/G.W.Chomka, M.Pstrokonski, E.Denga, Proceedings of
the
111 Polish Conference on Anelastic Relaxation and Magnetio After-Effects in Solids R.ENIOM-80, eds. J. W.Moroxi and J. Ilcr;uk, Silesian University, Katowice 1981, p. 91 /in polish/7;R.E.FAner, R.Gibala, P.A.Hultgren, Acta Metall. 1q,223/1976/ 8.D.E.Barrow, Z.C.Szkopiak, J.Phya.D, 2,1140/1970/
g.B;Escaig, Scr.Metal1. 5,199/1971/
10.
