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Submitted on 1 Jan 1981
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THE INFLUENCE OF THIN SURFACE LAYERS OF
MINERAL OILS ON THE DAMPING CAPACITY OF
METAL SAMPLES
W. Chomka, E. Denga
To cite this version:
CoZZoque suppZ6rnent au nOIO, Tome 4 2 , oetobre 1981 page C5-1165
THE INFLUENCE OF T H I N SURFACE LAYERS OF M I N E R A L O I L S ON THE DAMPING C A P A C I T Y OF METAL SAMPLES
W. Chomka and E . Denga
I n s t i t u t e of Physics, TeehnicaZ University o f ~ d a g s k , 80-952 a a h s k , PoZand.
a b s t r a c t . - Low t e m p e r a t u r e p e a k on t h e i n t e r n a l f r i c t i o n cl.?rvc f o r Copt s a m p l e s c o v e r e d i v i t h t h e l a y e r o f t n i n e r a l p a r a f f i n o i l s a s s f o u n d t o h e c o n n e c t e d n i t h t h e n a t u r e o f s u r f a c e l a y e r . The t e m p e r a t u r e p o s i t i o n o f t h e p e a k i s r e l a t e d t o t h o a e l t i n g p o i n t o f t h e s o l i d i f i e d o i l and i t s h e i g h t d e p e n d s on t h e anne- a l i n g t e m p e r a t u r e , 1, I n t r o d u c t i o n , - I n t e r n a l f r i c t i o n p e a k s a r e m a i n l y c o n c c c t e d 7.7iti1 b u l k e f f e c t s b u t i t i s a l s o Lnoqxn t h a t a r t e f a c t p e a k s a p p e a r when t h e a t m o s p h e r e s u r r o u t ~ d i n g t h e s a a p l e i s n o t p e r r c c t l y c o n t r o l J . c d o r i t s s u r f a c e i s n o t s u f f i c i e n t l y c l e a n e d , I n t h e s a m p l e s o f d i f f e r e n t r n e t a l s a n d a l l o y s c o v e r e d v i t h a t h i n l a y e r o f m i n e r a l o i l t h e cotap- l e x s p e c t r u n i o f i n t e r n a l f r i c t i o n a t t h e t e m p e r a t u r e r a n g e 1 6 0 t o 300 K was f i r s t o b s e r v e d i n works [1,2]
.
F o r b e t t e r u n d e r s t a n d i n g o f t h i s p:3enotlenon t h e p r e s e n t p a p e r d e s c r i b e s t h e e f f e c t of t h i n l a y e r o f d i f f e r e n t 2 a r a f P i n o i l s o n t h e i n t e r n a l f r i c t i o n o f Copt a l l o y s a m p l e s .2, 2xperiment.- The t e m p e r a t u r e d e p e n d e n c e o f i n t e r n a l f r i c t i o n and d e c a y o f o b s e r v e d s p e c t r u m w i t h i n c r e a s i n g a n n e a l i n g t e m p e r a t u r e \?as m e a s u r e d f o r e q u i a t o r n i c Copt a l l o y s a m p l e c o v e r e d w i t h d i f f e r e n t pa- r a f f i n o i l s a n d h y d r o c a r b o n C16N34. The Copt a l l o y was i n o r d e r e d s t a t e w i t h a lorn b a c k g r o u n d o f i n t e r n a l f r i c t i o n , The s a m p l e s had a f o r m o f w i r e a b o u t 60 mm i n l e n g h t and 1 1x11 d i a m e t e r , kIeasurer;ents w e r e perforrned w i t h a t o r s i o n pendulum o s c i l l a t i n g a t 0.5 t o 2.0 IIz, The h e a t i n g r a t e o f t h e s a m p l e s mas a b o u t 2 t o 3 IC/~oin.
The o i l l a y e r was p u t on by l u b r i c a t i n g b u t s i m i l a r i n t e r n a l f r i c t i o n s p e c r t a w e r e o b t a i n e d w i t h s a m p l e s quenched i n t o t h e o i l o r j u s t immersed, A p p r o x i m a t e c a l c u l a t i o n s o f l a y e r t h i c k n e s s s a s p o s s i - b l e by d e t e r m i n i n g t h e s a m p l e w e i g h t b e f o r e a n d a f t e r c o a t i n g . The l a y e r s t h i c k n e s s e s mere e s t i m a t e d a s 2 t o 6
pm,
3 , R e s u l t s a n d d i s c u s s i o n . - A f t e r c o v e r i n g t h e s a m p l e w i t h a t h i n l a y e r o f m i n e r a l o i l o r h y d r o c a r b o n a n a s y m e t r i c p e a k w i t h a n a s s o - c i a t e d modulus d e f e c t a p p e a r s , P i g . 1 shows t h e r e s u l t s o f i n t e r n a l f r i o t i o n m e a s u r e m e n t s , Q'~/T/, f o r f o u r Copt s a l n p l e s c o v e r e d n i t hC5-1166 JOURNAL DE PHYSIQUE
p a r a f f i r i o i l s f o r vacuc:? d i f f u s i o n pump /1/,/3/, vzcuum r o t a r y punp /2/ atla w i t h h y d r o c a r b o n ZZ61134 / 6 / a s mel?. a s f o r S o r t s a ~ ~ p l e with- o l ~ t eqy o i l l a y e r . Pig.1 a l s o s h o v s t h e t y p i c a l f r e q u e n c y c h a n g e s 2 f /T/ / f 2 i s p r o p o r t i o n a l t o s h e a r n o d u l u s G/ d c t e r ~ . l i n e d f o r sample ~ i t h C16:134.
ws
T k c t e i n p e r a t u r e dependence o f i n t e r n a l f r i c t i o n f o r s a m p l e s c o v e r e d w i t h a t h i n l a y e r o f : 1 , 3-
o i l s f o r vacuwa d i f f u s i o n pumps, 2-
o i l f o r r o t a r y pump, 4-
hydro- c a r b o n CT6113*, 5-
background. Upper s i d e : t e n p e r a t u r e depen- d e n c e o f v i b r a t i o n f r e q u e n c y f o r Copt sample c o v e r e d w i t h C16H34.280 I< r e s p e c t i v e l y , depending upon t h e Irind ol" a p p l i e d o i l . The p~eali h e i g h t a l s o c h a n g e s a i t h t h e lcind o f o i l .
7ig.2 shows t h e c!iaoges o f o peak i l e i g l ~ % /Q&/ a s a I ~ ~ n c t i o o aZ a n n e a l i n g te1n;;eroture /T,/.
l"ifr.2: I'cek h e i g h t a s e f i i i l o t i o n o f a n i ? e a l i n g t c ~ p e r a t u r e f o r CoI't c e n p l e c o v e r e d w i " u C
ir,Ii34
. ; c ~ i e a l i i l g t i : w a:, aacll Leriperrrture z a s a b o u t 2@ s i n . and a f t e r c o o l - i n g t h e s a i ~ p l e t o ahou-5 150 1: t h e i n t e r n a l f r i c t i o ~ ~ s a s ~ : i e a s u r e d , The r ~ o s t i n t e n s i v e c h a n g e s o i ;eaL k e i g ! ~ i s t a r t a t a h o u t 3 R C .:5 Peak a i l i ~ - . a l s o u t a f t e r h e a t i n g a t t h e t e n p e r a t u r e T
-
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e p p e a r i o be r e s p e c t i v e l y t h e n e l t i n g Le~1peratux-e a n d d e c o u ~ p o s i t i o a ternpera-ture c f t e s t e d o i l a t t h e lowered p r e s s u r e .Thr~a Ll1.e n a t u r e o f t h e i n t e r n a l f r i c t i o n peak s h o u l d b e a t t r i b u -
t e d t o Chc s u r f a c e l a y e r p r o p e r t i e s a n d n o t on1.y t o t h e b a s e p r o p e r -
, c 3 . a ~ .
-
JIoaever t h e o b s e r v e d i n t e r n a l f r i c t i o n s p e c t r u i a n d c h a u g e s o fC5-1168 JOURNAL DE PHYSIQUE
one c a n s e p a r o t e t h e s e two p r o c e s s e s i n t h e way s i m i l a r t o t h a t pro- posed i n (31 f o r 1:ietal
-
g l a s s composite.4
,
Conclusions.- I/ Lon t e m p e r a t u r e i n t e r n a l f r i c t i o n s p e c t r u m f o r t h e samples c o v e r e d w i t h t h e l a y e r of o i l f o r v a c u m punps shows t h e d i s t i n c t p e a k s a t t h e m e l t i n g t e m p e r a t u r e o f s o l i d i f i e d o i l . 2/ The g r e a t d e a l must be t a k e n f o r c l e a n i n g t h e s p e c i n e n s t u d i e d w i t h i n t e r n a l f r i c t i o n e s p e c i a l l y i n e x p e r i m e n t s i n v o l v i n g i r r a d i a t i o n o r quenching. 3/ The new method i s opened f o r s t u d y i n g t h e m e c h a n i c a l p r o p e r t i e s of d i f f e r e n t k i n d o f s o l i d i f i e d l a y e r of o i l s and t h e i r m i x t u r e s,
R e f e r e n c e s
1, \Y,Chomlia, hl.~strolroxiski and Z.Denga, P r o c e e d i n g s of RENIOA4