Friction and wear in machinery

Friction and wear in machinery

Int. J. Mech. Sci. Pergamon Press Ltd. 1963. Vol. 5, pp. 187-188. Printed in Great Britain BOOK REVIEWS D. McLEAN: Mechanical Properties of Metals...

122KB Sizes 0 Downloads 82 Views

Int. J. Mech. Sci. Pergamon Press Ltd. 1963. Vol. 5, pp. 187-188. Printed in Great Britain

BOOK

REVIEWS

D. McLEAN: Mechanical Properties of Metals. J o h n W i l e y & Sons Inc., N e w Y o r k a n d L o n d o n , 1962. x v + 4 0 3 pp., 90s. AFTER r e a d i n g this b o o k it is difficult to believe t h a t t h e r e was a time, a n d n o t v e r y long ago a t t h a t , w h e n some m e t a l l u r g i s t s were sceptical of t h e n e e d to i n v o k e t h e e x i s t e n c e of d i s l o c a t i o n s in o r d e r to e x p l a i n t h e m e c h a n i c a l p r o p e r t i e s of m e t a l s . Dr. M c L e a n ' s s c h o l a r l y work u n d e r l i n e s in a forceful a n d e l e g a n t f a s h i o n h o w t h e t e c h n o l o g i c a l l y i m p o r t a n t m e c h a n i c a l p r o p e r t i e s of m e t a l s are d o m i n a t e d b y t h e t h r e e - d i m e n s i o n a l d i s l o c a t i o n n e t w o r k a n d t h e w a y in w h i c h it is modified b y a p p l i e d forces a n d t h e r m a l f l u c t u a t i o n s a n d is c o n s t r a i n e d b y solute a t o m s , p r e c i p i t a t e s a n d c r y s t a l b o u n d a r i e s . A d e t a i l e d k n o w l e d g e of d i s l o c a t i o n s t r u c t u r e is n o w seen t o b e as v i t a l t o t h e m e t a l l u r g i s t w h o wishes to u n d e r s t a n d m e c h a n i c a l b e h a v i o u r as is t h e o p t i c a l l y o b s e r v e d m i c r o s t r u c t u r e to t h e m e t a l l o g r a p h e r s t u d y i n g alloy e q u i l i b r i u m . I m p o r t a n t progress h a s b e e n m a d e since 1953 w h e n C o t t r e l l ' s classic Dislocations and Plastic F l o w i n Crystals laid o u t t h e firm f o u n d a t i o n s of d i s l o c a t i o n t h e o r y ; t h e s e d e v e l o p m e n t s s t e m f r o m t h e a b i l i t y to m a k e d i r e c t o b s e r v a t i o n s of d i s l o c a t i o n a r r a n g e ments by high resolution transmission electron microscopy, albeit with the restriction t h a t is i n e v i t a b l e i n t h e n e e d t o e x a m i n e v e r y t h i n specimens. M c L e a n gives a clear p i c t u r e o f t h e real c o n t r i b u t i o n t h a t t h e s e studies are m a k i n g in e l i m i n a t i n g m u c h of t h e s p e c u l a t i o n f r o m t h e i n t e r p r e t a t i o n of m e c h a n i c a l b e h a v i o u r in t e r m s of dislocations a n d , at the same time, he demonstrates the uncanny accuracy with which dislocation theory was d e v e l o p e d to a useful s t a t e before a n y d i r e c t o b s e r v a t i o n of dislocations was possible. T h e b o o k gives a clear a n d s a t i s f y i n g a c c o u n t o f t h i s r a p i d l y d e v e l o p i n g s u b j e c t , b e g i n n i n g w i t h elasticity of m e t a l s a n d alloys a n d t h e n r e v i e w i n g t h e l a t t i c e defects t h a t influence m e c h a n i c a l p r o p e r t i e s , n a m e l y dislocations, p o i n t defects a n d c r y s t a l b o u n d a r i e s . T h e n follow c h a p t e r s o n a n e l a s t i c i t y , plastic yield in m e t a l s of good p u r i t y , s t r a i n h a r d e n i n g in p u r e m e t a l s , alloy h a r d e n i n g a n d fracture. R e c o v e r y a n d r e c r y s t a l l i z a t i o n are discussed as a n e c e s s a r y p r e l u d e to t h e c h a p t e r o n creep, t h e n follow c h a p t e r s on f a t i g u e a n d r a d i a t i o n d a m a g e a n d a b r i e f n o t e o n stress corrosion u n d e r l i n i n g t h e i m p o r t a n c e of surface e n e r g y here a n d so e s t a b l i s h i n g k i n s h i p w i t h b r i t t l e fracture. One is i m p r e s s e d t h r o u g h o u t b y t h e a u t h o r ' s s c h o l a r l y i n t e g r i t y ; h e leaves n o d o u b t t h a t h e h a s a c r y s t a l - c l e a r u n d e r s t a n d i n g of e v e r y s t a t e m e n t h e writes a n d it is e v i d e n t t h a t m u c h careful a n d original t h o u g h t h a s gone i n t o t h e p r e p a r a t i o n of t h e book. T h e closely a r g u e d a n d well cross-referenced t r e a t m e n t m a k e s it a t e x t for t h e serious s t u d e n t , p a r t i c u l a r l y m e t a l l u r g i s t s a n d a s p i r i n g m e t a l physicists. Careful p e r u s a l of its pages will reveal t h a t t h e a n a l y s i s of m e c h a n i c a l b e h a v i o u r of m e t a l s is r a p i d l y b e c o m i n g all-of-apiece a n d t h a t t h e fields t h a t G. I. T a y l o r a n d his c o n t e m p o r a r i e s b e g a n to c u l t i v a t e in t h e m i d d l e t w e n t i e s are a s t o n i s h i n g l y fertile. K. M. ENTWISTLE

Friction and Wear in Machinery. Vol. 13. P e r g a m o n Press, L o n d o n , 1959. 263 pp., 70s. THIS p a p e r b a c k e d i t i o n is a s p o n s o r e d t r a n s l a t i o n f r o m t h e R u s s i a n b y t h e R e s e a r c h C o m m i t t e e o n L u b r i c a t i o n of t h e A.S.M.E. u n d e r t h e c h a i r m a n s h i p of Professor M. D. H e r s e y . T h e b o o k c o n t a i n s n i n e p a p e r s a n d includes t h e d i s s e r t a t i o n s of a s p i r a n t s to t h e I n s t i t u t e for t h e Science of M a c h i n e s (USSR). T h e b o o k is r e c o m m e n d e d for b o t h t h e specialist a n d t h e p r a c t i s i n g e n g i n e e r w h o is a c t i v e l y c o n c e r n e d w i t h l u b r i c a t i o n , friction a n d wear. T h e p r o b l e m of t h e s t r u c t u r e of c a r b o n steels o n w e a r r e s i s t a n c e w i t h fixed a b r a s i v e s is c o n s i d e r e d b y S o r o k o - N o v i t s k a i a in t h e first p a p e r in w h i c h t h e m i c r o s t r u c t u r e a n d h e a t t r e a t m e n t of v a r i o u s steels a r e i l l u s t r a t e d . T h e conclusions are crisp a n d clear a n d e s t a b lish t h a t steel w i t h a m a r t e n s i t i c s t r u c t u r e is m o s t r e s i s t a n t to wear. 187

188

Book Reviews

A f u r t h e r p a p e r b y V a l ' d m a o n a b r a s i v e w e a r is c o n c e r n e d w i t h b o t h t h e m e c h a n i s m of w e a r a n d t h e d e p e n d e n c e of friction a n d w e a r o n v a r i o u s factors s u c h as t h e d i m e n s i o n s of t h e a b r a s i v e particles. W e a r o n t h e p h m g e r s a n d c y l i n d e r s of diesel fuel p u m p s is i n v e s t i g a t e d b y G. A. T a s h k i n o v . T h e conclusion is t h a t w e a r is d u e t o t h e p r e s e n c e of a b r a s i v e s in t h e fuel a n d t h a t wear r e s i s t a n c e is a t least d o u b l e d b y u s i n g c h r o m i u m - p l a t e d plungers. A n e x p e r i m e n t a l i n v e s t i g a t i o n b y E l i n verifies one cause of t h e m e c h a n i s m of w e a r in m e t a l s d u e to t h e m u t u a l p e n e t r a t i o n of p a r t s of t h e surface layers of c o n t a c t areas u n d e r load. P a r t i c u l a r p r o b l e m s of c h e m i c a l e n g i n e e r i n g i n v o l v i n g l u b r i c a t i o n of b e a r i n g surfaces b y s u l p h u r i c acid are c o n s i d e r e d b y Lialin. T h e t h e o r e t i c a l p a p e r b y M a r o c h k i n is d i r e c t e d t o w a r d s t h e p r o b l e m of t h e s t a t e of' stress a t t h e c o n t a c t of r o u g h surfaces a n d links t h e s o l u t i o n for a single conical p r o t u b e r a n c e w i t h t h e slip line s o l u t i o n for a wedge. T h r e e p a p e r s on film l u b r i c a t i o n c o m p l e t e t h e list of t e c h n i c a l papers. T h e m a t h e m a t i c a l s t u d y a n d e x p e r i m e n t a l results of a 120 ° film j o u r n a l b e a r i n g u n d e r s t e a d y a n d a l t e r n a t i n g loads are g i v e n b y Z o m m e r . I t is t h e o p i n i o n of t h i s r e v i e w e r t h a t t h e a n a l y t i c a l a p p r o x i m a t i o n t e c h n i q u e s in t h e p a p e r could well b e r e p l a c e d b y digital c o m p u t e r solutions. K h r i s h a n o v a describes t h e use a n d f o r m of a s e m i - c o n d u c t o r t r a n s d u c e r u s i n g m a n g a n i n as a n inertia-less a n d sufficiently a c c u r a t e p r e s s u r e t r a n s d u c e r for oil b e a r i n g work. T h e s a m e a u t h o r p r e s e n t s , in t h e final p a p e r , a n a n a l y t i c a l a n d e x p e r i m e n t a l i n v e s t i g a t i o n of t h e p r e s s u r e d i s t r i b u t i o n in a bearing, w i t h t h e axes of j o u r n a l a n d b u s h i n g skewed. A 49-page b i b l i o g r a p h y of W e s t e r n a n d Soviet p u b l i c a t i o n s for 1955 a n d 1956 c o m p l e t e s t h e book. J. K. ROYLE