Van den Beukel_1976_Inhomogeneous plastic deformation in a Au-Cu alloy

The specimens w ere i v e n a p r e s t r a i n e the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: w ere ~ i v e n a p r e s t r a i n E. The g r i p v e l o c i t y was ~ = 0,1 Cm/mi . The t e m p e r a t u r e was 0-C. Under these c o n d i t i o n s the d e f o r m a t i o n is homogeneou n up to E = 18% where t he PL e f f e c t s t a r t s . A f t e r p r e s t r a i n l n g the specimen was aged a t 0°C d u r i n g t • Upon f u r t h e r d e f o r m a t i o n a lLiders band was o f t e n o b s e r v e d . In f i g . 1 the lLiders a s t r a i n , Z~EL is g i v e n as a f u n c t i o n o f a g i n g time and p r e s t r a i n . Note t h a t f o r : 6% and 8% the d ata p o i n t s a t t = 0,5 min are a b s e n t . In these cases a l ~ d e r s b and c o u l d n o t be d e t e c t e d . This inadicated t h a t c e r t a i n minimum v a l u e s o f p r e s t r a i n a nd a g i n g time are r e q u i r e d f o r the o c c u r r e n c e o f d e t e c t a b l e l~ders bands. 2 . 2 . Repeated y i e l d i n g . In a number o f cases r e p r e s e n t e d in f i g . 1 the f i r s t IL~ders b'and was f o l l o w e d by subsequent ones. In a p r e v i o u s paper [ 1 ] an e x p e r i m e n t was d e s c r i b e d , r e l a t i n g the o c c u r r e n c e o f a second band to the p r o p a g a t i o n time t L o f the f i r s t band. The p r o p a g a t i o n time in a specimen o f l e n g t h ] is g i v e n by I~ L tL - * ~ (I) g o l d s o l v e n t w i t h 14% copper s o l u t e . 533 Inc 5 34 INHOMOGENEOUS DEFORMATION IN Au-Cu ALLOY Vol. I0, No.6 1 6% FIG. 1, LEders strain versus aging time for d i f f e r e n t values 14 o f the prestrain. & E:L(¶ t 12 t L can be varied by varying the grip velocity g upon contlnued straining after aging. At room temperature i t was found that a second band occurs i f 1 / t L < 1 0.2 1 . 4 7 2 Z, 6 . 8 t Q (rain) being the prestrain. I t may be concluded that a second band is observed i f the propagation time exceeds a c r i t i c a l value. 10 I f a second band is f o u n d , the band s t r a i n can be c a l c u l a t e d from the d a t a o f f i g . 1, which was d e t e r m i n e d f o r f i r s t I~ders bands. This can be done as f o l l...
View Full Document

This document was uploaded on 01/23/2014.

Ask a homework question - tutors are online