Issue 14

D.

Firrao et alii, Fr

attura ed Integri

tà Strutturale, 1

4 (2010) 81-92

; DOI: 10.3221/I

GF-ESIS.14.09

M Al Cu Br Br Au Ag N Au Au Au

ETALS AND

ALLOYS

 sf

v

alues (mJ/m 2 166

)

80 35 15 42 21 128

ass (10% Zn ass (30% Zn ) )

i stenitic stain stenitic stain stenitic stain Stacking-fault

less steels AI less steels AI less steels M energy (  sf ) va epends on t ng the path s h as those u oys, as well a e possibility straight lines s about twice s, but an inc rds parallel t sions lower t alid also for ecause brass

SI 304-316 SI 310 n-Cr lues of some m he temperatu et for by  c,tw sually encoun s stainless st of bomb exp having k s an as k s . The v rease of the o itself, inter han 50  m) u brasses; her -  ftw is quite

21 40 11 ys at room tem rmation rate epend on th c by analyzed, cause of an ular coefficie not much in rate, from 10 raight line fo , whereas co per, in the c Cu-  ftw . losions,  y

Table 1 :

etals and allo

perature.

or slip,  fs

similar to  n rate and m if this on of their kind . ly. As it reg the deforma makes the H ig. 10). In th pper deform sion, twinnin y,tw

Th wh red Th not Cas be Th Cu rate Pet con twi alw

e Peierls-Nab ereas the ana uces with the erefore, at hi too high. es referring usually encou e Eqs. 1 and , Meyers et al for low val ch straight li ditions fine g nning. Analo ays favoured

arro stress f logous stress temperature gh deformati to Cu, Al, Au ntered when 2 can be rep . [13] sugges ues of applie ne for slip to rain copper gous conside at all grains

, d

re and defo in , does not d tered in exp eels, are here losions as the d k tw as ang alues of k s is deformation secting the st ndergoes slip e, unlike cop smaller than

in a manner e deformatio an go over  since metals aircraft crash nt, respective fluenced by -3 to 10 6 s -1 , r twinning (F arse grain co ase of explo

c,slip , ildly e is can ards tion all ese s by g is

,  ftw

, followi

. on rates, suc and their all exploring th resented by ted that k tw i d elongation move upwa (grain dimen rations are v dimensions b

500

Tw Hy 10 Sl 10 Sl 10 Sl

inning pothetical E6 (1/s) ip E3 (1/s) ip E-3 (1/s) ip

400

300

200

100

Flow stress [MPa]

0

0,05

0,1 0,15

0,2 0,25 d -1/2 [µm -1

0,3 0,35

0,4

/2 ]

Fig

ure 10 : Hall-P

etch plots for

plastic flow sl as sugges is about twi grains dimen hock loaded exhibit twinn For the tran become lo  martensit ely Ni, Ni an

ip (10 -3 , 10 3 an ted by Meyers ce as k s at 1 sions exceed [14]: in the c ing, accomp sformation  wer than  ft e was observ d Cr, and Ni

d 10 6 s -1 ) and et al. [13]. and 5% de 55  m. Sam old rolled sa anied by th   a   te w when crys ed during t , Cr and Mo)

twinning (Hyp

othetical) for

Cu,

Als app 23 wh par gra coe qua

o for stainle roaching the to 187  m w ereas the sh ticularly evid in dimension xistence of ternary Co a

ss steels (AI yield point, ere either co ock loaded o ent in the sm s decrease. mechanical t lloys (contain

SI 304) k tw especially if ld rolled or s nes mainly aller grains. Thus   can winning and ing respectiv

formations ples with gra mples slip is e formation nsion is nece tals are belo ension tests and on Mn

levels and it ins dimensio the only way of platelets ssary, whose w a certain on FCC bin Cr-C stainles

increases, w ns varying f of deformat of  marten value lower dimension. ary, ternary s steels [15].

hile rom ion, site, s as The and

86