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1 i i, > / T' - 'v ^ -»' bl - V O LA A* a 6^ T t- V ex : LtoCSo

2 n -* >«?* ^ i O vi^ IT y- s>v^ c ^» f P N a < 0P: p b' 0 I -^" /* soh SJ - J * ^ - K^*» ^ *J T- pj f«e?lfc >?

3 - f* >* V *- - '~~ - - -, " ' -, * p * - ' -,» *,a f f -: "S :

4 l ' LU»v f ^- * *» i j^i j M-kiJc"- b3 Unslipped Slipped Slip plane Figue 418 (a) (I 10) slip in FCC cystals The unit slip vecto of the complete dislocation,!>,, is a/2 {I 10]; two patial slip vectos, the sum of which poduces the same net motion as bi ac b- and!>; (/') Faulted egion of width iv between the two patial dislocations bj and b,, fw L ik " - - V - - it U-Utt '* - - k CC 'U ') t\ t :

5 (1/6) (112) (1/6) [I II] d/6) [Hi] (211) d/6) [111] Fig 1116 Dissociated scew dislocation in the bcc lattice The foms (a), (b), (c) have diffeent symmeties and theefoe need diffeent foces to move them, eg to the ight in the hoizontal (112) plane Fig 1117 Coss-slip by a dissociated scew dislocation in the fee lattice afte [115] In stage (a) a constiction of length / foms in (111), in (b) and (c) extends on (111) Undissociated dislocation 0/2(101) Cottell-Lome sessile Dissociated dislocations Leading: o/6 l]21 Tailing: a/6[2ll) (a) Dissociated dislocations Leading: a/6[u2 Tailing: a/6[121 Tailing patials Undissociated dislocation a/21011] Coltell-Lome dislocation Pi led-up dislocations (c) Figue 419 Fomation of a sessile dislocation, (a) Tlic motion of dissociated dislocations on two intesecting slip planes, (Ml) and (I IT); (6) the elative oientation of the (wo intesecting planes in (a), and (c) the combination of leading patial dislocations moving on the two intesecting planes to poduce a sessile dislocation whose Buges vecto lies in neithe plane see (b) ^-tte f l\

6 tto d o \fji- (f) ^t^^-^---'-"5-"* Figue 421 The Fank-Rend dislocation souce (,-/} A cystal con In in ing an edge dislocation wild a I;,1IT-plane jog: (b) liic iinc cp,csc;;[::^ [lie (Jislocntio coe Tiic dislocation is pinned it poils // ad C Tiic subsequent pats of liic i!lus[;i;io:i show the sequence of events ;is ihc dislocniioii line bulges ihough between llic pinnig pofnis, swjn»s aound them, anj meets o the fa side to ni;ikc 1 complete dislocation loop and cfoin ihc iilial ling,scs:!;ieiit /*C Fig (a) Cuved dislocation line; (b) dislocation_segmcnt DD' becomes unstable unde the foce h and joins with D'D" leaving a loop ound D'\) Fank-Read souce of length / = DD' poduces a dislocation loop and epoduces itself

7 c ) -v - -X * > vj ij t -- «^ -- fc- --TT- ^\^ ^N Ll '* ^/? T* iv C c 5 - Vi^ <;; n T -

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9 '""""T n v "^'"v _ ^ "y **M S ifsfft ' ' 7 "V - ^» '-* ->^ V 1 i 1 ' s I g"" " * vy"^ ^-^v\vv?^/^ X I* 3 *" ^i ^,

10 ? m - f iv,*, v ~ ^ 5: 3* ** * V H--? J? ft-tp

11 ?fa

12 i-v gain II - gain 1 b_ 9 \- tilt V I 0 u A SK u v d X I _ " A &^t 1 Fig 34 Asymmetical tilt bounday made up of two sots of edge dislocations with mutually pependicula Buges vectos

13 f S 2MI /- e VJA ; _ Tf^Cf t a»oadf1^gtt«q «**»» vvlu * U e?voi g *^g&?*s2^?itesssifci? ' & SS 00««o ''PP0UJ aas^ksssss^feasa^ «««'?^- '0't>ooo0oc,45wa^c» * * fl ^ *? P^-OKJ^^SS^&O^^ ** <"> Fig, 35 Two lattice planes otated with espect to one anothe (open and full cicles) (a) and the esulting quadatic netwok of scew dislocations (sepaation /i) (/>) M <- P U_ en C o O ^Ov ^o^ wjc - *2- * ^* 3L -> il_^>ul ^--i^* '-^^^^,y *~<i^f-* ^ l_«- ^ud JL - cdbowt

14 ;/j *i 1! (T> J«K~* < % fv- * V ^?"=*,v- \' \; v ' v- }0-\\v \,-o V- V ' V " o- \' \' \' \' ' -o,,-o^ >,-H ',- x S0- i ;0- \' \j An V A,_ ^ / v A,, -X t * j^* "' '^ ^w ^ c- ^=* '--' i_ 0 " : & -f \ 0 i * v-!; s ^o ' ; " "- \* JL ; ' '- - ^1 ^,

15 *^- > ^~ o "S J O^ I ('""' K" " - ^»^> ^ds C7- h -P *-' TT o p -u 0 \ 0 ^^ cx^, Vv- P i-,fo

16 VL "V - '- "- Fig 6 Schematic diagam of the aangement of the atoms in a 40 (110) lilt bounday in tungsten, deived fom a sequence of field ion micoscopy images The position of the (HO) common tilt axis in the two gains is indicated Numbes 1-5 indicate subsequent layes of the bounday Lettes A,-AS label one of the polyhedal ings poposed by POTM-OV el vl [1971], ;ig 7 Stuctue of a 369 (100) till bounday between fee cystals, in icnns of polyhedal units Tli bounday is composed of slacks of capped tigonal pisms

17 I Fig 4 Lattice-coincidence model of a 18 till-type gain bounday between two hexagonal aays of atoms Tlic atoms at coincidence sites ac indicated by coss-ha telling The "sufaces" of llic two cystals ac maked by dashed lines ooooooooooo ooooooooooo oo_ooooooooo ooooooooooo ooooooooooo ooooooooooo ooooooooooo ooooooooooo ooooooooooo o o o o o o o oo o o Fig 39 Coheent twin bounday (I,

18 - - ; - - H _ s o cili -%*' "v*^, "*:, ** ^ _! Vl «& «< >? ' - " - 6 -/ _ -, -

19 \b ^ *\j2/ves (LJu^^ \ J/,dW\^ 10 :o oieni;iiion diffeence i SO Fig 314 Dependence of the bounday enegy E on the a between the gains shown schematically fo coppe afte [' Limiting values ae given fo low-angle gain boundaies ( angle gain boundaies (Eh) and sufaces (Es) a and b she position of special low enegy boundaies and t of cohee boundaies

20 / ' {

21 FAZISHATAROK koheens koheens defomalt eszlegesen koheens (szemikoheens) inkoheens -Ai [ooj)j [oo<] f /x/x 0-2oo Koh eenca : OL n <dlc e\