Microsoft Word - numero 14 articolo 9 T Do Pol Ita AB Air inv and Va me pre me situ Ca rep po Re fol KE Mi IN Th airc Th flig Th and A M Ma Th A P rev O he way onato Firra litecnico di Tor lia; donato.firr BSTRACT. En rport on Oc vestigation, r d lattice defo arious macro etals expose essure wave etal, the pre uations regar alculations to ported. Resu ssibly induc evisited theo llowing an o EYWORDS. S icrostructura NTRODUCTIO he fact n Oct oil co a field craft were fou he pilot, Irneri ght hours. he wreckage w d later destroy Morane Sauln attei was seate he forensic inves Pavia Court r velations by a O the mis ao, Grazia rino, Dipartim rrao@polito.it nrico Mattei ctober 27, 19 reopened mo ormations u o- and micro d to it. At t caused by a essure and t rding stainle o evaluate w ults of field ed on metal ories were ap n board sma Slip deforma al changes. ON tober 27, 196 nglomerate, E d in the small und dispersed io Bertuzzi, s was collected yed by re-mel nier 760 B, 4 ed on the fron stigation revisiting of t Mafia repent stery of ano Uberta mento di Scien i, the Preside 962 when hi ore than 30 under high ve o-structural c the microstr an explosion the strain ra ess steels, alu which defor explosion e targets by a pplied to the all charge ex ation; Mecha 2 the airplane ENI, crashed l village of Ba d by a line of since long tim without prec lting, after a P passengers je nt right seat ( the case occu tant in a Paler D. Firrao et the Ma alli, Paolo M za dei Materi ent of the It is airplane cr years later, i elocity wave changes are ructural leve n, can be ob ate. The tem uminium, co rmation me experiments an unknown e Mattei fore xplosion. anical twin d e which was t d on the grou ascapè in Pav a tree (Figs. 1 me in the ENI cise recording Pavia Court r et-executive, (Fig. 5). urred in 1994 rmo (Sicily) tr t alii, Frattura ed attei’s ca Matteis, Ch iali e Ingegneri talian oil con rashed on th implied com es emanating induced by el multiple s bserved. The mperature w opper and go echanism is are incorpo explosive ev ensic case, r deformation; taking back to nd minutes fr via county, bo 1, 2), his skin I President pi g of the exac ruling that the the airplane h 4, under the im rial. d Integrità Strutt ase was hiara Pozzi ia Chimica, C nglomerate, E he ground du mplete re-exa g from a sma an explosio slip bands o e occurrence wave may als old alloys are eligible for orated into t vent. reaching the Pressure wa o Milan Enri from landing ordering the M -stripped left ilots’ team, w ct location of e aircraft had had been deli mpulse of Pu turale, 14 (2010) solved i C.so Duca degli ENI, was ab ue to a then amining of th all charge ex on and by th or mechanica e of either o so cause su e analysed. r different F the evaluatio e conclusion aves; Stackin co Mattei, the at the Milan L Milan county t hand, high o was very exper f each finding fallen by an u ivered to EN ublic Prosecu ) 81-92; DOI: 10 li Abruzzi, 24 bout to land n unexplaine he theories o plosion. he resulting s al twins, ind ones depend urface alterat FCC metals on of micro that the air ng faults ene e then Presid Linate airpor y in Lombard on a branch. rienced with g and ended p unexplained a NI in Novemb utor Vincenzo 0.3221/IGF-ESIS. 4, 10129 Tori in Milan Lin d accident. T on macrosco shear stresse duced from d on the type tions. Differ and alloys ostructural si rcraft had fa ergy; Explos dent of the Ita t. It ended up dy. Wrecks of 11260 cumul piled up (Fig accident. ber 1961 (Fig o Calia, follow 14.09 81 rino, nate The opic es in the e of rent are igns allen ion; alian p on f the ated g. 3), g. 4). wing http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it D. 82 No the Fur an A c clea sea Firrao et alii, Fr ot too much e broken gold rthermore, a ENI employ coroner auto arly pertainin ated on the ba Figure rattura ed Integri had been left d family ring ( dashboard in yee and kept o opsy perform ng to the airc ack left seat (F e 1: October 2 (Blac Figure 2 ità Strutturale, 1 ft available fo (Fig. 6), his w nstrument (Tr on his desk w ed on the co craft, as well Fig. 5). 27, 1962: Matte ck and white ph 2: Aircraft wrec 14 (2010) 81-92 or further inv watch and brie riple Indicato within its steel orpses of M as a leg of th ei’s aircraft falls hotographs fro ckage by a line Figure 3: Pi 2; DOI: 10.3221/I vestigations, m efcase, a few d or, Fig. 7) had case (Fig. 8), attei and Ber he third pass s in Bascapè (P om original po e of tree border iled up retrieve IGF-ESIS.14.09 mainly person documents. d been gather , as a souveni rtuzzi allowed senger, an Am Pavia county), lice ones, taken ring a field in B ed wreckage. nal object pre red in the mo ir. d to retrieve merican journ 15 km from n in the same n Bascapè (Pavia eserved by th orning of Oct inside them nalist, Mr. Mc Milan Linate A night). a county). he Mattei Fam tober 28, 1962 metal fragm c Hale, who Airport mily; 2 by ments was http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it F F An exa and Figu Figure 5: Cockp right front William M Figure 7: A trip n explosion o amined by op d heat wave. ure 4: The plan 7 pit of the execu seat by the pil Mc Hale, was s talking wit ple indicator fro on board hav ptical and elec In fact, usual ne twin to the c 60 B model. B utive jet plane. lot. An Americ eated behind t th Mr. Mattei. om the fallen a ving been alw ctronic micro l signs of exp D. Firrao et crashed one. T Both the planes . Mattei was in can journalist, the pilot and aircraft dashbo ways suspecte oscopy to asc plosions, i.e. e t alii, Frattura ed The aircraft wa s had been com n the F oard. Fig ed, metal sect certain the pr evident macro d Integrità Strutt s a double-jet e mmissioned in Figure 6: The b gure 8: The trip tions of retri esence of latt o deformation turale, 14 (2010) executive plan November 196 broken ring of M the family me ple indicator ca ieved objects tice deformat ns induced b ) 81-92; DOI: 10 e, Morane Sau 61. Mr. Mattei retr emorabilia. ase with stainle s were carefu tion signs du y explosion, 0.3221/IGF-ESIS. ulnier, rieved among ess steel screws ully prepared e to the pres partial meltin 14.09 83 s. and sure ng at http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it D. 84 gra in t bod Th alo Th wa of RE Mi sur the cha In obj Mo fav can Mic ban spe latt Inh wav Tem ten hen inc the Va wav T Firrao et alii, Fr ain boundarie the objects re dy liquids dur he metallograp ongside the alu he screws and s on the uppe the centre of EVIEW OF PR icrostructural ef he revie focused Inside a rface, is reflec e critical shear arge is high, t the case of s jects placed q oreover, if th vourably orien n appear in iso crostructural nds. Dependi ecific alloy di tice modificat homogeneous ve [2], micros mperature ef ndency to loca nce equally lo crease. The co e compression rious recrysta ves as well as T rattura ed Integri es, gas washin etrieved fairly ring the more phic investiga uminium allo the ring coul er left corner f the dashboar Figure 9: Th REVIOUS WO effects of an exp ew has been l . a metal compo cted as a tens r stress for sl the maximum small charges quite close to he distance is nted crystals olated favour signs detecta ing on the ch ictate which tions. s distribution scopic examin ffects may als alised plastic ocalised micro orresponding n wave are fa allization stag s on the actu ità Strutturale, 1 ng on surface y intact or on e than thirty y ation then fo oy fragments r ld be position of the dashb rd. he triple indica ORK xplosion on FC limited to FC onent the pri sion wave. Bo lip or mechan m stress is reac the overpres o the charge. s fairly high i and can prop rable oriented able by micro harge mass a of the above ns of twins in nations have so affect the deformation ostructural va material bein cilitated owin ges can be en al material re 14 (2010) 81-92 or rolled edg n surfaces of years elapsed cused on the retrieved from ned fairly well board (Fig. 9), tor was positio CC metals CC metals, giv imary overpre oth the comp nical twinning ched; then the ssure does no As the targe in respect to pagate to the d grains at or oscopy inside and the targe e two morph nside the com to be as thor microstructu in thin bands ariations. Asi ng less stable, ng to the redu nvisioned dep ecrystallization 2; DOI: 10.3221/I ges developin the fragment since the cor e gold ring an m the bodies. l on the aircra , the left Matt oned on the up ven the type essure wave y pression wave g. In the case e material bre ot cause break et-to-charge d the scale of e nearest ones close to the c e the crystals et-to-charge d hologies preva mponent havi rough as poss ure. It is kno s (shear band ide from this , recrystallizat uced recrystall pending on th n temperature IGF-ESIS.14.09 ng at external ts retrieved in rpse burials. nd the stainle aft scene at th tei hand with pper left corner of alloys on w yields a comp e and the ref of objects qu eaks up, usual kage, but can distance incre f the phenom s. In the extr compression w can be eithe distance, crys ails. X-ray di ing be detecte ible. own that in h s) is present, , all crystal d tion phenom lization temp he intensity o e: (i) no recry surface of fra n the bodies, ss steel screw he moment o h the ring was r of the airplan which the fo pression wave flected wave m uite close to t lly by delamin n cause comp eases, only la menon, lattice reme case, on wave impinge er mechanical stal habit and iffraction ana ed in respect high strength with a very lo eformations mena under th perature. of both overp ystallization; ( acture zones which had b ws of the trip of the acciden s probably sta ne dashboard. rensic investi e, which, upo may cause th the explosive nation [1]. pressive plasti attice deforma e deformation nly a few plas ed surface. l twins or he d stacking fau alysis may be t of the incid steels or Al ocalised temp induce a loca e temperatur pressure and (ii) limited re were not pre been corroded ple indicator c nt: the instrum aying just in fr igation had to on reaching a he overcomin e charge, or if ic deformatio ation may oc n is restricted stic deformati eavy multiple ult energy of useful to de dent overpres alloys a pecu perature raise al internal en e wave follow overtempera crystallization esent d by case, ment front o be free g of f the on in ccur. d to tions slip f the etect sure uliar and ergy wing ature n (at http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it gra rec If c twi evi Du exp Cry In res Th the roo to 4 Th inc less me wh As kno wit han at t val for the 13 Th val c,tw Co tem mJ 16% Me sho fac to C It c def In def the der *Va ain boundarie crystallization complete recr inning or mu ident in zones ue to the lack plosion, it can rystal deformat single crystal olved shear s he critical reso e elastic shear om temperatu 4 MPa for co he critical she crease its valu s in the FCC etals (almost n hen d/dt incr it regards m own early fr th crystals ori nd, debate to the end of th lues are listed r silver, 100 M e alloys at 75% MPa for tin hus, the critic lues than c,slip win is mainly i ontrary to c,s mperature as d /m2 per ever % Cr and 13% etals and meta ow the highes cilitate twinnin Cu lowers sf can be conclu formation me polycrystals, formation me y = f e known form y,tw =  rived for twin alues of sf may es) with a du and grain gro rystallization ultiple slip. D s closer to the k of well orga n be useful to tion mode: slip ls the compe stresses, the lo olved shear st r modulus; c ures and quas opper alloys an ear stress c,sli ue); it is also C and HCP on null in Al) an reases, the slip mechanical tw rom an histor rientation date decide wheth he Fifties, beg d afterwards: MPa for gold, % Au [6]. Fo and from 210 cal resolved s p. In fact, in c nfluenced by slip, c,twin doe does sf [7]. I ry temperatur % Ni, sf chan al alloys havin st sf values a ng deformatio f as its percen uded that on echanism in s which usua echanisms is g fs + ks (d-1/2) mula for slip a ftw + ktw (d-1 nning. y differ from th ual grained s owth. is attained w Due to the tem e detonation anised inform o further inves versus twinni etition betwee ower being th tress for slip, c,slip strongly i sistatic deform nd 3 MPa for ip is highly in affected by th nes. As a ma nd more pron p critical shea winning, one rical point of es back to 19 her a similar c ginning of the about 150 M between 50 a or the sake o 0 to 300 MPa shear stress f common tens y the stacking- es not vary w n fact, as it re re degree in a nges from 14. ng high sf va s reported in on: a 30% Zn ntage increase nly at low tem ingle crystals ally compose governed by t and 1/2) hose reported D. Firrao et structure; (iii) with the overp mperature att front inciden mation on mec stigate these k ing en slip and m he one that pr hereafter indi increases upo mation rates r aluminium a nfluenced by he temperatu atter of fact, i nounced in all ar stress rema has to note f view, so tha 931 [4], even critical comp e Sixties, it wa MPa for copp and 100 MPa f comparison a for pure iro for mechanic sion tests, me -fault energy, with the defo egards Cr-Ni a range betwe .5 to 10 mJ/m alues will def Tab. 1*. On n brass plastic s. mperatures an . e common o the respective in the Tab. 1 i t alii, Frattura ed ) complete r pressure wave tenuation insi nce point. chanical twin kinds of defo mechanical tw redominates i icated as c,slip on lowering t (10-510-1 s-1) alloys, with th composition ure (it increas in close-pack loys, as stainl arkably increa that the exis at Schmidt’s n before the e onent for me as possible to per, 55-90 MP a in silver-gold n, values from n at 15 K. cal twinning, echanical twin sf, and incre ormation rate i stainless stee een 400 and 2 m2 passing fro form mainly b the contrary, cally deforms nd very high d objects under e Hall-Petch t if measuremen d Integrità Strutt recrystallizatio e being still a ide the mater ns and multip ormation mec winning is rul in objects exp p, has values i the temperatu ), maximum v he minimum n variations (e ses for decrea ed metals the ess steels. Th ses. stence of a c law, which a existence of d echanical twin o suggest som Pa for Cu-8.9 d alloys [5], w m 5 to 35 MP hereafter ind ns appear only eases as the la e and it seem el, there is a d 200 K [8, 9, om 300 to 20 by slip. This b , additions of by twinning deformation rgoing explo type relations nts taken by oth turale, 14 (2010) on with a to active, newly rial, recrystall le slip bands chanisms [3]. led by the re posed to a de in the vicinity ure or increa values for c,s ones being on even small tr asing tempera e increase of he deformatio ritical compo allows to dete dislocation w nning deform me values for 9% Al alloys, with data rang Pa have been dicated as c, y at higher ap atter increases ms to mildly decrease of s 10]. In partic 00 K. behaviour is o f alloying elem easier than C rates mechan sions, the co ships [11, 12] her authors are ) 81-92; DOI: 10 tally fine str formed cryst lization phen in FCC meta espective valu tonation fron y of 10-410-5 sing the defo slip vary from ne order of m races of forei atures) mostly  with 1/T i on rate has a onent of shea ermine the lo were postulate mation existed critical twinn , 300 MPa fo ging from 75 suggested fo ,twin, has usua pplied stresses s. decrease up sf values betw cular, for a st observed in A ments causing Cu, because th nical twinning ompetition b , namely e taken into acc 0.3221/IGF-ESIS. ructure; (iv) t tals may unde nomena are m als undergon ues of the cri nt. G, with G b ormation rate 8 MPa for st magnitude low ign atoms hi y in BCC me is limited in p similar influe ar stress, c, oad to be app ed. On the o lasted long; o ning stress. Th or nickel, 50 M and 100 MPa or zinc, from ally much hig s than slip ba pon lowering ween 0.05 and tainless steel w Al and Ni, wh g a decrease o he addition of g is the favou between the (1) (2) count. 14.09 85 total ergo more e an itical eing e. At teels wer. ighly etals, pure ence; was plied other only hose MPa a for 4 to gher ands. the d 0.1 with hich of sf f Zn ured two http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it D. 86 Th wh red Th not Cas be Th Cu rate Pet con twi alw Als app 23 wh par gra coe qua Firrao et alii, Fr he Peierls-Nab hereas the ana duces with the herefore, at hi t too high. ses referring usually encou he Eqs. 1 and u, Meyers et al e for low val tch straight li nditions fine g inning. Analo ways favoured Fig so for stainle proaching the to 187 m w hereas the sh rticularly evid ain dimension existence of aternary Co a rattura ed Integri M Al Cu Br Br Au Ag N Au Au Au Table 1: barro stress f alogous stress e temperature igh deformati to Cu, Al, Au untered when d 2 can be rep l. [13] sugges lues of applie ine for slip to grain copper ogous conside d at all grains gure 10: Hall-P ess steels (AI e yield point, were either co hock loaded o dent in the sm ns decrease. mechanical t alloys (contain ità Strutturale, 1 METALS AND l u rass (10% Zn rass (30% Zn u g i ustenitic stain ustenitic stain ustenitic stain Stacking-fault for slip, fs, d s, ftw, followi e. ion rates, suc u and their all n exploring th presented by ted that ktw i ed elongation o move upwa (grain dimen erations are v dimensions b Petch plots for ISI 304) ktw especially if old rolled or s ones mainly maller grains. Thus  can twinning and ning respectiv 0 100 200 300 400 500 0,05 F lo w s tr es s [M P a] 14 (2010) 81-92 D ALLOYS n) n) nless steels AI nless steels AI nless steels M energy (sf) va depends on t ing the path s ch as those u loys, as well a he possibility straight lines s about twice ns, but an inc ards parallel t nsions lower t valid also for because brass r plastic flow sl as sugges is about twi grains dimen shock loaded exhibit twinn For the tran n become lo d  martensit vely Ni, Ni an 5 0,1 0,15 2; DOI: 10.3221/I ISI 304-316 ISI 310 Mn-Cr alues of some m the temperatu set for by c,tw usually encoun as stainless st of bomb exp s having ks an e as ks. The v rease of the to itself, inter than 50 m) u r brasses; her -ftw is quite lip (10-3, 103 an sted by Meyers ice as ks at 1 nsions exceed d [14]: in the c ning, accomp nsformation  ower than ft te was observ nd Cr, and Ni 0,2 0,25 d-1/2 [µm-1 IGF-ESIS.14.09 sf v metals and allo ure and defo win, does not d ntered in exp teels, are here plosions as the nd ktw as ang values of ks is deformation secting the st undergoes slip re, unlike cop smaller than nd 106 s-1) and et al. [13]. 1 and 5% de d 55 m. Sam cold rolled sa panied by th    a  te ftw when crys ved during t i, Cr and Mo) 0,3 0,35 1/2] Tw Hy 10 Sl 10 Sl 10 Sl values (mJ/m2 166 80 35 15 42 21 128 21 40 11 oys at room tem ormation rate depend on th plosions, y c eby analyzed, e cause of an gular coefficie s not much in rate, from 10 traight line fo p, whereas co pper, in the c Cu-ftw. twinning (Hyp eformations mples with gra amples slip is he formation ension is nece stals are belo tension tests ) and on Mn- 0,4 winning ypothetical 0E6 (1/s) lip 0E3 (1/s) lip 0E-3 (1/s) lip 2) mperature. in a manner he deformatio can go over  since metals aircraft crash ent, respective nfluenced by 0-3 to 106 s-1, or twinning (F oarse grain co case of explo pothetical) for levels and it ains dimensio the only way of platelets essary, whose ow a certain on FCC bin Cr-C stainles r similar to  on rate and m y,tw if this on of their kind h. ely. As it reg the deforma makes the H Fig. 10). In th opper deform osion, twinnin Cu, increases, w ons varying f y of deformat of  marten e value lower dimension. nary, ternary s steels [15]. c,slip, ildly ne is can gards ation Hall- hese ms by ng is while from tion, nsite, rs as The and http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it Go wit thin trea A v If tran mo Sum Th low aus acc ten Th onl a s dep CO Ca in ins Fi Ins of der An bec F old alloys hav th intermedia n twins was atment after c very fine twin there is the nsformation orphology in w mmary of the he above cons w fs values a stenitic stainl companied by ndency to twin he explosions ly in a few in tress parame pending on th ONSIDERATI alculations of cr or Al an deforma subject t the case of A ide an Al-allo igure 11: Thin ring, observe (NH4)2S2O stead, as it reg  martensite. rive approxim n approximate coming infini c,twin = F ve a behaviou ate values bet detected; the cold working n retrieved in contempora AuCuI+ which the det review of the eff siderations all and high sf v less steels, w y platelets of nning deform caused by a dividual grain eter macrosco he deformatio IONS AND C ritical resolved nd Al alloys, ation is practi to deformatio Al we must c oy fragment r twins formed i ed by Scanning O8 (10%)+NaC gards austenit In the literat mate values ta e relation bet itesimal when sf/ 2b1 ur to deform tween that of ey had a ver g [16]. the Mattei go ary presence +1 (being  tection of thi ffects of explos low to derive values, show which are c f  martensite mation of Au- small charge ns or groups opically deter on mechanism CALCULATIO d shear stress fo c,slip is to b cally impossib ons with spee consider a c, etrieved durin in the Mattei g g Electron Micr CN (10%) solu tic stainless s ture no suitab aking into acc tween c,twin a n the distance D. Firrao et ation very sim f Cu and bras ry different m old alloy ring of silver an 1 a FCC dis n twins may b sions on metals e some conclu slip band fo characterized e. Also Cu an -Ag alloys is in do not prod of grains dist rmined, like t m identified b ONS APPLIED for twinning e taken into ble. c,slip incr ds up to 55 s ,slip range var ng the corone gold alloy (18 c roscopy; etchin ution in water. teels, we mus ble c,twin value ount some of and sf is deriv among the d t alii, Frattura ed milar to that ss itself. In p morphology c is illustrated nd copper in sordered silv be more diffi ls usions about ormation, eve by low sf nd brass are ntermediate b duce consider tant one from the yield stres by metallograp D TO THE FO account bec reases due to -1 show an in rying at least er autopsy of carats) ng: Fig st refer to c,t es were found f the sf value ived from tha dislocations in d Integrità Strutt of brass, hav articular in a compared to in Fig. 11 [3] n an 18 car ver rich solid icult. metals under en at very hig values, mec subject to tw between the o rable deforma m another. In ss, but it is n phic observat ORENSIC CA cause they ha high deforma ncrease of yiel between 0.6 f Mr. Mattei’s gure 12: Multip fragment re Mr. twin, even if th d for austenit es listed in Ta at advanced b ncreases: turale, 14 (2010) ving a stackin gold alloy (1 o twins obtain . at gold alloy solution) wi rgoing an exp gh deformati chanical twin winning, mor ones of Cu an ations in met such a situati necessary to c tions. ASE ave high sf v ation rate eff ld stress of m and 6 MPa. corpse are vi ple slip bands etrieved during Mattei’s corps here might be tic stainless st ab. 1, as show by Suzuky an ) 81-92; DOI: 10 ng fault energ 17% Ag) the ned subseque y, it is possi ith a charact plosion. Al an on rates. On nning is ind re favoured i nd brass. tals and may ion it is impo consider eith values and th fects: tests on more than 100 Multiple slip isible in Fig. 1 formed in an a g the coroner a se: Keller etcha e the contemp teels; howeve wn below. nd Barrett [6], 0.3221/IGF-ESIS. gy quite low presence of v ent an annea ible to obtai teristic thin p nd its alloys, w n the contrary duced, eventu in the latter. leave their ef ossible to refe her c,slip or c herefore twinn Al monocrys %. Conseque p bands dete 12. aluminium allo autopsy of ant. porary forma er it is possibl , omitting a t (3) 14.09 87 and very aling in a plate with y, in ually The ffect er to c,twin, ning stals ently cted oy ation le to term http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it D. 88 wit wh An wit wh Fur equ test Fin plo stra calc Val the = 0 If calc [21 ste of rep By foll Firrao et alii, Fr th b1 = ao/6 here b1 is the B nother relation (1/3)( th b = ao2/ here b is the B rthermore, R uation (4) and ts on monocr nally, a perfec otting data of aight line pas culated from lues of c,twin, e four above m 0.31, whereas more recent culations by I 1] into the equ el containing the screws o ported in Tab making simi lowing Tab. 3 Alloy Stainless Steel (AISI 304) M C aus rattura ed Integri 6 Burgers vecto n is derived b (1/3 + k·c,twi /2 Burgers vecto Remy and Pin d the other o rystals and po ct linear corr f every FCC m sses through unknown sf , derived for mentioned m s ao was taken calculations Inakatsu [20] uation propo g about 3.5% of the Triple . 2. ilar calculatio 3 can be furth Hypothesiz sf (mJ/m2) 20 15 10 Table 2: C Metal or alloy Copper Au-Ag alloy Cu containing stenitic stainle steel Table 3: Cri ità Strutturale, 1 or of the Shoc by Remy and P in /G) c,twin / r of a perfect neau [17] com one plotting o olicrystals. Wi relation can b metal for wh the origin a f data [3, 18]. austenitic sta methods, are l n as 0.359 nm are perform ], and incorpo sed by Rhode Cu [18]: 31.3 e Indicator (A ns basing on her derived [1 zed Suzuk Barrett 6 5 3 Critical resolve as a function o y Hypo (m g ess itical resolved s 14 (2010) 81-92 ckley semi-dis Pineau [17], u /G = sf/G·b t dislocation. mpared two c on the ordinat ith the second be traced put ich the perta and its angul ainless steel h listed in Tab. m. med by takin orating more es and Thom 3 mJ/m2. Not AISI 303) th n Suzuki and 18]. ky and t, Eq. 3 R 68 51 34 ed shear stress of staking fault othesized sf mJ/m2) 80 70 60 45 40 35 20 25 30 shear stress for from γsf using 2; DOI: 10.3221/I slocation and using a formu b curves relatin te axis c,twin e d plot other p tting on a dia aining sf and lar coefficien hypothesizing 2; G was ob ng into accou recent Gonz mpson [22], a m t considering he value falls Barrett [6], o Remy and Pine Eq. 4 81 70 55 for twinning ( t energy sf der Suzuky a Barrett 272 238 204 135 120 105 67 84 101 r twinning (c,t g formulas by v IGF-ESIS.14.09 d ao is the latti ula proposed ng c,twin /G t experimental possible value agram sf in o c,twin values t is 0.452. T g three increa tained as 73,6 unt both dat zales et al. res more precise g Cu, which w to only 21 or Remy and c,twin (MP eau, Rem exp (c,twin) for aust rived by differe c,t and t Remy Pin 17 16 15 9 9 8 10 11 13 twin) for various various authors ice constant. by Venables to sf/G·b: o data, obtaine es of c,twin ca ordinate and are available Then, unknow asing sf value 660 MPa assu ta by Choi e sults on the e value of sf c was in a small mJ/m2, whic Pineau [17], Pa) my and Pineau erimental dat 103 81 66 tenitic stainless ent methods [3 twin (MPa) y and neau Li 75 63 50 98 92 86 04 18 31 s metals or allo s. [5]: one with c,tw ed by several an be comput the twin-crs in the literat wn c,twin valu es in the 10-2 uming E=193 e Jin [19], w effect of Cu i can be obtain l quantity in t ch confirms or Firrao et u ta Experi co s steels and 3]. inear correlati 177 155 133 100 88 77 44 55 66 oys calculated (4) win derived by researchers w ted. ss in abscissa ture. The deri ues can be ea 20 mJ/m2 and 3,000 MPa an who started f in stainless st ned for a stain the stainless s the assumpti al. [3] works mental linear rrelation 44 33 22 ion y the with and ived asily d by nd  from teels nless steel ions s the r http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it Ca Th the the In TN De To the Pre bec ma Ref gra exp Val in T 0.3 By cha alculation of p he calculated p e charge used e reflected ma particular in NT are report D etermination of relate maxim e above exper Table 5: Po essure waves come stronge aterial. ferring to the ains, thus ind plosion wave max = ( lues of maxim Tab. 6, using 345 for alumin Distance [m] 0.1 0.2 0.3 0.4 0.5 comparing d arge from an pressure waves pressure valu d in the exper aximum press Tab. 4, the r ed. Distance [m] 0.42 0.68 f the target-to c mum effective riment and as Distanc [m] 0.1 0.2 0.3 0.4 0.5 ossible effective impinging on er. For this r e hypothesis t dicating that may be evalu (3(1-2))Pmax/ mum shear st the following nium and its a e Effectiv Pmax [MP >250 97.2 35.6 20.2 14.6 Table 6: Ma data from Tab object inside induced by an es subsequen riment. For th sures, as recor results of an e Calculated air [M 2 0 Table 4 charge distance e pressure wi ssuming that a ce Pmax i [MP >1 6 2. 1.2 0. e pressures imp n an object m eason a facto that, in the ca the material uated using th /(2(1+)) tresses in diff g values for t alloys, 0.44 fo e Pa] max in st steel (= [MP >12 50. 18. 10.4 7.5 aximum shear s or b. 2, 3, and 6 e which mech D. Firrao et n explosion nt an explosio he purpose of rded by a det explosion exp pressure in MPa] 2 0.8 4: Free air and r e ith distance c a charge equiv in air Pa] E 16 6 .2 25 .9 pinging on an move through or equal to 2 ase of a small l general yiel he following f ferent materia the Poisson m or gold and it tainless =0.28) Pa] ma ste 29 .1 .4 42 53 stresses arising riginating from it is then pos hanical twin ev t alii, Frattura ed on in free air f calculating t tector, are mo periment mad Maximum reflected press alculations w valent to 150 Effective (x9) [MPa] >144 54 19.8 11.25 8.1 object after an the bulk and has been us charge, slip o lding has not formula which als that may b modulus: 0.28 ts alloys, 0.343 ax in stainless eel (=0.31) [MPa] >109 42.3 15.5 8.8 6.3 g in various me m a 150 g TNT ssible to deriv vidence is dis d Integrità Strutt depend both the intensity ore important de using an e reflected pre [MPa] 14.4 7.2 sures at small d were made, us 0 g of TNT w ) Pmax n explosion of d can be refle sed to obtain or twin defor t been reach h is valid in th be hit from an 8 and 0.31 for 3 for copper max in alluminiu [MPa] >86 33.6 12.3 6.98 5.04 etals after impi charge explosi ve the approx scovered. Dat turale, 14 (2010) h on the targe of pressure w t and always h xplosive char essure Mu distances. sing multiplyin was exploded ( Effective (x7 [MPa] >115 43.2 15.84 9 6.48 a 150 g TNT c cted from fre a plausible m rmation may b hed, maximum he elastic ran n explosion i r stainless ste and its alloys n um max in [MP >3 12. 4.4 2.5 1.8 ingement of pr ion. ximate distanc ta in the first ) 81-92; DOI: 10 et distance an waves imping higher than th rge correspon ultiplying fact 7.2 9 ng factor dat (Tab. 5). 7.2) Pmax ] 4 charge at vario ee surfaces, th maximum pr be manifested m shear stre nge: n an aircraft eel, both repo . n gold Pa] max 31 .15 45 52 82 ressure waves ce of an explo two columns 0.3221/IGF-ESIS. d on the mas ging on an ob he free air on nding at 364 tor ta, obtained f ous distances. herefore they ressure inside d only in isol ess caused by are also repo orted in literat in copper [MPa] >88 34.1 12.5 7.1 5.1 osive 150 g T s of Tab. 6 ar 14.09 89 ss of ject, es. g of from y can e the lated y an orted ture, TNT re in http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true http://www.gruppofrattura.it D. 90 com stai AP OF twi twi M Firrao et alii, Fr mplete agreem inless steel, co PPLICATION F THE TRIPL etallo mech The ins could be ins, as illustra Figur M rattura ed Integri ment with th opper, gold, a N OF DEVELO LE INDICATO ographic obs hanical twins above can be still be obser ated in Fig. 11 Figure 13: T re 14: Twins in Figure 15: N ità Strutturale, 1 he results of and aluminium OPED THEO OR CASE ervations of in isolated gr e rationalized rved in a stain 1, was at the l Twins in isolate n isolated grain No twins detec 14 (2010) 81-92 f recent expe m alloys disk ORIES TO TH f the section rains at the su d by inferring nless steel ob limit of its ow ed grains at the ns at another p cted below the 2; DOI: 10.3221/I riments perfo s [23-25]. HE STAINLE of a stainle urface (Figs. 1 g that the scr bject. By the wn sphere. e surface of a s point of the sur surface of a st IGF-ESIS.14.09 formed by th SS STEEL OF ess steel scre 13 and 14) and ew was at th same token a stainless steel s rface of a stain tainless steel sc he authors by F THE SCREW ew allowed t d no twin bel he limit of the also the gold crew of the tri less steel screw crew of the trip y exposing to WS to ascertain low the surfac e sphere in w ring with sc iple indicator. w of the triple i ple indicator. o a small ch the presence ce (Fig. 15). which mechan antily observ indicator. arge e of nical vable http://www.gruppofrattura.it http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true By the at l cha WH the In Aft com the retr sol A f an pos of i A considering eir pressures b least doubled arge the distan HERE WAS T s it was Fig. 16. Then th e air most of i that position ter the calcula ming from th e position of rieved high o lution of the c final visit to t Italian indust sition could e it. A that the clos by multiple re d. From the a nce charge-to THE BOMB P s said before . he two sphere its perimeter the bomb ha ations the co he yellow-red f Mattei’s han on a tree bra case. the twin plane trialist, confir easily be reach Figure 1 e space of th eflections, dis above calculat o-screw could PLANTED? the locations es centered o but a small p ad been plant roner remem leverage in th nd and that anch in the m e stationing in rmed that, by hed by hand 16: Reconstruc D. Firrao et he cockpit can stances comin tions and con d be 40-45 cm s of the screw on the tips of ortion behind ted from the e mbered that he he middle of the bomb h morning of n a Nice Airp y entering from to plant a sm ction of the co Figure 17: For t alii, Frattura ed nnot be cons ng from the c nsiderations it m and the dist ws and of the the arrows ha d the dashboa exterior of th e had found a the lowest pa had been pla October 28, port hangar an m a small ma mall explosive ckpit scene at rward portion d Integrità Strutt sidered simila combined con t was then po tance charge-t e gold ring wh ad a circumfe ard. he cockpit (Fig a small yellow art of the das anted behind 1962, had g nd belonging anhole on the e charge behin the moment o of the fuselage turale, 14 (2010) ar to a free sp nsiderations o ossible to con to-ring could here fairly we erence as an in g. 17). w piece embe shboard. Such d the dashbo given its final at the time o e right of the nd the dashb of the charge ex e. ) 81-92; DOI: 10 pace, and tha of Tab. 2, 3, nclude that w d be 20-25 cm ell positioned ntersection. S edded in Matt h a revelation ard. The ski l contribution of the forensic forward fusel oard in the ce xplosion. 0.3221/IGF-ESIS. at waves incr and 6 have to with a 150 g T m. d, as illustrate Such a line lie tei’s hand, cle n confirmed b n-stripped h n to confirm c investigatio lage, an adeq enter of the b 14.09 91 rease o be TNT ed in ed in early both and, m the n to quate back http://www.gruppofrattura.it http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true D. 92 CO LIS [1] [2] [3] [4] [5] [6] [7] [8] [9] [10 [11 [12 [13 [14 [15 [16 [17 [18 [19 [20 [21 [22 [23 [24 [25 T Firrao et alii, Fr ONCLUSION he Matt of the p ST OF REFE G. E. Diete C. S. Smith, D. Firrao, G E. Schmidt, J. A. Venab N.Y., (1964 H. Suzuki, C L. Remy, A R. M. Latan F. Lecroisey 0] F. Lecroisey 1] N. J. Petch, 2] E. O. Hall, 3] M. A. Meye 4] H. J. Kesten 5] L. Remy, A 6] S. Appleton 7] L. Remy, A 8] D. Firrao, P 9] J. Y. Choi, W 0] N. Inakatsu 1] M. Gonzale A, 343 (200 2] G. Rhodes, 3] Firrao, P. M R. Montana 4] D. Firrao, (2009)76. 5] D. Firrao, P T rattura ed Integri N tei affair had lane. RENCES er, Mechanica , Trans. M.S. G. Ubertalli, a , G. Siebel, Z bles, in Defo 4) 77. C. Barrett, Ac . Pineau, B. T nision, A.W. R y, B. Thomas y, A. Pineau, , J. Iron Steel , Proc. Phys. ers, U.R. And nbach, M.A. M . Pineau, Met n, G.E. Dieter . Pineau, Mat P. Matteis, C. W. Jin, Script u, H. Yamamo ez, C.S.B. Cas 03) 51. A.W. Thomp Matteis, G. Sc ari, M.E. Tata P. Matteis, C P. Matteis, C. ità Strutturale, 1 been solved: al Metallurgy, AIME, 214 ( and E. Corda Z. Elektrochem rmation Twi cta Metall., 6 Thomas, Mat. Ruff, Metall. T s, Phys. Status Metall. Trans Inst., 174 (19 Soc., B64 (19 drade, A.H. Ch Meyers, Meta tall. Trans. A, r, M.B. Bever t. Sc. Engnr., Pozzi, Acc. S ta Materialia, oto, M. Ishio stro, V.T.L. B pson, Metall. avino, G. Ub a, G. Brandim C. Pozzi, M.G Pozzi, Mater 14 (2010) 81-92 a small charg McGraw-Hil (1958) 574. no, Technolo m., 37 (1931) nning, R.E. R (1958) 156. . Sc. Engnr., 3 Trans., 2 (197 s Solidi A, 2 ( s., 3 (1972) 38 953) 25. 951) 747. hokshi, Meta all. Trans. A, 7 , 5A (1974) 1 rs, Trans. M.S 26 (1976) 12 Sc. Torino - M 36 (1996) 99. , J. Japan Inst Buono, J.M.C Trans. A, 8A bertalli, C. Po marte, S. Petra G. Ienco, G rials Science F 2; DOI: 10.3221/I ge bomb had ll Kogakusha ogy, Law and 447. Reed, J.P. Hi 36 (1978) 47. 71) 505. (1970) K217. 87. all. Mater. Tra 7A (1976) 19 963. S. AIME, 221 3. Mem. Sc. Fis. . t. Metals, 48 ( . Vilela, M.S. A (1977) 1901 zzi, M.G. Ien alia, Metall. an . Pellati, M.R Forum, 638-6 IGF-ESIS.14.09 d been plante , New York, Insurance, 4 irth, H.C. Ro ans. A, 26 (19 43. 1 (1961) 90. Ser. V, 29 (2 (1984) 71. Andrade, J.M . nco, P. Piccar nd Mater. Tra R. Pinasco, R 642 (2010) 102 ed behind the N.Y., USA, ( (1999) 23. ogers eds., G 95) 2881. 2005) 3. M.D. Moraes, rdo, M.R. Pin ans. A, 38 (20 R. Montanari, 29. e dashboard f (1976) 51. Gordon & Bre , M.J. Mantel, nasco, E. Stag 007) 2869. , M.E. Tata, from the exte each, New Y , Mater. Sci. E gno, G. Costa CALPHAD erior York, Eng. anza, , 33 http://www.gruppofrattura.it http://dx.medra.org/10.3221/IGF-ESIS.14.09&auth=true << /ASCII85EncodePages false /AllowTransparency false /AutoPositionEPSFiles true /AutoRotatePages /None /Binding /Left /CalGrayProfile (Dot Gain 20%) /CalRGBProfile (sRGB IEC61966-2.1) /CalCMYKProfile (U.S. Web Coated \050SWOP\051 v2) /sRGBProfile (sRGB IEC61966-2.1) /CannotEmbedFontPolicy /Error /CompatibilityLevel 1.4 /CompressObjects /Tags /CompressPages true /ConvertImagesToIndexed true /PassThroughJPEGImages true /CreateJobTicket false /DefaultRenderingIntent /Default /DetectBlends true /DetectCurves 0.0000 /ColorConversionStrategy /CMYK /DoThumbnails false /EmbedAllFonts true /EmbedOpenType false /ParseICCProfilesInComments true /EmbedJobOptions true /DSCReportingLevel 0 /EmitDSCWarnings false /EndPage -1 /ImageMemory 1048576 /LockDistillerParams false /MaxSubsetPct 100 /Optimize true /OPM 1 /ParseDSCComments true /ParseDSCCommentsForDocInfo true /PreserveCopyPage true /PreserveDICMYKValues true /PreserveEPSInfo true /PreserveFlatness true /PreserveHalftoneInfo false /PreserveOPIComments true /PreserveOverprintSettings true /StartPage 1 /SubsetFonts true /TransferFunctionInfo /Apply /UCRandBGInfo /Preserve /UsePrologue false /ColorSettingsFile () /AlwaysEmbed [ true ] /NeverEmbed [ true ] /AntiAliasColorImages false /CropColorImages true /ColorImageMinResolution 300 /ColorImageMinResolutionPolicy /OK /DownsampleColorImages true /ColorImageDownsampleType /Bicubic /ColorImageResolution 300 /ColorImageDepth -1 /ColorImageMinDownsampleDepth 1 /ColorImageDownsampleThreshold 1.50000 /EncodeColorImages true /ColorImageFilter /DCTEncode /AutoFilterColorImages true /ColorImageAutoFilterStrategy /JPEG /ColorACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /ColorImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000ColorACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000ColorImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasGrayImages false /CropGrayImages true /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.50000 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /GrayImageDict << /QFactor 0.15 /HSamples [1 1 1 1] /VSamples [1 1 1 1] >> /JPEG2000GrayACSImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /JPEG2000GrayImageDict << /TileWidth 256 /TileHeight 256 /Quality 30 >> /AntiAliasMonoImages false /CropMonoImages true /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.50000 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict << /K -1 >> /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile () /PDFXOutputConditionIdentifier () /PDFXOutputCondition () /PDFXRegistryName () /PDFXTrapped /False /CreateJDFFile false /Description << /ARA /BGR /CHS /CHT /CZE /DAN /DEU /ESP /ETI /FRA /GRE /HEB /HRV (Za stvaranje Adobe PDF dokumenata najpogodnijih za visokokvalitetni ispis prije tiskanja koristite ove postavke. 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