Microsoft Word - numero 14 articolo 7 M. 64 M Al M En ma AB inv the the eva par par mi pre the mi qu eva the KE IN par cau exp sol sol the stat par the (us vol liqu the geo I Merlin, Frattura Microstru Al-Cu san attia Merlin ngineering Dep attia.merlin@u BSTRACT. In vestigated by e realisation e alloy comp aluated. The rameter for rts of the cr croscopes, w esence of a e zones cha croscope w antitative m aluated and e examined a EYWORDS. A NTRODUCTIO n foundry componen long time. rticularly alum using the dev perimental po lidification, fo lidified. Unlik erefore, the al te the materia rticles, and th e solidus tem sually dendriti lume fraction uid film and s e presence of ometry of the I a ed Integrità Str uctural nd mou n partment, Univ unife.it n this paper y means of m of the castin position and e quantity o the crack he racks. The h which show liquid film, aracterised were statistic microstructur correlated t alloys. Al-Cu alloys; ON y practice th nts. Hot tearin Both ferrou minium alloy velopment of oint of view [ ollowing inter ke pure metal lloy consists al can be con hen as a mush perature, wh ic in shape). T n of solid is a solid bridges, f two contemp e mould. Firs rutturale, 14 (20 charact uld casti versity of Ferr r, the hot te microstructu ngs and thre d of differen of the eutec ealing pheno hot tear path wed that the in particular by the max cally analyse ral paramete to the capac ; Sand mould he occurrenc ng is one of t us and non- ys. Great effo hot tears; var [1-4]. Hot tea rdendritic and ls, alloys grad of both a liqu nsidered as a h when the g en the mater The growth o approximatel , as has been porary pheno stly, there is 010) 64-74; DOI terisatio ings rara, via Sarag earing behav ural examina ee Al-Cu allo nt pouring te ctic phase a omenon, in f hs and surfa e fracture su r at higher c ximum cros ed by mean ers of percen city of the eu d casting; H ce of solidifi the most seri ferrous alloy ort has been rious authors aring is related d intergranul dually transfor uid and solid slurry at the h grains starts t rial is in the m of a hot tear o y 85-90%, an suggested by omena, which the contracti I: 10.3221/IGF-ES on relate gat 1, 44100 viour in Al-( tion and ima oys with diff emperatures available dur fact the eute aces were ob urfaces were copper conc ss-section v ns of comm ntage, mean utectic liquid ot tearing; M fication defec ous solidifica ys can suffer n made over s have contrib d to the nucle ar paths insid rm from a liq d for a consid highest temp to interact wi mushy state, occurs in the nd it propaga y several autho h operate insi ion of the m SIS.14.07 ed to ho Ferrara (Italy (4.86)%Cu age analysis. ferent Cu an on the hot ring solidific ectic liquid f bserved by m e dominated centrations. variation an mercially av n area and d d to heal op Microstructu cts limits th ation problem r the develop recent decad buted to this eation and de de the materi quid to a solid derable period eratures, beca ith each other solid bridges last stage of ates either thr ors [5]. The g de the alloy d metal as it cha ot tearin y) u sand moul A dog-bon nd Si content tearing beh cation is co flows into th means of op d by bridged Several sam nd the micr vailable ima distribution pen fractures ure; Image an he production ms and, moreo pment of ho des to under phenomenon evelopment o ial, when the d state over a d of time dur ause it is liqu r, generating s are formed solidification rough the fu generation of during solidif anges from a ng of ld castings w e pattern wa ts were used aviour of th onsidered a he hot tear a ptical and sca d grain boun mples were al rographs fro age analysis of the eutec s caused by nalysis. n and perfo over, it has b ot tears durin rstand the pr n from both of macroscopi metal has no a certain temp ring casting. I uid with some a sort of ske between neig n in the mush ully liquid film f hot tears is p fication and a liquid to a s was prelimin as employed d. The effect he castings w very impor areas and cov anning elect ndaries and lso drawn fr om the opt software. T ctic phase w hot tearing ormance of been known f ng solidificat rincipal varia a theoretical ic fissures du ot yet comple perature inter In this semi-s e suspended s eleton [1]. Ab ghbouring gr hy state, while m or through principally du also related to solid, creating nary d for ts of were tant vers tron the rom tical The were for cast for a tion, ables and uring etely rval; solid solid bove rains e the h the ue to o the g an http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it mailto:mattia.merlin@unife.it inte of enr phy in shr eut It com Sev crit of acc crit this for sol Dif pro mo use hav wh al. sec [20 of b Th pou me bee ins sign elec ana dis cor a c MA Al fro ma at 7 cas Th cho 18 T ernal state of the mould. richments at ysical (fusion the last stage rinkage comp tectic in Al-C is very diffic mplexity of b veral authors tical paramete deformation cumulation in tical paramete s approach. rmulated a cri lid skeleton, w fferent exper oduce interna ould test” is t es a simple eq ve many varia here the equip [19] for the ction. The tes 0,21] and is th bars of differ he aim of this uring temper eans of the sa en used in or pection has b nificative zon ctron micros alysis softwar tribution of rrelation betw omplete crac ATERIALS AN lloys and castin he comm copper alloys ar om Alloy B fo ade based on 780 ± 5°C an sting, the melt he two differe osen; for each castings. T f stresses and Moreover, t both macros n point) and c es of solidific pensation by u alloys incre cult to perfo both the mec have tried to ers. For exam of a semi-sol n which the m er is not the s Clyne and D iterion based which is depe rimental tests al stresses in the most freq quipment and ations with re pment is desig study of alum st used for th he one carried rent length pr research is a ratures on th and mould ca rder to verify been perform nes of the c scopy (SEM) re have been the eutectic p ween the micr k caused by t AND EXPERIM ng system mercial EN A and silicon to re reported in for an increas its low castab nd the chemi t was accurat ent pouring te h alloy and ea strains, and, there is the scopic and m chemical (corr cation is very liquid feedin eases as the co orm a mathe chanical beha o understand mple, Novikov lid body at low most importan strain but the Davies paid d on afterfeed ndent on the s have been the casting quently used t d experiment egard to the gned to creat minium alloys he study of c d out by Rose roduced from a preliminary he hot tearing asting techniq y its ability to med on the cas astings for m . The micro statistically p phase. Finally rostructure an the hot tearin MENTAL PR AB-21100 all o the master n Tab. 1. Allo se in silicon c bility and hot cal compositi ely degassed i emperatures ach pouring t M. Me secondly, the tendency of microscopic le rosion resista y important, ng and the po oncentration ematical mod aviour of the the possible v and Novik w strain rates nt factor is th e strain rate, w more attenti ding (RDG cr permeability developed f by restricting to compare t ting [13-17]. V geometry of te an abrupt s s, involved th opper alloys enberg et al. [ m one single p study on the g behaviour o que. The Cou o also predict stings to dete metallographi graphs acqui processed to y, all data ha nd the tenden g phenomeno ROCEDURE loy (Alloy A) alloy, have b oy B differs f content from tearing susce ion has been in order to gu of 760°C and temperature, erlin, Frattura ed ere is the pre f alloying el evels [6]. Seg ance) behavio because a g ossibility of of copper inc del that can semi-solid p causes of ho [8,9] reported s, while Pellin e total strain with Prokhoro on to the ti riterion) that y of the mush for assessing g the free co the hot tearin Various other the mould. W section chang he realisation that was per [22], who des pouring. e effect of dif of the EN A uture-Edward t the hot tear ect surface cra c analysis, ca ired by optic obtain a qua ave been coll ncy of the san on. and two oth been selected from Alloy A m 0.2wt.% to eptibility. The analysed by uarantee high d 700°C, con three experim d Integrità Struttu esence of diff lements and gregations de our of the allo greater amoun crack healing creases [7]. reproduce t phase and the t tearing and d that the grai ni [10] suggest in the hot sp ov [1,11] bein ime spent in considered b hy zone. hot tearing ontraction of ng tendency o r tests refer t Wang et al. [1 ge in the cast of a casting rformed by C signed a moul fferent additio AB-21100 allo ds pattern, w ring behaviou acks and then arried out by cal microscop antitative eva lected and pl nd mould cas her variants (A for this inve A for a coppe 0.9wt.%. Th e metal has be means of op h molten quali ntrolled by m mental casting urale, 14 (2010) ferent solidific impurities t etermine a no oy. The amou nt of eutectic g. It has been the hot tearin e liquid flow have propos in boundary s ted a hot tear ot region. Som ng the first to n the mushy both the fluid susceptibility the alloy du of aluminium to the so-calle 18] developed ting, while the with six fan- Couture and E ld for the rea ons of coppe oy. Several ca well-suited for ur of alumini n several spec y optical mic py and previ aluation of th otted in orde stings, realised Alloy B and estigation; the er content of e choice of E een melted in tical emission ity. means of K-ty gs have been ) 64-74; DOI: 10 cation rates in to segregate, on-homogene unt of eutecti c increases th n shown that ng phenome in the interd sed models ba sliding is the ring theory ba me authors su o propose a cr state [12]. R d flow and de y, with the a uring solidific alloys becau ed “dog bon d a test for m e test propos -shaped bars Edwards is o alisation of ca er and silicon astings have r copper alloy ium alloys. A cimens have b croscopy (OM iously elabor he percentage er to underst d with the ex Alloy C), ob e average com f 6wt.%, whil EN AB-2110 n an electric in n spectroscop ype thermoco realised for a 0.3221/IGF-ESIS. n different zo thus produ eous mechan ic liquid avail he probability t the quantity enon due to dendritic regi ased on diffe main mechan ased on the st uggested that riterion based Rappaz et al. eformation of aim to artific cation. The “ use this techni e tests” and magnesium al sed by Vojtec with a triang of greater inte astings compo n and of diffe been realised ys [20,21,23], A liquid penet been drawn f M) and scann rated with im e, mean area tand the poss amined alloys tained by add mpositions of le Alloy C dif 00 alloy has b nduction furn py (OES). Be ouples, have b a total numbe 14.07 65 ones ucing nical, lable y of y of the ons. erent nism train t the d on . [3] f the cially “ring ique they lloys ch et gular erest osed erent d by has trant from ning mage and sible s, to ding f the ffers been nace efore been er of http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it M. 66 Th dep pou of sol des tea tha No Aft ins the is a Merlin, Frattura Alloy A Alloy B Alloy C he sand moul picted in Fig. uring. Each b a local hot lidification. In signed with a aring susceptib at completely on-destructive a ter solidificat pected visual e spherical fee also depicted a ed Integrità Str Si A 0.181 B 0.179 C 0.825 Table 1: lds have been . 1. As it can bar has a sphe spot that g n order to ha specific thick bility is the le fails or becom Figure 1: W analysis of the tion and coo lly and by a liq eder. For exa in the same f Figure 2 rutturale, 14 (20 Fe 0.121 0.120 0.115 Average chem n manufactur n be noted, th erical riser (fe generates high ave the same kness accordi ength of the b mes seriously Wood model of castings oling, the cas quid penetran ample, a phot figure. 2: Photo of a c 010) 64-74; DOI Cu M 4.22 0.4 6.33 0.4 5.95 0.4 mical compositi red accordin he casting is eeder) on one h tensile str quantity of ing to the leng bar; the greate y damaged. the casting rea stings were e nt test. Attent o of one cast casting produce I: 10.3221/IGF-ES Mn Mg 46 <0.01 46 <0.01 45 <0.01 ions (wt.%) of g to the Cou composed of e side, which resses due to metal, each b gth of the bar er the tenden alised to evalua extracted from tion has been ting has been ed in Alloy B w SIS.14.07 Cr <0.01 <0.01 <0.01 the alloys stud uture-Edward f four bars o determines a o the contra bar is constra r itself. A use ncy of the allo ate the hot tear m the sand n paid to the m reported in F with a pouring Ni T <0.003 0.1 <0.003 0.2 <0.003 0.2 died in the pres ds design and f different le an abrupt sect ction of the ained at the e eful paramete oy to generate ring behaviour moulds; the most critical z Fig. 2; a zoom temperature o Ti Zn 191 0.07 221 0.069 224 0.069 sent work. d the wood engths produc tion change w e alloy along end by a flan r for the eval e hot tears, th of the alloys. cracks on a zone, that is t m of a compl of 760°C. Al bal. bal. bal. models used ced in one si with the prese g the bar du nge that has b luation of the he shorter the all the bars w the hot spot n letely cracked d are ingle ence uring been e hot e bar were near d bar http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it Fiv ord cla cas num ma gre non Mi Th pos ve categories der to identif ssification of sting (1, 2, 3), mber of the b acroscopical o een. In Fig. 3, n-destructive [no c icrostructural a he non-destru ssible to the h Alloy A Alloy B Alloy C of hot tear se fy each single f the bars con , the second bar in ascend observations , there is a ph liquid penetr crack (------), lig analysis and fr uctive conside hot tear locati A B C everity have b e bar and to r nsists of a lett specifying the ding order fro of the casting hoto clearly sh rant testing m Table 2: Resu ght crack (/\/ fractography erations have tion or to the A.1.1 A.1.2 A.2.1 A.2.2 A.3.1 A.3.2 B.1.1 B.1.2 B.2.1 B.2.2 B.3.1 B.3.2 C.1.1 C.1.2 C.2.1 C.2.2 C.3.1 C.3.2 M. Me been consider refer it to th ter (A, B, C), e pouring tem om the longe gs has been s howing the de method. ults obtained fr \), crack (/\/\ e been usefu initiation of h bar n°1 (lon x x ------ x x x x x x x x x /\/\/\/\/ x /\/\/\/\/ /\/\/\/\/ /\/\/\/\/ /\/\/\/\/ erlin, Frattura ed red: no crack e specific cas which refers mperature (1 st to the shor summarised in etection of th rom visual and \/\/\), severe ul in the selec hot tears. Sam ngest) /\/ /\/ /\/\ / /\/\ /\/ /\/\ / /\/\ /\/ /\/\ d Integrità Struttu , light crack, sting a specia to the alloy, = 700°C and rtest (1, 2, 3, n Tab. 2; the he discontinui d liquid penetra e crack (/\/\/ ction of the mples, taken a bar n°2 x x \/\/\/\/\ x x x x x x \/\/\/\/\ x x \/\/\/\ /\/\ \/\/\/\/\ \/\/\/\ \/\/\/\/\ /\/\ urale, 14 (2010) crack, severe al nomenclatu and three nu d 2 = 760°C) 4). All the in completely c ity relating to ant inspections \/\/\/\) and representativ along the axia bar n°3 x x x x x /\/\/\/\/ /\/\/\/\/ /\/\/\/\/ x /\/\/\/\/ /\/\/\/\/ /\/\/\/\/ /\/\ /\/\/\/ ------ /\/\ /\/\/\/ /\/\ ) 64-74; DOI: 10 crack and co ure has been umbers: the fi and the third nformation ob cracked bars a o a hot spot, p s complete crac ve samples dr al and the rad 3 bar n /\/\ /\ /\ /\/\ /\/\ /\/\ /\ /\/\ /\/\ /\/\ /\ /\ 0.3221/IGF-ESIS. omplete crack considered. irst indicating d referring to btained from are underline performed by ck (x)]. rawn as clos dial cross sect °4 (shortest) \/\/\/\/\ \/\/\/\ x \/\/\/\ x /\/\ /\/\ \/\/\/\ /\/\ /\/\ /\/\ /\/\ ------ ------ ------ ------ ------ ------ 14.07 67 k. In The g the o the m the ed in y the e as tions http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it M. 68 of (OM and Th pha spe Ima Im Dif bee dif cen con cra For dra rev RE Mi wa ana ide Fe- tem Ho ava hot be T Merlin, Frattura the bars, hav M). The micr d the presenc he investigatio ase in the pr ectroscopy (E age analysis mage-Pro Plus fferent micro en calculated, fferent lengths ntroid of each ncentration o acked bars has r performing awn from all vealing its mic ESULTS icrostructural a he typic of α-Al from ca s found. In F alysis second entified in the -Si secondary mperatures [2 ot tears are pr ailable, the hig t tears are rep noted, the de T a ed Integrità Str ve been prep rostructure h ce of secondar on of the tea rocess, has b EDS). Fig s software ha ostructural pa , taking into a s of the bars. h portion of t of stresses. T s been evalua g this kind of the bars in crostructure h analysis cal microstruc with the sec astings poured Fig. 4 the mic dary phases, i e samples. Th y phases, w 5]. resent in all th gher the prob ported that ar evelopment o rutturale, 14 (20 pared for the as been exam ry phases and ar surface fra been carried gure 3: Photo o as been used arameters, suc account the c The minimu the eutectic p The correlatio ated. f analysis, all the hot spo have been acq cture of the s ondary phase d at different crostructure o in particular he presence o which in gen he analysed s bability of shr re a) partially of cracks durin 010) 64-74; DOI metallograph mined and imp d fractured br actography, in out by scan of a hot tear re d to carry ou ch as quantity chemical com um-radius is a phase and its p on between the 18 casti ots near the s quired by opt and cast Al-C e CuAl2. Whe temperature of the eutecti Fe-rich inter of a greater am neral contribu amples even rinkage comp y or b) totally ng solidificati I: 10.3221/IGF-ES hic inspection portant infor ridges involve n particular w nning electron evealed by the ut a prelimin y, mean area mpositions of an important p perimeter, an the calculated ings have bee spherical feed tical microsco Cu alloys con en comparing s, no evidenc ic phase can rmetallics like mount of sili utes to a de though it has pensation by l y healed by th ion follows in SIS.14.07 n performed rmation conce ed in the hot with the aim n microscopy liquid penetran nary image a and mean m the examined parameter rep nd it can there d microstruc en taken into der. From ea ope and subse nsists of the p g the microst ce of grain gr be noted; acc e Al7Cu2Fe w icon in Alloy ecrease in m s been observ liquid feeding he eutectic liq nterdendritic by the Leica erning fractu tearing proce of understan y (SEM) and nt testing meth analysis study minimum-radi d alloys, the p porting the m efore be cons ctural parame o account and ach sample, t equently elabo primary α-Al p tructures of c rowth due to cording to lit with the typi C has determ mechanical p ved that the g g. In the micr quid during th and intergran a MEF4M op re paths, crac ess have been nding the rol d by energy hod. y with a stat ius of the eut pouring temp minimum dista sidered as rela eters and the d three speci three signific orated by the phase and an corresponding a higher pou terature [24] a ical needle sh mined the pre properties, es greater the am rographs of F he last solidifi nular paths in ptical microsc ck healing eff n obtained. le of the eute dispersive X tistical appro tectic phase h peratures and ance between ated to a poss e cracked or imens have b cant microgra software. n eutectic mix g samples dr uring tempera and also by E hape, have b ecipitation of specially at h mount of eute Fig. 5 example fication. As it side the mate cope fects ectic X-ray oach. have d the n the sible un- been aphs xture rawn ature EDS been f Al- high ectic es of can erial. http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it If t film hot adj the sign All Figure 4: Opti the amount o m, the grains t tears at the acent dendrit e fraction of s nificative imp loy B. ical micrograph Figure 5 of eutectic mix try to coales e last stage of te arms can b solid bridges provement in Fig Fr hs showing the (a) 5: Hot tears in xture is small sce by bridgin f solidificatio be identified. on the hot te n the hot tear (a) gure 6: Solid b actured and no M. Me e microstructur a sample draw l and is not en ng; the presen on. In the opt It is well-kno ear surfaces [ ring behaviou bridges in samp o-fractured bri erlin, Frattura ed re of the eutec wn in C.2.1.3: a) nough to cov nce of fractu tical microgra own that the 7]. Moreover ur with the m ples drawn from dges are depic d Integrità Struttu ctic mixture an ) partially heale ver the grain b ured bridges i aphs of Fig. decrease of c r, the microst moderate add m a) A.3.1.1 an ted in red and urale, 14 (2010) d the presence (b) ed and b) total boundaries an indicates the 6 a) and b) copper conce tructural analy dition of silico (b) nd b) A.3.2.1 b blue, respectiv ) 64-74; DOI: 10 e of secondary lly healed. nd to form a c propagation several solid entration caus ysis showed t on in Alloy C bars. vely. 0.3221/IGF-ESIS. phase particles continuous liq of interdend bridges betw ses an increas that there was C with respec 14.07 69 s. quid dritic ween se in s no ct to http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it M. 70 SE Sca SE frac film of Pre in F Fe- inte Sev wit less are It i beh wo res geo Merlin, Frattura EM analysis anning electro EM analysis o cture surface m in the last s Fig. 8. Figure ecipitates of s Fig. 9 for a s -Si platelet. T erdendritic cr veral solid br th Alloy A. T s alloyed mat e reported in F is important t haviour of bi ork, no signs earch, Alloy ometrical feat a ed Integrità Str on microscop of a hot tear of alloys con stages of solid e 7: Hot tear at sample draw secondary ph ample drawn The presence racks. ridges have b The fraction o terials [26]. M Fig. 10 and F to compare th illets cast fro of hot tears A that con tures of the C rutturale, 14 (20 py has been u reveals its ty ntaining signi dification, wh t low magnifica wn from A.2.1.1 ases have bee n from the ho of these seco Figure 9: SEM been found o of bridged gra Micrographs o Fig. 11, respec he results her m Al-Cu allo in alloys that tains 4.8wt.% Couture-Edw 010) 64-74; DOI used to invest ypical intercry ificant amoun hich covers a ation in a 1. en found on ot spot in the ond phase pl M micrograph n the hot tea ain boundarie of fractured b ctively. e obtained wi oys with diffe t contained m % copper is wards pattern I: 10.3221/IGF-ES tigate the hot ystalline path nts of copper at least part of Fig the fracture s e C.3.2.1 bar. latelets can co of a Al-Fe-Si p ars surfaces, es depends m bridges observ with those sho erent copper more than 4w very suscept used to test SIS.14.07 tear surface h, which is th r is typically s f the surface; gure 8: Fractu surfaces of th EDS analysis ontribute to platelet with E in particular mostly on the ved in sample own by Suyitn concentratio wt.% copper h tible to hot the hot teari fractography he result of i smooth due t ; an example ure surface of a he samples an s has revealed limit the flow EDS spectrum. in samples d alloying cont es taken from no et al. in [27 ons and prod have been fo tearing and ng behaviour y. As can be s interdendritic to the presen is depicted in a sample drawn nalysed. An e d the presenc w of the eute drawn from c tent and tend m the A.2.2.3 7], who studie duced by DC ound. On the this is prob r. For higher een in Fig. 7, c separation. nce of an eute n the microgr n from C.1.2.1 example is sho ce of a brittle ectic liquid in castings obtai s to be greate and A.3.1.1 ed the hot tea casting. In t contrary, in bably due to copper cont , the The ectic raph . own e Al- n the ined er in bars aring their this the tents http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it the hot Ima As stu mic pro dis dat com frac cas pou eut Co 760 in t dev com can am len effe e effect of the t tears. Figure 10: age analysis mentioned i udy possible c crographs ha ocessed by m tribution in t ta have been mposition of ctures; the in stings that is uring temper tectic phase, i omparing the 0°C, the crack the diagram o viation of 4.7 mprehensive n be seen fro mount of eutec ngth of the ba fect in the last Figure 12: E e greater eute Fractured soli in Materials an correlations b ave been obta means of ima terms of mean n collected a f the alloys. T ncrease in bot to the decrea rature: at an independently results obtain ked bars are of Fig. 12. Th 73%, while in of data obtai om the diagra ctic phase tha ars seems to t stages of sol Eutectic percen ctic liquid ava id bridges in sa nd experimenta between mic ained by opt age analysis s n minimum-r and correlate The correlatio th the percent ase of the num equal eutecti y of the lengt ned from the characterised he mean valu the un-crack ined from sam am, among t an the longes play an impo lidification. ntage in the sa M. Me ailable in the ample A.2.2.3. al procedure: Im crostructural p tical microsco software. Qu radius of the ed with the ons suggest t tage and the c mber of crac ic percentage th of the bars e samples dra d by a smaller ue of the perc ked bars it is mples drawn the un-cracke st ones (n°1 a ortant role in mples drawn f erlin, Frattura ed last stages of mage analysis, I parameters a opy in the ho uantitative inf eutectic phas pouring tem the importanc coarseness of cked bars. Mo e, the casting and the alloy awn from cra r percentage o centage of the 14.54% with n from all the ed bars the s and n°2). Acc the eutectic from cracked a d Integrità Struttu f solidification Figure 11: Fr Image-Pro Pl and the hot t ot spot near formation co se has been c mperature, th ce of the cap f the eutectic oreover, an in gs poured at y. acked and un of eutectic ph e eutectic in t a standard d castings; this shortest bars cordingly, the liquid flow a and un-cracked urale, 14 (2010) n strongly co ractured solid b lus software tearing behav the spherica oncerning the carried out. U e cracked an pability of the phase contri nteresting res the highest t -cracked bars hase than the the cracked b eviation of 5 s justifies the (n°3 and n° e geometrical and, as a cons d bars of all the ) 64-74; DOI: 10 ntributes to t bridges in sam has been use viour of the al feeder of a e percentage, Using a statist nd un-cracke e eutectic liqu ibutes to the sult concerns temperature s of all the ca e un-cracked o bars is 11.65% .4%. The resu e high standar °4) are charac effect related sequence, in t e castings pour 0.3221/IGF-ESIS. the healing of mple A.3.1.1. ed to prelimin castings. Sev all bars and t , mean area tical approach ed bars and uid to heal o soundness of the effect of present a co astings poure ones, as depi % with a stand ult is general rd deviations cterised by m d to the diffe the crack hea red at 760°C. 14.07 71 f the nary veral then and h, all the open f the f the oarse ed at cted dard and s. As more erent aling http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it M. 72 Th of qua obt pou cra stat mic gre con neg the pro the Th par cou obt Merlin, Frattura he same correl each alloy; th antity of eute tained from A uring temper acked bars ca tistical proce crostructural eat influence i nflicting cons gative effect d e interdendrit ocessing of d e lowest numb he mean minim rameter relate uld be a usefu tained in un-c a ed Integrità Str lation betwee his relation fo ectic phase a Alloy B and t rature and of aused by the ssing of the analysis expl in the hot tea sequences: a due to the pr tic zones. D data, from the ber of compl Figure 13 mum-radius o ed to the pos ful index for t cracked bars, Figure 14: rutturale, 14 (20 en the percen or Alloy A is available to h his is in good f the copper developmen micrographs lained in secti aring behavio positive effe recipitation o Despite the r e visual and t etely cracked 3: Correlation b of the eutectic ssible concent the evaluation it seems that Correlation be u 010) 64-74; DOI ntage and mea depicted in F heal the hot d agreement w content in t nt of hot tear of the samp ion Microstruc our of the exa ect due to th of Al-Fe-Si pl esults obtain the liquid pen bars. between percen c phase calcu tration of str n of the susc t there was no etween mean a un-cracked bars I: 10.3221/IGF-ES an area of the Fig. 13. As ca tears is both with the visua the alloy cont rs. No furthe ples drawn fr ctural analysis; amined alloy. he higher cas latelets that c ned by the m netrant inspec ntage and mea ulated for both resses in the m ceptibility to h o significative area and minim s for castings p SIS.14.07 e eutectic pha an be seen, if h greater and al and liquid p tribute to the er significant rom the casti it seems that Perhaps, the tability of th an contribute metallographi ctions (Tab. an area of the e h cracked and material; its lo hot tearing (F e correlation r mum radius of t poured at 760° ase has been f the pouring d coarser. Th penetrant insp e reduction o information ings produce t small silicon presence of he alloy than e to limit the ic analysis an 2) the casting eutectic phase i d un-cracked ower value in Fig. 14). Mor related to the the eutectic in °C. studied by se g temperature he same tren pections. The of the numb has been ob ed in Alloy C n additions (0 silicon in allo Alloy A and flow of the nd the subse gs realised in in Alloy A. bars has been n cracked bar reover, consid different len cracked and eparating the e is increased, nd has also b e increases of er of comple btained from C, confirming 0.7wt.%) have oy C has had d Alloy B, an eutectic liqui equent statis n Alloy C pre n considered rs suggests th dering the res ngth of the ba data , the been f the etely the g the e no two nd a id in stical sent as a hat it sults ars. http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it CO fo b - S co la - In eu - A h in - A d m p - F th h AC RE [1] [2] [3] [4] [5] [6] [7] [8] [9] [10 [11 [12 [13 [14 [15 [16 [17 B T ONCLUSION ased on EN AB - The C oundry alloys bars of differe everal solid f opper and th ast stages of s n the alloys w utectic phase A moderate in healing pheno n Alloy C pre A preliminary drawn from th microstructure phenomenon. Further studie he solidificati hot spots, will CKNOWLEDG he autho realisatio Dr. Gau EFERENCES D. G. Eskin J. Campbell M. Rappaz, M. Rappaz, Materials Pr A. B. Phillio D. G. Eskin Suyitno, D. I. Novikov, I. Novikov, 0] W. S. Pellin 1] N. N. Prokh 2] T. W. Clyne 3] H. Chadwic 4] W. Patterso 5] A. R. E. Sin 6] M. Drezet, Processes V 7] D. Warringt B T NS n the obtained B-21100 and o Couture-Edwa s thanks to th ent lengths. fractured brid herefore, amo solidification. with the high has been rev ncrease in the omenon; even esented the lo y statistical st he castings rel e and the t Obviously, t es are under c ion of the allo l be soon rela GEMENT or wishes to t on of the alu udenzio Preti S n, Suyitno, L. l, Casting: Th J. M. Drezet , I. Farup, J. rocessing, TM on, S. L. Cock n, Suyitno, J. G. Eskin, L. , Hot shortne , F. S. Novik, ni, Foundry, 8 horov, Russia e, G. J. Davie ck, Casting M on, S. Engler, nger, P. H. Jen M. Rappaz, VIII, San Dieg ton, D. G. M d results, the of its two foun ards test has he presence o dges have be ong the exami hest copper vealed by mea e contents of n though it se west number tudy has been lating to the h endency of to confirm the consideration oys. The calcu ted to the qu thank Fonder uminium casti and Dr. Enri Katgerman, he New Metal t, M. Gremau M. Drezet, MA (The Min kcroft, P. D. F. Mooney, L Katgerman, ess of non-fer Doklady Ak 80 (1952) 124. an Castings P es, J. British F Metal, 4(1) (19 Aluminium, nnings, J. Ins , In: Internat go (USA), (19 McCartney, Ca M. Me following con ndry variants proved to b of hot spots g een found on ined alloys, c content the ans of micros f silicon in th eems that silic r of cracked b n performed hot spots; it h Al-Cu sand ese results th to correlate ulation of a h antitative mic ria Scacchetti ings. Many th ico Santarato Progress in M llurgy of Cast ud, Metallurgic In: Proceedi nerals, Metals Lee, Material L. Katgerman Materials Sci rrous metals a ad Nauk SSS . Production, 2 Foundry, 74 (1 91) 43. 35 (1959) 124 titute of Meta tional Confer 998). ast Metals, 2(3 erlin, Frattura ed nclusions can s containing a be suitable for generated by n the hot tear haracterised b crack healing structural anal he alloy did n con did not a bars. by means o has been very mould cast e analysis nee the obtained hot tearing ind crostructural i Leghe Legge hanks are also for their exp Materials Scie t Metals, Butt cal and Mater ings of the M & Materials S ls Science and n, Metallurgica ence and Eng and alloys, M R, Ser Fiz, 7 (1962) 172. 1981) 65. 4. als, 73 (1947) rence Model 3) (1989) 134 d Integrità Struttu n be drawn as additions of co r the study o a critical sect r surfaces, es by the lowest g effect due lysis of severa not significan affect the dist of image analy y useful to un tings to a c eds to be perf information dicator, based parameters p ere srl of San o due to Dr. perimental con nce, 49 (2004 terworth-Hein rials Transact Merton C. Fl Society) (200 d Engineering al and Materi gineering A, 4 oscow, Nauk (1963) 1153. 197. ling of Castin . urale, 14 (2010) s regards the opper and sil of the hot tea tion change b specially in A t amount of e to the distrib al samples dra ntly contribut tribution of th ysis software nderstand pos complete fail formed on a g with the stre d on the surfa presented in th n Felice sul Pa Lorenzo Pive ntribution to 4) 629. nemann 2nd tion A, 30, (19 lemings Symp 1). g A, 491 (200 ials Transactio 420 (2006) 1. ka, (1966) 299 ng, Welding ) 64-74; DOI: 10 hot tearing b licon: aring behavio between sphe Alloy A conta eutectic liquid bution and c awn from the te to an incre he eutectic ph e on the vari ssible correlati lure due to greater numb ss state of th ace fraction o his paper. anaro (Moden etti, Dr. Ales this research edition, Oxfo 999), 449-455 posium on S 08), 237. ons A, 35A (2 9. and Advanc 0.3221/IGF-ESIS. behaviour of a our of alumin erical feeders aining 4.8wt.% d available in coarseness of e hot spots. ease of the c hase, the cast ous microgra tions between the hot tea ber of samples he material du of hot tears in na - Italy) for ssandro Caval h. ord (2003). 5. Solidification 2004) 1325. ced Solidifica 14.07 73 alloy nium and % in n the f the rack tings aphs n the aring s. uring n the r the llini, and ation http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it M. 74 [18 [19 [20 [21 [22 [23 [24 [25 [26 [27 Merlin, Frattura 8] Y. Wang, B 9] D. Vojtech, 0] A. Couture, 1] A. Couture, 2] R. A. Rosen 3] M. Merlin, G 4] E. Di Russo 5] N. Han, X. 6] Y. Ju, L. Ar 7] Suyitno, D. a ed Integrità Str B. Sun, Q. Wa , J. Serak, O. , J. O. Edwar , J. O. Edwar nberg, M. C. F G. L. Garagn o, The atlas o F. Bian, et al rnberg, Int. J. G. Eskin, V. rutturale, 14 (20 ang, Y. Zhu, W Eckert et al., rds, Trans. AF rds, AFS Cast Flemings, H. nani, G. Ventu of microstruct l., Acta Metall Cast Metals . I. Savran, L. 010) 64-74; DOI W. Ding, Mat Materials Sci FS., 74 (1966) t Metals Resea F. Taylor, Tr uri Pagani Ce tures of alumi lurgica Sinica Research, 16 . Katgerman, I: 10.3221/IGF-ES terials Letters ience and Tec ) 709. arch Journal, rans. AFS., 68 esa, La Metall inium casting a (Engl. Lett.) (2003) 522. Metallurgical SIS.14.07 s, 53(1) (2002) chnology, 19 (1967) 57. 8 (1960) 518. urgia Italiana g alloys, Edim , 19(6) (2006) l and Materia ) 35. (2003) 757. a, Honegger, M met Ed., Bresc ) 405. als Transaction Milano, 7/8 ( cia (1993). n A, 35A (20 (2007) 35. 04) 3551. http://dx.medra.org/10.3221/IGF-ESIS.14.07&auth=true http://www.gruppofrattura.it << /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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