Issue 14

M.

Merlin, Frattura

ed Integrità Str

utturale, 14 (20

10) 64-74; DOI

: 10.3221/IGF-ES

IS.14.07

of (OM and Th pha spe

the bars, hav ). The micr the presenc e investigatio se in the pr ctroscopy (E

e been prep ostructure h e of secondar n of the tea ocess, has b DS).

ared for the as been exam y phases and r surface fra een carried

metallograph ined and imp fractured br ctography, in out by scan

ic inspection ortant infor idges involve particular w ning electron

performed mation conce d in the hot ith the aim microscopy

by the Leica rning fractu tearing proce of understan (SEM) and

MEF4M op re paths, crac ss have been ding the rol by energy

tical microsc k healing eff obtained. e of the eute dispersive X

ope ects ctic -ray

Fig

ure 3 : Photo o

f a hot tear re

vealed by the

liquid penetran

t testing meth

od.

Ima Im Dif bee dif cen con cra For dra rev

ge analysis age-Pro Plus ferent micro n calculated, ferent lengths troid of each centration o cked bars has performing wn from all ealing its mic crostructural a he typic of α-Al from ca s found. In F lysis second ntified in the Si secondary peratures [2 t tears are pr ilable, the hig tears are rep noted, the de SULTS

software ha structural pa taking into a of the bars. portion of t f stresses. T been evalua this kind of the bars in rostructure h nalysis al microstruc with the sec stings poured ig. 4 the mic ary phases, i samples. Th phases, w 5]. esent in all th her the prob orted that ar velopment o

s been used rameters, suc ccount the c The minimu he eutectic p he correlatio ted. analysis, all the hot spo ave been acq

to carry ou h as quantity hemical com m-radius is a hase and its p n between the 18 casti ts near the s uired by opt

t a prelimin , mean area positions of n important p erimeter, an the calculated ngs have bee pherical feed ical microsco u alloys con n comparing s, no evidenc c phase can metallics like ount of sili tes to a de though it has ensation by l healed by th on follows in

ary image a and mean m the examined arameter rep d it can there microstruc n taken into er. From ea pe and subse

nalysis study inimum-radi alloys, the p orting the m fore be cons tural parame account and ch sample, t quently elabo

with a stat us of the eut ouring temp inimum dista idered as rela ters and the three speci hree signific rated by the

istical appro ectic phase h eratures and nce between ted to a poss cracked or mens have b ant microgra software.

ach. ave the the ible un een phs

R E

Mi Ho ava hot be T wa ana ide Fe tem

ture of the s ondary phase at different rostructure o n particular e presence o hich in gen e analysed s ability of shr e a) partially f cracks durin

and cast Al-C CuAl 2 . Whe temperature f the eutecti Fe-rich inter f a greater am eral contribu amples even inkage comp or b) totally g solidificati

sists of the p the microst e of grain gr be noted; acc Al 7 Cu 2 Fe w con in Alloy crease in m been observ iquid feeding e eutectic liq terdendritic

rimary α-Al p ructures of c owth due to ording to lit ith the typi C has determ echanical p ed that the g . In the micr uid during th and intergran

hase and an orresponding a higher pou erature [24] a cal needle sh ined the pre roperties, es reater the am ographs of F e last solidifi ular paths in

eutectic mix samples dr ring tempera nd also by E ape, have b cipitation of pecially at h ount of eute ig. 5 example cation. As it side the mate

ture awn ture DS een Al igh ctic s of can rial.

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