effect of zno nanoparticles on thermal, microsture and tensile properties of ssc505 lead free solder...
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Influence of ZnO nanoparticles addition on thermal, microstructureand tensile properties of
Sn-5.0 wt%Sb-0.5 wt%Cu (SSC505!ead-free solder allo"
A. N. Fouda a , El Shazly M. Duraia a,, E. A. Eid b
(a) Physics department, Faculty o Science, Suez!"anal #ni$ersity, %&' smailia, E*ypt (b) +asic Science Department, i*her -echnolo*ical nstitute, & th o /amadan "ity, E*ypt.
#bstractFor de$elopment o a lead! ree composite solder or ad$ance electronics components
connections, a *roup o Sn!'Sb! .'"u (SS"' ') and Sn!'Sb! .'"u! .'0n1 (SS"!
.'0n1) lead ree solder alloys ha$e been in$esti*ated. /esults o di erential scannin*
calorimetry appear the addition o .' 2t.3 0n1 nano particles satis y insi*ni icantincreasin* in meltin* temperature 4 - m 5 .67 o"8. Field emission scannin* electronic
microscope (EF!SEM) ima*es o SS"! .'0n1 composite solder re$ealed a uni orm
distribution and re inement !Sn *rain sizes, "u 9 Sn ' and SnSb intermetallic compounds
( M"s). Presence 0n1 nano!po2der in solder matri: enhanced their yield stress y
( . 3;S) and ultimate tensile stren*th #-S , but their ductility reduced due to embed the
nanoparticles in *rain boundaries. 0n1 pinnin* e ect obstructed the motion o
dislocations and has hi*hly acti$e sur ace area that supports the stron* adsorption e ect
o "u atoms.
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Introduction
the public a2areness o
en$ironmental issues and increasin* ?no2led*e o hazards to:ic materials has been
2ea?enin* up lately. /ecently, the strict le*islations put to eliminate the use o lead!basedsolders because o the healthy concerns o$er the to:icity o lead (Pb). n last decade *reat
e orts are pro$ided an ine$itable moti$ation orce or de$elopment o lead! ree solder
alloys. Further, the modern technolo*ical de$elopment in the electronic pac?a*in*
industry met challen*es to2ards miniaturization and unctional density enhancement.
-hese re@uire much smaller solder oints and Bne pitch interconnections or
microelectronic pac?a*in* in electronic de$ices. For e:ample, portable electronic
de$ices, such as portable computers and mobile phones, ha$e become thinner and smaller
2ith more complicated unctions. Mechanical beha$iors o solder alloys are acti$e and
play an important role because o their hi*h homolo*ous temperatures (-C- m .').
Moreo$er, the electronic assemblies are made up rom materials 2ith a 2ide ran*e o
thermal e:pansion coe icients ("-E). Durin* the s2itchin* on and o electronic
de$ices, the chips in electronic de$ices heat up and cool do2n, thus su erin* rom lo2
cycle thermo!mechanical ati*ue (-MF) due to stresses that de$elop as a result o
mismatch bet2een the solder, the substrate and the components 48. -hese -MF cycles
cause plastic strainin* o solder. ence, the de ormation imposed on the solder oints
durin* their operation is time dependent in the metallur*ical sense.
For instance, because o the creep o solder, time!dependent and *radual
misali*nment bet2een a solid state laser chip and a spherical lens on a Bbre in li*ht *uide
ocean cables 2ill reduce the transmission intensity or e$en cause complete loss o the
li*ht 2a$e communication si*nals in the cables 468. n de ense applications, the
mechanical $ibration o tan?s, airoplanes or missiles 2ill create hi*h re@uency
$ibrational ati*ue conditions or solder oints in the attached electronic components andlead these 2eapons to ail. ence, hi*hly creep and ati*ue resistant lead! ree solders
must be de$eloped to sol$e these problems.
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-he solders containin* ' percent antimony or sil$er are pre erred or electrical
e@uipment because o their *ood electrical conducti$ity. -he tin! and lead!based babbitts
(2hite metals) ha$e the lon*est history 4 8 but they are not ade@uate or most applications
in automoti$e en*ines. -he correlation o the alloys= structure 2ith mechanical and
electrical properties o metallic bearin* materials has been a topic o interest or se$eral
years attractin* the attention o many in$esti*ators 4 78. Most o the studies ha$e been
ocused either on mechanical or electrical properties or on microstructure eatures.
Since many Sn!rich solder alloys, includin* Sn!'3Sb and Sn! .'3A*,
*enerally ha$e a hi*her meltin* point than that o Pb!Sn eutectic, they may not be
suitable as replacement or Pb!Sn eutectic. o2e$er, they can be candidates or thereplacement o the Pb!rich solder alloys, such as Pb! 3Sn, Pb!& 3Sn, and Pb!'3Sn,
2hich ha$e a li@uidus temperature hi*her than 6 o" -he Pb!rich solders ha$e been
e:tensi$ely used or lip chip connection, and solder ball connection, 2here either Si
chips or modules are mounted onto a ceramic substrate.
Se$eral electronic applications o Sn!'3 Sb solder ha$e been reported,
includin* hermetic sealband o multichip modules, bondin* a semiconductor de$ice
onto a substrate, G and oinin* o C1 pins to multilayer ceramic substrates. s n the
oinin* C1 pins, Au! 3Sn braze alloy 2as replaced by Sn!'3Sb solder, thus
realizin* se$eral ad$anta*es, such as lo2erin* the oinin* temperature by about ' H
and reducin* the stress induced due to the oinin* process. n addition, Sn!'3Sb
solder oints o er *ood stren*th and creep properties or the application. n another
application, Sn!'3Sb solder 2as used as corrosion protection coatin* to a steel
plate, as 2ell as an electrically conducti$e area 2hich could be used or subse@uent
*roundin*. A small addition o Sb to the Pb!Sn eutectic solder has been reco*nized or a
lon* time to impart se$eral bene icial e ects, such as pre$ention o tin pest, H
stren*th impro$ements, and creep resistance. Antimony addition to the pure Sn
metal *enerally con irms the same bene icial e ects obser$ed 2ith the Pb!Sn eutectic
solder. n -able , a si*ni icant increase in shear stren*th is noted or solder
oints made o Sn!'3 Sb solder in comparison 2ith those made o the pure Sn.
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-able I also sho2s a better thermal ati*ue li e o P- oints made 2ith Sn!'3Sb
than those o pure Sn. o2e$er, one dra2bac? is reco*nized 2ith Sn!'3Sb solder
in terms o solderability as sho2n in -able I. -he solderability o Sn!'3Sb, as
measured by the percent spread o a 2ettin* area, is lo2er than that o the Pb!Sn
eutectic, and it is also reduced by addin* Sb to pure Sn. -he addition o Sb into pure Sn
can be harm ul to the mechanical properties 2hen the Sb le$el approaches the
solubility limit in Sn, 2hich is about & 3 by 2ei*ht at ' H ' -his is attributed to an
e:cessi$e ormation o the cubic intermetallic phase, SnSb 9 #nli?e the Pb!Sn system,
the Sn!Sb system e:hibits a peritectic reaction 2hereby the Sn!rich primary solid
solution is ormed at ' H -he microstructure o the Sn! '3Sb solder oints is,
there ore, e:pected to be hi*hly dependent upon the solderin* process and the thermal
e:posure a ter2ard.
1 the lead! ree solders de$eloped, only the hi*h meltin* point Sn 6 Au alloy
can 2ithstand hi*h temperature ser$ice conditions. o2e$er, this alloy cannot be utilized
in a 2ide ran*e o manu acturin* situations due to its cost and the de*radation o the
properties o electronic components by hi*h temperature solderin*.
-o sol$e this problem, e orts ha$e been made to de$elop solders 2ith a lo2
meltin* point and hi*h creep resistance. ence, much research has been carried out on
the addition o a third element (+i, Al, "u or A*) into the Sn Sb peritectic solder alloys
to impro$e the 2ettin* characteristics and creep resistance4:8. Moreo$er, another
potentially $iable and economically a ordable approach is the addition o discrete
secondary particles to the solder matri: so as to orm a composite solder 4:8.
Published literature sho2s that, to obtain the reBnement and stable microstructure
o a solder alloy an addition o discrete secondary particles 2as mi:ed to a solder matri:
to orm a composite solder. -hese studies indicate that the addition o secondary particles
to a lead! ree solder matri:, and thereby the ormation o a dispersion!stren*thened
solder, is a $iable approach to preparin* lead! ree solder 2ith enhanced mechanical
properties. -he rein orcement particles used in the composite materials usually included
micro!Cnano!size metallic, intermetallic, or o:ide particles. Ma$oori et al. 4J8 de$eloped
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a Pb! GSn based solder 2ith & nm Al 1 and ' nm -i1 rein orcement particles and
reported si*ni icant impro$ements in creep resistance and mechanical properties.
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addition, the tensile properties o the SS"' ' and SS"!0n1 solder is measured to
e:plore the potential stren*thenin* e ect o 0n1 nanoparticles on the prepared solder.
$- &perimental procedures
A lead! ree solder, Sn '. 2t3Sb .' 2t 3"u (SS"' ') solder alloy, is preparedrom Sn, Sb and "u in*ots o 77.77 3 purity. SS"' ' lead ree composite solder 2as
prepared by mechanically mi:in* .' 2t3 o nano!sized 0n1 particles into the prepared
con$entional SS"' ' lead ree solder 2ith subse@uent remeltin* in a $acuum urnace at
9 or h. -he in*ots 2ere used or our times in order to obtain a homo*eneous
composition, then ollo2ed by castin* into a stainless steel mold ollo2ed by slo2ly
cooled to room temperature. -he t2o alloys in the orm o bars 2ere cold dra2n into a
.6 mm diameter 2ire. A part o each alloy 2as rolled into a sheet o .% mm or
microstructure in$esti*ations. Specimens 2ith a *au*e len*th o ' mm 2ere prepared
or tensile testin*. Prior to the tensile testin*, all specimens 2ere heat!treated at a
temperature o 7 or .' h and then slo2ly cooled to room temperature to stabilize
microstructure and remo$e the residual de ects produced durin* the cold dra2n process.
For metallo*raphic obser$ations, as!solidi ied specimens 2ere prepared initially
by mountin* in cold epo:y. -his 2as ollo2ed by an initial coarse *rind or remo$in* the
cuttin* layer and mechanically polished on pro*ressi$ely iner *rades o silicon carbide
impre*nated emery paper usin* copious amounts o 2ater as the lubricant. -he samples
2ere then ine polished usin* & m and m alumina po2der suspended in distilled 2ater
as the lubricant. Final polishin* to near mirror!li?e sur ace inish 2as achie$ed usin*
. m diamond paste suspended in distilled 2ater.
-he as!polished samples 2ere chemically etched in a solution o 6 3 *lycerin,
& 3 nitric acid and & 3 acetic acid or a e2 seconds. -he etched sur aces o the solder
samples 2ere obser$ed in an optical microscope 2ith the ob ecti$e o determinin* thesize and morpholo*y o the *rains, and presence, distribution, and morpholo*y o other
phases present in the microstructure. -he structure and morpholo*ies o the as!
prepared materials 2ere characterized by J!ray di raction (/i*a?u DCma:! J!ray
di ractometer 2ith "u radiation ( 5&.'%&G6), step size 5 . , & O O7 ),
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ield emission scannin* electron microscopy (FESEM, S#6 Series e@uipped 2ith
ener*y dispersi$e J!ray analysis (EDJ), &' ?I) and transmission electron
microscopy (-EM, itachi, EM! & , ?I), respecti$ely.
DS" measurements 2ere carried out under the protection o hi*h purity nitro*en*as atmosphere to a$oid any une:pected o:idation. -he applied thermal treatment
procedure in the calorimetric e:periment 2as as ollo2sK the specimen 2as irst heated
rom room temperature up to '% at a constant rate o & min Q&.
-ensile tests 2ere carried out by strainin* each specimen to racture. Stress strain
measurements 2ere per ormed at di erent strain rates ran*in* rom &.G:& !% to&:& ! s!&
at di erent testin* temperatures ran*in* rom 76 to G usin* a computerized tensile
testin* machine described else2here 4 8.
3- Results and Discussion:
'- )hermal properties *eltin+ eha ior
Fi*ure & e:hibits DS" thermo*rams o S""' ' and S""! .'0no solder alloy, a
ne*li*ible e ect or risin* the meltin* temperature 2as obser$ed bet2een them ( - m 5
.67 o"). o2e$er, the meltin* temperature o the SS"' ', and SS"! .'0n1 are G. 6,
6. Go" respecti$ely, these results ha$e *reat si*ni icance 2hen compared 2ith meltin*
temperature o Sn!'2t3Sb (- m 5 %9 o") 2hich is considered as baseline or hi*h
meltin* lead! ree solders.
ast" /an+e
-he most distinct common eatures o endothermic pea?s summarized in table &. -hey
are initiated at solidus temperature R- onset R (solid phase initiate to con$ert to a li@uid phase) and
ended at li@uidus temperature - endset (solid phase completely chan*ed to li@uid phase).
orth2hile, solidus temperature and li@uidus temperature are estimated by usin* intersection point bet2een the horizontal tan*ent o baseline and the tan*ent line or each side o
endothermic pea?, the di erence bet2een li@uidus (-
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process ( ). From table (&) it is seen that, the solidus and li@uidus temperatures o SS"' '
solder alloy are .%' o" and %G. o" respecti$ely, its pasty ran*e is (-
to estimate the pasty ran*e o SS"!0n1 (-
li@uidus temperature (- < ), pasty ran*e ( -5-
solder alloys
Solder alloy - m o" - s o" - < o" -5 - < !- S o" ( C*)
Sn!'SbSn!'Sb! .'"uSn!'Sb! .'"u! .'0n1
%9G. 66. G
%.%'
'.'9
%7%G.%G.%9
7..66
&.7
& '.'66.79
!atent eat of 1usion
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& '.' and 66.7G C*, respecti$ely. -hese results re lect that, the SS"! .'0n1 has lo2ered
consumed ener*y or meltin* process than SS"' ' solder.
'.$ *icrostructure Characteri2ation
J!ray di raction in$esti*ation o SS"' ' solder and SS"! .'0n1 composite
solders are illustrated by the di raction pro iles sho2n in Fi*. a!b. -hey are e:hibited
three types o phases> !Sn, SbSn and "u 9Sn ' ( M"s). -he di raction pro iles o both
solders are analysis, and deduced that, they ha$e same unit cell o body central tetra*onal
(+"-) lattice eatures.
-he di raction pea?s inde:ed to Sn clearly e:ist or both o in$esti*atin*
samples, but no pea?s belon*in* to 0n1 appear. -he e:amined J/D pattern o the
SS"' ' e:hibited a reduced pea? intensity compared to J/D pattern o SS"!0n1,
but the relati$e ma*nitude o the pea?s remains the same. n addition, increased
pea? broadenin* 2as obser$ed 2ith present 0n1 nano sized particles. -he a$era*e *rain
size o the !Sn 2as calculated rom the di raction pea? 2idth usin* the Scherrer
e@uation. As it is 2ell ?no2n, *rain size 2as ound to !!!!!!. -he SS"!0n1
composite solder alloy has an a$era*e *rain size o & nm, 2hich is si*ni icantly
smaller than the &G' nm obtained rom the unrein orced Sn coatin*. -he presence o 0n1 in a metal matri: may induce smaller *rains due to a lar*e increase o
nucleation sites. Namely, the *ro2th o the "u 9Sn ' is a competition bet2een nucleation
and crystal *ro2th. -he 0n1 nano particles pro$ide more nucleation sites and, hence,
slo2 up the crystal *ro2th> subse@uently, the correspondin* Sn matri: and Sb in
the composite has nearly a similar crystal size . -he de ects on the SS"!0n1 pro$ide
acti$e nucleation sites or the Sn and produce core!shell!li?e structures, 2hich 2ere
reported to be bene icial or accommodatin* stresses arisin* rom $olume increase :
durin* intercalation.
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Moreo$er, optical microscope ma*es (1M) or the microstructure o SS"' '
solder alloy and SS"! .'0n1 composite solder are sho2n in Fi*. a!b. Fi*ure b
e:hibited a si*ni icantly reduction in the *rain size o the !Sn matri: o the SS"!0n1
composite solder 2hen compared 2ith those in the SS"' ' solder alloy as sho2n in Fi*.
a. Also it can be obser$ed that, durin* solidi ication dendritic net2or? 4 !Sn, dar?
re*ions8 and interdendritic 4bri*ht re*ions8 consistin* o 2hite dots particles 4SnSb M"8
besides irre*ular platelets shapes 4"u 9Sn ' M"8. -hese particles identi ied by study o J!
ray di raction pea?s and the ener*y dispersi$e J!ray analysis (EDJ). Fi*ure a is
depicted the bri*ht dots o SnSb particles dispersed 2ithin the Sn!rich matri: besides
irre*ular poly*ons o "u 9Sn ' intermetallic compounds ( M"s). Fi*ure b re$ealed the
microstructure o the SS"! .'0n1 composite solder alloy. t represents the same eatures
in the microstructure o the SS"' ' solder. Mean2hile, the !Sn dendrites are uni ormly
re ined distributes as 2ell as the M"s particles are reduced in size, 4i.e. seem to be
small and ine compared 2ith those in SS"' ' solder alloy8, this is due to 0n1 nano!
sized play an important role to promote a *reat uni orm nucleation seeds durin*
solidi ication. Moreo$er, Moreo$er, 0n1 nano!particles ha$e hi*hly acti$e sur ace area
that support the stron* adsorption e ect o "u atoms, there ore reduced the e:cessi$e
*ro2th o "u 9Sn ' M" 2ithin S""! .'0n1 composite lead ree solder. (re .)
-he presence o these M"s is con irmed by EDJ analysis that e:hibited in Fi*.
%a!b. -he addition o .' 2t3 nano!sized 0n1 particles has *reat e ect on microstructure
o SS"' ' solder.
Accordin* to the EDJ analysis illustrates in Fi*. %a!b, the in$esti*ated area o
specimens 2as contained 0n, 1, "u, Sn and Sb atoms. -his means that, the presence o
0n1 to SS"!' ' alloy suppress the ormation o the !Sn dendrites, SnSb and "u 6Sn '
( M"s) yieldin* a uni orm dispersion 2ithin the Sn!rich mi:ture that *eneratin* a ine
net2or? microstructure 2ith the !Sn matri:.
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'-' *echanical properties
Fi*. sho2s the typical tensile stress strain cur$es o the lead ree composite solder
specimens at a constant strain rate o &:& ! s!& at di erent temperatures. -he a$era*e$alues o tensile stren*th and elon*ation o the lead! ree composite solder alloys are
*i$en in -able . -he lead! ree SA" solder had an ultimate tensile stress (#-S) o ''.G
MPa, . 3 o set strain ( . ;S) o ' . MPa, and elon*ation o %6.93. Addition o 0n1
nanopo2der had a si*ni icant e ect on the #-S o lead! ree SS" composite solders. For
e:ample, the #-S and . ;S rose to G .& MPa and 97. MPa, respecti$ely. o2e$er, the
total elon*ation o the lead! ree SS" solder containin* 0n1 nanopo2der 2as less than
that o the lead! ree SS" solder ( '. 3 $s.%6.93). -he in luence o 0n1 nanopo2der
rein orcement on tensile properties o the SS" composite solder is also summarized in
-able . /esults re$eal that the tensile properties o the composite solder rises 2ith
increased addition o 0n1 nanopo2der to a lead! ree SS" mi:ture. -his indicates that i
the 0n1 nanopo2ders addition is increased, the composite solder can be impro$ed due to
the presence o 0n1 nanopo2ders as rein orcement.
-his could be attributed toK (&) pinnin* *rain boundaries and thus impedin* slidin* o the
*rain boundaries, ( ) the increase o dislocation densities and obstacles to restrict the
motion o dislocation and ( ) the hardenin* mechanism o the matri: and 0n1
nanopo2ders 48. o2e$er, ductility decreased because o a lar*e amount o micro!
porosity alon* *rain boundaries and crac? nucleation sites in the orm o hard and brittle
0n1 nanopo2ders 48.
-he ultimate tensile stren*th ( #-S ) is the ma:imum stress 2hich a material can
2ithstand in tension. ith the addition o .'2t3 0n1 nano!particle, the mechanical
properties 2ould be a ected. t 2as sho2n in Section 4 ! 8 that the microstructure 2as*enerally re ined 2hen 0n1 nano!particle 2as added. t is oreseen that the tensile
properties 2ill be impro$ed. -he results o tensile tests on SS" lead! ree solder alloy are
sho2n as Fi*. 6. -he tensile stren*ths are impro$ed by 0n1 nano!particle addition but,
the elon*ation to ailure o the solder alloy becomes lo2er. -his may be due to the
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increase in the @uantity o the hard 0n1 particles 4 8. For e:ample, as sho2n in Fi*. 7, the
SS"' ' alloy has #-S o about MPa, 2hen 0n1 nano!particle 2as added the #-S is
increased by appro:imately 3 to become about 9 MPa. ith the addition o 0n1
nano!particle, the elon*ation to ailure is decreased. n particular, it is still comparable
2ith that o the Sn!Pb solder alloy.
t is also be noticed that, the tensile data are *enerally analyzed by relatin* the
steady!state strain rate to the stress throu*h a po2er!la2 relation. -he stress e:ponent RnR
and the acti$ation ener*y (W c) or tensile tests can be calculated rom the Dorn e@uation 4
2here W c represents the acti$ation ener*y or creep, n the po2er!la2 stress
e:ponent, X the temperature!dependent shear modulus, b the +ur*ers $ector, A
a material!dependent constant, / the uni$ersal *as constant and - is the temperature. -he
$alues o n and W c are representati$e o the dominant creep mechanism.
-he tensile beha$ior o the Sn 7' Sb ' alloy has been in$esti*ated by *oshe$ et al.
and they ound that microcrac?s nucleate because o decohesion alon* the matri:Cparticle
boundaries 4 8. -he SnSb and Sn 9"u ' intermetallic particles play t2o di erent roles. -hey
may stren*then the alloy matri: and pre$ent the ormation o lar*e dislocation pile!ups at
*rain boundaries. 1n the other hand, the hi*her number o particles in a *i$en matri:, the
more matri:Cintermetallics inter aces it contains, leadin* to a hi*her li?elihood o microcrac? nucleation that can speed up the ailure process. n 48, 1ne o the ma or
results is con irmin* that the steady!state strain rate o SnSb ' is controlled by the
dislocation!pipe di usion in the Sn matri:.48 -he data o lo2 stress under di erent
temperatures and stresses o SS"' ' and SS"! .'0n1 are presented in Fi*. &&. ith the
addition o the 0n1 nano!particles, the lo2 stress decreased substantially.
'.' )ensile responseA typical set o representati$e stress strain cur$es o the SS"' ' solder and SA" .'0n1
composite solder are sho2n in Fi*. 7 a and b . -he sets o stress strain cur$es o the
solders stretched by a constant strain rate o G.%:& !% s!& at the de ormation temperatures
76, , %6 and G . From these i*ures, it is noted that le$els o the stress strain
cur$es shi ted to2ards hi*her $alues by decreasin* the testin* temperatures. Moreo$er,
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addition o 0n1 is noticed to increase the le$el o the stress strain cur$es at all test
conditions (Strain rate and testin* temperature). n details, stress strain characteristics
namely the ultimate tensile stress #-S , the yield stress y . , racture stress and total
elon*ation o both SS"' ' solder and SS" .'0n1 composite solder are stron*ly
a ected by the $ariation o the testin* temperature and the e:istence o the nano!sized
0n1 particles as e:hibited in i*ure & a!c. For both solders at the constant strain rate,
raisin* the testin* temperature resultin* a continuous so tenin* and lo2er $alues o #-S ,
y and 2ere obser$ed. +ut, the total elon*ation o SS" .'0n1 composite solder 2as
less than that o SS"' ' solder. -he results indicate that, the presence o nano!sized 0n1
particles rein orced the tensile characteristics but also diorites the ductility o SS"' '
solder. o2e$er, ductility decreased because o a lar*e amount o micro!porosity alon*
*rain boundaries and crac? nucleation sites in the orm o hard and brittle 0n1 nano!
po2ders48.
ndeed, the nano!size particles are dispersed uni ormly and homo*eneously
distributed in metal matri: 2hich pro$ide hi*h barrier by impedin* *rain boundary
slidin* and also dislocation mo$ement 4 8. Furthermore, their rein orcement pro$ides
su icient loc?in* o the *rain boundaries to limit *rain boundary *lidin* or slidin* as
result enhance the creep resistance and mechanical characteristics. -his could be
summarized the in luence o the nano!size particles in K (&) pinnin* *rain boundaries and
thus impedin* slidin* o the *rain boundaries, ( ) the increase o dislocation densities and
obstacles to restrict the motion o dislocation and ( ) the dispersion hardenin* mechanism
o the matri: and 0n1 nano!po2ders 48
Accordin* to the a*ner
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ha$e a hi*her lo2 resistance than the matri:, and be un!de ormable and resistant to
racture 4&G8. -hat is, nano!sized particles or ibers are seen as the best candidate as
rein orcement particles.
Fi*ure &
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Fi*ure
-ables summarizes the di raction lines o the phases and d!$alue or SA"! . solder
alloy
$
Arbitrary #nits
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Fi*. a 1M ima*e o (SS"' ')
Fi*. b 1M ima*e o (SS"! .'0n1) at room temperature (& J)
Fi*. % a!b
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Fi*ure 'a> FE!SEM ima*e o SS"' 'Fi*. (%b) EDJ analysis o "u!Sn M"s
Fi*ure 9a> FE!SEM ima*e o SS"' 'Fi*. ('b) EDJ analysis o "u!Sn M"s
Fi*ure Ga> FE!SEM ima*e o SS"' 'Fi*. (Gb) EDJ analysis o "u!Sn M"s
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Fi*ure 6a> FE!SEM ima*e o SS"! .'0n1Fi*. (Gb) EDJ analysis o eutectic re*ion M"s
Fi*. 6 SS"!0n1 as resa$ed
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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SS"!0n1
SS"' '
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8/10/2019 effect of ZnO nanoparticles on thermal, microsture and tensile properties of SSC505 lead free solder alloys (Sn_5S
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Fi*ure (7) sho2s the tensile properties o SS"' ' and S"" .'0n1 at di erent
temperatures
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Fi*ure ()
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