ARCHIVES OF METALLURGY AND MATERIALS
Volume 59 2014 Issue 2
DOI: 10.2478/amm-2014-0123
K. MAJOR-GABRYŚ∗, S.M. DOBOSZ∗, P. JEL´
INEK∗∗ , J. JAKUBSKI∗, J. BE ˇ
NO∗∗
THE MEASUREMENT OF HIGH-TEMPERATURE EXPANSION AS THE STANDARD OF ESTIMATION THE KNOCK-OUT
PROPERTIES OF MOULDING SANDS WITH HYDRATED SODIUM SILICATE
POMIAR EKSPANSJI WYSOKOTEMPERATUROWEJ JAKO KRYTERIUM OCENY WYBIJALNOŚCI MAS FORMIERSKICH
Z UWODNIONYM KRZEMIANEM SODU
The necessi y o ecei ing high quali y cas ings o ces unde aking esea ch o elabo a e moulding and co e sands ensu ing
ob aining he ma e ials wi h ele an echnological pa ame e s and also wi h high en i onmen al s anda ds. The mos impo an
g oup he e a e moulding sands wi h hyd a ed sodium silica e. Un o una ely, hei undamen al disad an ages a e weak knock-ou
p ope ies. The a icle p esen s he mos commonly used me hods o measu ing he knock-ou p ope ies o moulding and
co e sands. The au ho s p opose a new me hod o es ima ion his pa ame e . The me hod is based on he measu emen o
high- empe a u e expansion.
Keywo ds: moulding sand, hyd a ed sodium silica e, knock-ou p ope ies
Po zeba uzyskiwania wysokiej jakości odlewów wymusza podejmowanie p ac badawczych dla o zymania mas o mie -
skich i dzeniowych zapewniających uzyskanie wo zyw o odpowiednich pa ame ach echnologicznych, jednocześnie speł-
niających wysokie wymogi och ony ś odowiska. Najważniejszą g upę s anowią u aj masy z uwodnionym k zemianem sodu.
Nies e y jedną z ich pods awowych wad jes słaba wybijalność. W a ykule zos ały p zeds awione najczęściej s osowane me ody
pomia u wybijalności mas o mie skich i dzeniowych. Au o zy zap oponowali nową me odę oceny wybijalności opie ającą się
na pomia ze ekspansji wysoko empe a u owej.
1. In oduc ion
The necessi y o ecei ing high quali y cas ings o ces
unde aking esea ch o ob ain moulding and co e sands p o-
iding o ob ain ma e ials wi h ele an echnological pa a-
me e s and also wi h high en i onmen al s anda ds. Many na-
ional and o eign scien i ic cen e s [1-12] unde ake scien i ic
esea ch aiming o elabo a e new binding sys ems based on
non oxic ino ganic binde s. The mos impo an g oup he e
a e moulding sands wi h hyd a ed sodium silica e. Un o u-
na ely hei main disad an age a e low knock-ou p ope ies
and low abili y o mechanical eclama ion.
Fo es ima ion o ac ions imp o ing moulding sands’
knock-ou p ope ies i ’s undamen al o use he app op ia e
measu emen p ocedu e. In he a icle he e a e p esen ed he
mos commonly used me hods o measu ing he knock-ou
p ope ies o moulding and co e sands. The e is also p oposed
a new me hod based on measu ing high- empe a u e expansion
o es ed moulding sands.
2. Knock-ou p ope ies o moulding and co e sands
The knock-ou p ope ies a e de ined as moulding o co e
sand’s abili y o easy smashing ou (pou ing ou ) om mould
(moulding sand) o om cas (co e sand) a e cooling he
cas o knocking-ou empe a u e [13]. The knock-ou p ope -
ies a e es ima ed by echnological me hods and acco ding o
e ained s eng h R k
cmeasu emen .
2.1. Technological me hods – he me hod ecommended
by Polish S anda d no PN-85/H-11005
In echnological me hod ecommended by Polish S an-
da d he e a e used s anda d cylind ical samples (ø50×50 mm)
p epa ed om es ed moulding sand [13]. The samples a e
ea ed exac ly as moulds and co es being p oduced om he
es ed sand. The samples a e no co e ed wi h any p o ec i e
coa ings. The samples (co es) a e pu inside he mould wi h
usage o special model (sample ). The liquid ound y alloy is
pou ed in o he mould. The alloy empe a u e should be he
same as i is while p oducing cas s in es ed moulding sand.
A e cooling he cas o ambien empe a u e, i is pu – wi h
he samples (co es) – in de ice LUW-C o LUW-CA (au o-
∗AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, FACULTY OF FOUNDRY ENGINEERING, DEPARTMENT OF MOULDING MATERIALS, MOULD TECHNOLOGY AND FOUNDRY OF
NON-FERROUS METALS, AL. A. MICKIEWICZA 30, 30-059 KRAKOW, POLAND
∗∗ VSB – TECHNICAL UNIVERSITY OF OSTRAVA, FACULTY OF METALLURGY AND MATERIAL ENGINEERING, DEPARTMENT OF METALLURGY AND FOUNDRY ENGINEERING, CZECH
REPUBLIC
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ma ically) cons uc ed o measu e moulding sand’s knock-ou
p ope ies. The de ice is equipped wi h a pin which knocks
he sample (co e) ou he cas . The wo k o one pin bea is
1,63 J [13]. The knock-ou measu emen is he wo k necessa y
o mo ing he sample (co e) ou he cas . I is calcula ed om
he o mula 1 [13].
Lw=1,63 ·n;J(1)
whe e: 1,63 – wo k o one weigh bea , J,
n – numbe o weigh bea s ill mo ing he co e ou he
cas .
The e a e also used o he echnological me hods o mea-
su ing moulding sands knock-ou p ope ies including Russian
and F ench es s [13].
2.2. The me hod based on e ained s eng h R k
c
measu emen
The me hod is based on measu emen o e ained s eng h
R k
cchange o moulding sand wi h hyd a ed sodium silica e
wi h empe a u e inc easing. The es begins wi h measu ing
s eng h o moulding sand in ambien empe a u e, hen –
beginning in 100◦C – he empe a u e is inc easing and he
s eng h is being measu ed a e e e y 100◦ ill eaching he
empe a u e 1000◦C. A e cooling he samples o ambien
empe a u e he e ained s eng h (R k
c) o es ed moulding
sand is measu ed. The esul s a e pu on he g aph show-
ing he in luence o empe a u e on moulding sand’s e ained
s eng h (R k
c). Acco ding o he eached g aph i ’s possible
o es ima e he moulding sand’s knock-ou p ope ies. Good
knock-ou p ope ies has he pa o moulding sand hea ed
o he empe a u e in which i s e ained s eng h (R k
c) is he
lowes and he pa o moulding sand hea ed o he empe a u e
in which i s e ained s eng h (R k
c) is high cha ac e izes wi h
bad knock-ou p ope ies [13].
2.3. The cu e o e ained s eng h (R k
c) o moulding
sand wi h hyd a ed sodium silica e
The e a e h ee ex eme poin s on ypical cu e o e-
ained s eng h (R k
c) o moulding sand wi h hyd a ed sodium
silica e:
–The 1s maximum in he empe a u e o abou 200◦C,
–The minimum in he empe a u e o abou 600oC,
–The 2nd maximum in he empe a u e o abou 800◦C.
Mos o he au ho s [13, 15] explain occu ing he 1s maxi-
mum as he esul o binde dehyd a ion p ocess and he main
ole is assigned o he dehyd a ion o unbound hyd a ed sodi-
um silica e. The au ho [15] explains occu ing he 1s max-
imum acco ding o DTA cu e o hyd a ed sodium silica e.
The cu e shows ha in he ange o empe a u e 350-400◦C
begins endo he mic p ocess wi h endo he mic peak egis e ed
in he empe a u e o 600◦C. The analysis p o ed he p es-
ence o wo endo he mic peaks in empe a u es o 130 and
640◦C is p obably esponsible o he compound dehyd a ion
p ocess. Acco ding o he au ho [15] in case o sel ha dened
moulding sands p epa ed in es e echnology he 1s maxi-
mum doesn’ occu – he e is cons an dec ease o e ained
s eng h beginning wi h high alues in ambien empe a u e o
he minimum in empe a u e o 600◦C [15]. T ans o ma ion
o qua z βα conside ed p e iously as he cause o occu ing
he minimum (600◦C) acco ding o he au ho [15] can’ be
he only eason o occu ing his ex eme. The au ho p o ed
ha moulding sands wi h hyd a ed sodium silica e based on
zi conium sand g ains has he minimum in his empe a u e as
well. The minimum was also eached by es ing he s eng h
o bound hyd a ed sodium silica e wi hou sand g ains. The
au ho sugges s ha he e a e di e en ac o s causing his
ex eme which a e among all – dehyd a ion p ocesses o dis-
odium silica e and silicic acid gel [15]. A e he minimum
he e is a apid inc ease o e ained s eng h wi h he max-
imum in he empe a u e o 800-900◦C. The 2nd maximum
is caused by o ma ion o he liquid phase (mel ing he hy-
d a ed sodium silica e) and by he eac ion o Na2CO3wi h
SiO2ending wi h o ma ion o Na2O·2SiO2[15]. Beyond he
2nd maximum he e is a apid dec ease o e ained s eng h
(R k
c) wha J.L. Lewandowski [13] explains as a esul o he
iola ion o he binde shell s uc u e on qua z sand g ains,
caused by a la ge change in olume o qua z. In he p esence
o Na2O con e sion o c is obali e can begin al eady abo e
800◦C.
2.4. The p oposal o new me hod o knock-ou
p ope ies’ es ima ion
As i was ini ially e e ed in he p e ious pa o he a -
icle, he me hod o es ima ion o he knock-ou p ope ies o
moulding sands based on e ained s eng h (R k
c) measu emen
can’ be used in whole empe a u e ange.
The use o e ained s eng h measu emen o es ima ion
he knock-ou p ope ies o moulding sands is no clea . The
au ho [15] p o ed ha moulding sand’s expansion is espon-
sible o e ained s eng h dec ease beyond he 2nd maximum.
The p ocess is caused by ansi ion o α-SiO2phase in o
c is obali e which is ca alyzed by Na+ions, qua z densi y de-
c eases om 2650 o 2330 kg/m3wi h inc easing he mass
olume o abou 40%. Despi e his moulding sand’s e ained
s eng h is low in empe a u es highe han 1000◦C. The au-
ho [15] p o ed ha he e is he ypical 2nd maximum in he
empe a u e o abou 800◦C on e ained s eng h o mould-
ing sands wi h hyd a ed sodium silica e and es e ha dene s
cu e, bu he ene gy necessa y o knocking he sample ou
while using echnological me hod inc eases ill 1000◦C. The
phenomena is caused by c is obali ic qua z sand expansion
which is mainly esponsible o e ained s eng h dec ease be-
yond he 2nd maximum, inc eases he inal moulding sand’s
densi y causing wo se knock-ou p ope ies.
Acco ding o his, au ho s o he pape elabo a ed a new
me hod o es ima ion o moulding sand’s knock-ou p ope ies.
The base was he analysis o co es o moulds beha io du ing
pou ing p ocess – he p ocess causes moulding sand expan-
sion. Howe e his phenomena is inhibi ed by cas su ace
(co e sands) o by cas and moulding box (moulding sands).
S ong in e nal s ess occu s in moulding sand which inhibi s
i s e acua ion om he cas o om he moulding box. The
highe in e nal s ess is he wo se knock-ou p ope ies a e.
Moulding sand expansion measu emen a e pou ing
p ocess may be use ul o es ima ion o moulding sand’s
knock-ou p ope ies.
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3. Own esea ch
The e we e es ed moulding sands wi h hyd a ed sodi-
um silica e and liquid ha dene s p epa ed in sel ha dened
moulding sands echnology (es e me hod). The esea ch was
conduc ed a e 24h o ha dening wi h keeping cons an em-
pe a u e and humidi y in esea ch oom. The au ho s used
s anda d and modi ied moulding sands wi h hyd a ed sodium
silica e o p o e he necessi y o elabo a ing new me hod o
knock-ou p ope ies measu emen . As a ac o modi ying es -
ed moulding sands he e we e used own, pa en ed [16] addi i e
called Glassex [17].
The ollowing moulding sands composi ions we e aking
in o esea ch:
•Sand g ains: qua z sand 100 pa s by weigh
•Binde : hyd a ed sodium silica e 3 pa s by weigh
•Ha dene : lodu 0,3 pa by weigh
•Addi i e: Glassex 1 pa by weigh .
3.1. The es ima ion o moulding sands’ knock-ou
p ope ies acco ding o Polish S anda d no
PN-85/H-11005
As he i s me hod o es ima ion o moulding sands’
knock-ou p ope ies he e was used he me hod acco ding o
Polish S anda d no PN-85/H-11005. The e we e es ed mould-
ing sands wi h and wi hou Glassex addi i e. In he expe imen
he e we e used cylind ical samples. The samples we e pu in
expe imen al cas and pou ed wi h cas s eel ha ing he em-
pe a u e o abou 1450◦C. A e cooling he cas s we e gen ly
knocked ou he mould and he echnological knock-ou p op-
e ies measu emen we e ca ied ou . The esul s a e shown
in igu e 1 [18].
Fig. 1. Knock-ou p ope ies o moulding sands wi h hyd a ed sodi-
um silica e wi h and wi hou Glassex addi i e measu ed by Polish
S anda d no PN-85/H-11005 [18]
The conduc ed esea ch shows mo e han wice educ ion
o wo k necessa y o knocking he co e ou he expe imen al
cas while using Glassex addi i e as a componen o moulding
sand wi h hyd a ed sodium silica e.
3.2. The es ima ion o moulding sands knock-ou
p ope ies acco ding o e ained s eng h R k
c
measu emen
The cylind ical samples (p epa ed like in chap e 3.1)
we e hea ed in labo a o y elec ical u nace SNOL 8,2/1100
(P) in he ange o empe a u e 100-1100◦C (e e y 100◦) and
in mu le u nace FCF 7 SHM in empe a u e 1200◦C. The
samples we e kep in each empe a u e o 15 min and we e
cooled wi h he u nace o ambien empe a u e. Then hei
e ained s eng h R k
cwas measu ed using es ing machine IN-
STRON con olled wi h mode n con ol sys em Tes S a IIS.
The esul s a e shown in Fig. 2 [19].
Fig. 2. Knock-ou p ope ies o moulding sands wi h hyd a ed sodi-
um silica e wi h and wi hou Glassex addi i e es ima ed acco ding o
e ained s eng h R k
cmeasu emen [19]
Inse ing he Glassex addi i e o moulding sands wi h hy-
d a ed sodium silica e causes change o hei e ained s eng h
R k
ccu e shape. The e is no 1s and 2nd maximum on he
cu e. Moulding sand wi h Glassex addi i e has lowe e ained
s eng h R k
cin he ange o empe a u e 200-1000◦C. The
in luence o Glassex addi i e on moulding sands knock-ou
p ope ies was desc ibed in de ails in p e ious publica ions
[19].
The au ho s p o ed ha e ained s eng h R k
ccan’ be used
as he c i e ia o knock-ou p ope ies es ima ion in he a ea
beyond he 2nd maximum – which was desc ibed in he chap e
2.4. Tha ’s why he e is p oposed a new me hod o es ima ion
o moulding sand’s knock-ou p ope ies. The me hod is based
on high- empe a u e expansion measu emen .
3.3. The es ima ion o moulding sands knock-ou
p ope ies acco ding o high- empe a u e expansion
measu emen
The e we e used cylind ical samples p epa ed and hea ed
acco ding o me hods desc ibed in chap e s 3.1 and 3.2. The
samples we e measu ed be o e and a e hea ing in he ange
o empe a u e 600-1200◦C e e y 100◦acco ding o li e a u e
da a [15, 20]. The esul s a e shown in Fig. 3 [19].
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Fig. 3. Knock-ou p ope ies o moulding sands wi h hyd a ed sodi-
um silica e wi h and wi hou Glassex addi i e es ima ed acco ding o
high- empe a u e expansion measu emen [19]
The conduc ed esea ch p o ed ha inse ing he Glassex
addi i e o moulding sands wi h hyd a ed sodium silica e caus-
es lowing hei high- empe a u e expansion which imp o es
hei knock-ou p ope ies. In he empe a u e o 600◦C he
high- empe a u e expansion is abou 50% dec eased; 700oC –
abou 90%, 800◦C – abou 60%, 900◦C – abou 70%, 1100◦C
– abou 50%, 1200◦C – abou 40%. The Glassex addi i e
inhibi s high- empe a u e expansion o es ed moulding sands
– educes hei in e nal s esses – inc easing hei knock-ou
p ope ies.
4. Conclusions
Acco ding o li e a u e da a and own esea ch he ollow-
ing conclusions may be speci ied:
1. The me hod o es ima ing he knock-ou p ope ies o
moulding sands wi h hyd a ed sodium silica e acco ding o
hei e ained s eng h R k
ccu e beyond he 2nd maximum
is no eliable.
2. The me hod o es ima ing he knock-ou p ope ies o
moulding sands wi h hyd a ed sodium silica e acco ding
o hei high- empe a u e expansion measu emen seems
o be much mo e eliable.
3. Inse ing he Glassex addi i e shows o e 50% inc ease o
es ed moulding sands knock-ou p ope ies measu ed ac-
co ding o hei high- empe a u e expansion. This is con-
sis en wi h he esul s o conduc ed echnological me hod.
4. The measu emen o high- empe a u e expansion may be
one o he s anda ds o es ima ing he knock-ou p ope ies
o moulding sands wi h hyd a ed sodium silica e.
Acknowledgemen s
Scien i ic esea ch inanced om AGH, No 11.11.170.318-3.
REFERENCES
[1] A.E. Z a d o , Li ejnoje P oiz ods o 9, 38-39 (2000).
[2] I. Va ˇ
s k o a, S udium niek o ych spoji o ych sys emo
o mo acich a jad o ych zmiesi o z ’ahu k ekologizacii
zlie a ens a. PhD hesis, Technicka uni e zi a, Koˇ
sice, Janua y
2002.
[3] A. W o l , T. S e i n h a e u s e , Giesse ei 91, 6, 80-84
(2004).
[4] R. G o s c h, Giesse ei Rundschau 51, 7/8, 139-142 (2004).
[5] M. K o z e n i o w s k a, A. B a l i ń s k i, Ma e ialo e
inzinie s o 10, 3, 291-294 (2003).
[6] E. F l e m i n g, H. P o l z i n, T.J. K o o y e s, Giesse ei-P ax.
9/10, 177-183 (1996).
[7] A.P. N i k i o o , A.V. A o n a s k i n, V.A. B e g m a,
Li ejnoje P oiz ods o 4, 14 (1997).
[8] M. S a c h o w i c z, K. G a n a , D. N o w a k, A chi es o
Found y Enginee ing, Special Issue, 11, 2, 203-208 (2011).
[9] K. G a n a , B. O p y d, M. S a c h o w i c z, G. J a -
w o s k i, A chi es o Me allu gy and Ma e ials 58, 3, 919-922
(2013).
[10] S. G o b e i s, V. A n o n o i c h, Li ejnoje P oiz ods o 8,
22-24 (2002).
[11] J. D a ń k o, J. K a m i ń s k a, M. S k z y ń s k i, A chi es o
Me allu gy and Ma e ials 58, 3, 993-996 (2013).
[12] K.E. N e e d o , Li ejnoje P oiz ods o 1, 18-20 (2004).
[13] J.L. L e w a n d o w s k i, Two zywa na o my odlewnicze,
K aków 1997.
[14] S .M. D o b o s z, Woda w masach o mie skich i dzeniowych,
K aków 2006.
[15] P. J e l i n e k, Poji o e sous a y sle a enskych o mo acich
smesi, Os a a 2004.
[16] Pa en PL 206691 B1: Masa o mie ska lub dzeniowa ze
szkłem wodnym, udzielona 30.09.2010.
[17] K. M a j o - G a b y ś, S .M. D o b o s z, A chi es o
Found y Enginee ing 7, 1, 127-130 (2007).
[18] S .M. D o b o s z, P. J e l i n e k, K. M a j o - G a b y ś, Chi-
na Found y 8, 4, 438-446 (2011).
[19] K. M a j o - G a b y ś, S .M. D o b o s z, J. J a k u b s k i,
Manu ac u ing Technology 13, 1, 68-73 (2013).
[20] I.S. S y ˇ
c e , Li ejnoje P oiz ods o 6, 31-37 (1965).
Recei ed: 10 Janua y 2014.
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