Morphology of graphite precipitates in austenitic ductile iron · Morphology of graphite...

A R C H I V E S

O f

F O U N D R Y E N G I N E E R I N G

Published quarterly as the organ of the Foundry Commission of the Polish Academy of Sciences

ISSN (1897-3310) Volume 11

Issue 2/2011 149–152

29/2

Morphology of graphite precipitates in austenitic ductile iron

K. Zarębski P

aP, P. Putyra P

bP, B. Khatemi P

cP, A. Tabor P

dP

P

a, dP Cracow University of Technology, Institute of Materials Engineering, al. Jana Pawła II 37, 31 864 Kraków, Poland

P

bP The Institute of Advanced Manufacturing Technology, ul. Wrocławska 37a, 30-011 Kraków, Poland

P

cP Université de Tiaret Algérie

Abstract

TThe final mechanical properties of cast iron depend on the nature and properties of the matrix and on the morphology of graphite precipitates. The article presents the results of studies of the structure of austenitic ductile iron with different nickel content. The studies include the identification and stereological description of graphite precipitates. The volume fraction of graphite in cast iron was determined in function of the size of the precipitates and the adopted shape coefficient of single particles, enabling the content of regular spheroids to be estimated.

Keywords: ductile iron, austenite, graphite structures, irregular, exploded, vermicular

1. Introduction TThe use of austenitic ductile iron for structures operating at

low temperatures is essential in the case of castings with intricate shapes, requiring difficult and costly machining. To confer to these castings the required high mechanical properties, it is necessary to maintain within the range of their operating temperatures the matrix of an austenitic structure. Structure of this type offers high-nickel cast iron with spheroidal graphite [1 - 3].

T

The spheroidisation of graphite increases the resistance of austenitic cast iron to the effect of corrosive environments, while maintaining the high mechanical properties in a wide range of temperatures [4-7]. The high resistance to corrosion of austenitic ductile iron is obtained not only through the favourable shape of graphite, but also through the low content of non-metallic inclusions during spheroidisation, thus reducing the risk of the formation of microcells intensifying the destruction of castings [5]. The degenerated forms of graphite adversely affect the mechanical and plastic properties of cast iron, as disclosed by successive studies [8-11]. This study presents the results of

structural examinations, which aim at a quantitative description of the morphology of graphite precipitates in austenitic ductile iron with different nickel content.

T

2. Test material TStudies were conducted on cast iron from 4 melts with nickel

content of 17%, 20%, 25% and 30%. The chemical composition and designation of individual melts are given in Table 1.T

T

The spheroidisation process was carried out with a FeNiMg1 master alloy, while for inoculation of the cast iron, Si75A ferrosilicon added in an amount of 0.5-0.7wt.% in respect of the iron melt weight was used. Ingots of YII type were cast in accordance with BS EN 1563:2000 in sand moulds made from bentonite sands. The cast iron was melted in a medium frequency induction furnace with crucible of 60kg capacity. The melt temperature was 1490°C; the spheroidisation of cast iron was carried out in a ladle at the temperature of 1430°C. Moulds for

A R C H I V E S O F F O U N D R Y E N G I N E E R I N G V o l u m e 1 1 , I s s u e 2 / 2 0 1 1 , 1 4 9 – 1 5 2 149

cast ingots were poured when melt temperature reached the value of 1390 °C.

T

Table 1. Chemical composition of the examined materials.

3. Methodology TThe aim of the study was to determine the volume fraction of

the graphite precipitates and find out what proportional share in these precipitates have those which in terms of their shape can be classified as regular. Observations under a Nikon Eclipse ME600P optical microscope were carried out on the randomly selected, not overlapping areas of metallographic specimens of the size of 754×570 pixels, each of which corresponded to the actual metallographic section surface area of 1.44 mmP

2P. The

stereological measurements were performed by planimetry using ImageJ computer software for image editing, processing and analysis. The number of areas available for each analysed case of the material condition ensured total of over 1,500 examined objects, i.e. graphite precipitates. The degenerated graphite, differing in its shape from the spheroidal one, was classified according to standard reference patterns (vermicular, spiky, coral, exploded). As parameters for the quantitative determination of the precipitate type, using automated image analysis methods, the shape coefficients as defined in Table 2 were adopted. Table 2. Quantitative shape parameters

Name Sign of shape coefficients

Circularity 214U

Af ⋅=

π

Round 224

MajorAxisAf

⋅⋅

=π

Folding A

Uf

f⋅

==π4

1 2

13

U – perimeter, A – area T

The spheroidal graphite includes the precipitates for which the values of the coefficients f

B

1B

and fB

2B

are at least 0.8 (fB

3B

<1.25). The method and example of the elimination of degenerated graphite are shown in Figure 1

T

T

Table 3 shows examples of graphite precipitates and corresponding values of the shape coefficients. Table 4 gives examples of graphite particles and values of the shape parameter f

B

3B

corresponding to the class intervals adopted in determination of the quantitative and volumetric graphite fractions in the examined cast iron.

T

a) b)

c) d)Fig.1. Elimination of the degenerated graphite precipitates, (marker: 100um); a) image of microstructure, b) image after

binarisation, c) image after elimination of graphite of parameter fB2 B< 0,8, d) image after elimination of graphite of parameter

fB3 B> 1,25

Table 3. Examples of graphite precipitates and the corresponding values of shape coefficients

Values of shape coefficients Example of the graphite precipitate shapes fB2B fB3B

spheroidal 0,95 1,19

irregular 0,672 1,44

exploded 0,86 4,00

Table 4. Class intervals adopted for shape determination and the corresponding shapes of graphite precipitates

Class No.

Example of graphite precipitate shape

Values of shape

coefficient fB3B

1 1,0

2 1,0÷1,2

3 1,2÷1,6 4 1,6÷2,4 5 2,4÷4,2

6 > 4,2

4. The results of studies T

Graphs in Figure 2 present histograms of volume fractions of graphite and spheroidal graphite in different classes of the precipitate diameter size. Figure 3 shows the frequency of

Content in mass % Melt

C Si Mn P S Mg Ni

A 3,15 2,00 3,85 0,045 0,020 0,20 16,50 B 3,15 2,15 3,90 0,050 0,020 0,22 19,7 C 2,95 2,25 3,95 0,045 0,020 0,21 25,0 D 2,80 2,20 3,90 0,040 0,020 0,25 30,5


occurrence and volume fraction of graphite precipitates in classes determining the shape of a single particle in accordance with Table 4. The values of selected stereological parameters for individual melts are summarised in Table 5 (the results are given

at the assumed significance level of α = 0.05). Table 6 shows the average values of selected mechanical properties of the examined types of austenitic ductile iron.

T

Melt A

6,3

16,5

1,3 4,5

71,5

0,5 1,41,46,0

24,0

010

203040

5060

7080

1 2 3 4 5Particle size class

Cap

acity

of g

raph

ite V

v

All the graphite Spheroidal graphitesMelt B

3,28,3

0,7

34,7

53,1

0,2

8,7

0,4 1,6

19,1

0

10

20

30

40

50

60


Cap

acity

of g

raph

ite V

v

All the graphite Spheroidal graphites

Particle size class No Diameter

[um]1 7 2 15 3 30 4 60 5 120

Melt C

3,37,8

70,1

18,0

0,8

34,1

2,00,56,5

0,30

10

203040

5060

7080


Cap

acity

of g

raph

ite V

v

All the graphite Spheroidal graphitesMelt D

2,56,2

44,7 45,8

0,9

17,8

1,10,5

22,0

0,405

101520253035404550


Cap

acity

of g

raph

ite V

v

All the graphite Spheroidal graphites

Fig. 2. Volume fractions of graphite and spheroidal graphite of predetermined size in austenitic ductile iron from

individual melts

Melt A

38,3

29,2

19,4

9,9

2,70,4

2,9

31,534,9

22,3

6,9

1,30

5

1015

20

25

3035

40

45

1 2 3 4 5 6

Shape coefficient class

Num

bers

of g

raph

itese

pera

tion

0

5

1015

20

25

3035

40

45

Cap

acity

of g

raph

itese

pera

tion

Vv

Capacity of graphiteNumbers of graphite

Melt B

33,5

23,7 24,4

12,9

4,60,91,5

24,8

39,4

24,9

8,7

0,70

5

1015

20

25

3035

40

45

1 2 3 4 5 6


Num

bers

of g

raph

itese

pera

tion

0

5

1015

20

25

3035

40

45

Cap

acity

of g

raph

itese

pera

tion

Vv


Melt C

35,8

30,1

22,1

8,9

2,60,51,5

40,0 41,1

14,3

2,3 0,80

510

15

2025

30

3540

45

1 2 3 4 5 6


Num

bers

of g

raph

itese

pera

tion

0

510

15

2025

30

3540

45

Cap

acity

of g

raph

itese

pera

tion

Vv


Melt D

43,5

23,319,0

10,0

3,31,01,6

38,2

29,4

23,5

5,91,4

05

101520253035404550

1 2 3 4 5 6


Num

bers

of g

raph

itese

pera

tion

0

510

15

2025

30

3540

45

Cap

acity

of g

raph

itese

pera

tion

Vv


Fig. 3. Frequency of occurrence and volume fractions of graphite precipitates of predetermined shape in austenitic ductile iron from

individual melts


Table 5. The values of selected stereological parameters obtained for individual melts

Melt Parameter

A B C D Average diameter d[um] 16,6 20,8 20,1 20,3 Confidence level [um] ±0,6 ±1,0 ±0,8 ±1,0

Volume fraction of graphite VBvB [%] 8,3 8,2 8,5 8,1 Volume fraction of spheroids VBvB [%] 2,8 2,5 3,7 3,4

Table 6. Selected mechanical properties of the examined melts of austenitic ductile iron at a temperature of (-196)°C

Melt RBmB [N/mmP

2P] RBp0,2B [N/mmP

2P] AB5B [%]

A 731 ± 14 566 ± 9 6,9 ± 0,1 B 710 ± 9 533 ± 9 19,8 ± 1,0 C 723 ± 2 510 ± 4 28,5± 0,1 D 631 ± 10 510 ± 3 17,7 ± 1,1

5. Discussion of results T

The analysis of different types of cast microstructures revealed the presence of numerous degenerated graphite precipitates determined from standard reference patterns as vermicular, irregular and exploded. The volume fraction of spheroidal graphite in different melts is given in Table 5, where the highest value has been obtained for iron C, containing 25% Ni. At the same time, as follows from histograms in Figure 2, the precipitates of diameter above 30 [um] have prevailed in this case. Comparing these results with the values of mechanical properties determined at (-196)°C, it can be noted that it is the cast iron from melt C that has the highest elongation A

B

5B

combined with satisfactory tensile strength. The drop of tensile strength and elongation in cast iron D can be explained by the high fraction of large graphite precipitates, i.e. of the size above 60 [um]

T

5. Summary T

The conducted studies proved full applicability of the method of automated image analysis in quantitative determination of the graphite parameters in cast iron.

TSince the strongly degenerated forms of graphite appearing in the examined cast iron adversely affect the mechanical and plastic properties of this material, it is advisable to continue studies on a larger number of melts with different content of nickel and inoculant, affecting complete graphite spheroidisation.

References [1] C. Podrzucki: Żeliwo - struktura, właściwości, zastosowanie,

ZG STOP, Kraków 1991. [2] W. Sakwa: Żeliwo, Wyd. „Śląsk”, Katowice 1974. [3] A. Tabor: Odlewnictwo, Politechnika Krakowska, Centrum

Szkolenia i Organizacji Systemów Jakości, Kraków 2007. [4] E. Guzik, D. Kopyciński. Struktura oraz udarność żeliwa

austenitycznego przeznaczonego do pracy w niskich temperaturach. Archiwum Odlewnictwa – Archives of Foundry, PAN Oddz. Katowice, 4, 2004, 12, pp. 115-120.

[5] W. Dziadur, J. Lisak, A. Tabor: Badania korozyjne żeliwa sferoidalnego wysokoniklowego, Odlewnictwo – Nauka i Praktyka, Instytut Odlewnictwa, Zeszyt specjalny 2/2004.

[6] A. Tabor A. Tabor, W. Dziadur, K. Zarębski: Badania właściwości mechanicznych austenitycznego żeliwa sferoidalnego, II Ogólnopolska Konferencja Naukowa „Problemy Jakości Stymulatorem Rozwoju Technologii Bezodpadowych”, Kraków 1999.

[7] A. Tabor: Mechanizm procesu krystalizacji i kształtowania struktury oraz własności austenitycznego żeliwa sferoidalnego, Sprawozdanie projektu badawczego 7T08B 030 13.

[8] O.O. Oluwole, O.E. Olorunniwo, O.O. Ogundare, P.O. Atanda, O.O Oridota: Effect of Magnesium and Calcium as Spheroidizers on the Graphite Morphology in Ductile Cast Iron, Journal of Minerals & Materials Characterization & Engineering, Vol. 6, No.1 (2007), pp 25-37.

[9] K. SHOJI, S. MASAYUKI, S. HARUYOSHI, N. KOKICHI: Formation Mechanism of Chunky Graphite in Heavy Section Spheroidal Graphite Cast Iron, Journal of Japan Foundry Engineering Society, VOL. 72, NO.5, PAGE.311-316 (2000).

[10] J.N. Harvey, G.A. Noble: Inoculation of Cast Irons .An Overview, 55th Indian Foundry Congress 2007.

[11] C.M. Ecob: A Review of Common Metallurgical Defects in Ductile Cast Iron, AFC-9 9th Asian Foundry Congress, Hanoi, Vietnam, October 15-18, 2005.


A R C H I V E S

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F O U N D R Y E N G I N E E R I N G

Published quarterly as the organ of the Foundry Commission of the Polish Academy of Sciences

ISSN (1897-3310) Volume 11

Issue 2/2011 153–156

30/2

The influence of modification and squeeze casting on properties of AlSi11 alloy castings

A. Zyska P

a,P*, Z. Konopka P

aP, M. ŁągiewkaP

aP, M. NadolskiP

a

P

aP Department of Foundry, Technical University of Czestochowa, Armii Krajowej 19, 42-200 Czestochowa, Poland

* Corresponding author’s e-mail: [email protected]

Received 11.04.2011; Approved for print on: 26.04.2011

Abstract The results of structural examinations and tests of mechanical properties of AlSi11 alloy, either gravity or squeeze cast, have been presented. The investigations have been carried out for both the non-modified silumin and the alloy modified with AlSr10 strontium master alloy. The measurements have been carried out for the cast plates of dimensions 200×100×25 mm. It has been found out that the modification combined with squeeze casting provides an advantageous set of strength and plastic properties (RBmB ≈ 270 MPa, AB5B ≈ 16%). The metallographic examination has revealed a significant refinement of both the primary α-phase dendrites and the silicon eutectics, however being dependent on the method of modification and casting. It has been found that the refinement of the primary crystals results from the influence of external pressure exerted on the solidifying casting, while the refinement observed for silicon eutectics is an effect of combined influence of modification and squeeze casting. Keywords: Mechanical properties, Aluminium alloys; Squeeze casting technology; Modification.

1. Introduction The squeeze casting technology belongs to the special

casting methods and is intended for production of high-quality castings, especially made of aluminium alloys. Its advantages, i.e. high dimensional and shape accuracy, good tightness, fine structure, lack of surface defects, low roughness, the large capacity of the process, high output (up to 98% of molten metal), and small machining allowances, make it to be a technology of future. It meets current trends of metal industry, which tend to expand production processes providing for both high quality of products and low production cost, both material and energy savings, and proper manufacturing culture.

The squeeze casting technology combines three the most important and the most popular processes in the processing of aluminium alloy: die casting, pressure casting, and forging. Squeeze casting compares favourably with die casting and pressure casting with respect to the quality of products, and is superior to die casting and forging from the economic point of view. Squeeze casting is applied for production of combustion

engine castings, car wheel discs, casings for compressors and electric engines, and hydraulic elements working under high pressure conditions [1–4].

High mechanical properties of squeezed castings, reaching values which frequently surpass the values obtained for plastic worked elements, results from the fine grain structure arising under the conditions of dynamic solidification under pressure [5-9]. The continuous pressure applied to the solidifying alloy increases the heat transfer coefficient and eliminates the shrinkage gap, diminishing by the same thermal resistance, what in turn increases the supercooling value and results in arising of a large number of crystallization nuclei [1, 6, 11, 12]. The degree of supercooling of the liquid alloy is related to the squeeze temperature. The best effect is achieved by applying pressure at a temperature close to the solidification range [6, 11–13]. Then the maximum supercooling of the alloy occurs and the nucleation rate exhibits the maximum increase. On the contrary, too high squeeze temperature can almost completely nullify the effect of increased pressure. High pressure also prevents arising of gas bubbles in the casting and eliminates shrinkage macro- and micro-porosity, what distinctly increases both


the density and the plasticity of squeezed castings [11–14]. Pressure is a thermodynamic parameter which significantly affects phase transformations. For binary Al-Si alloys, an increase in pressure results in the simultaneous increase of the equilibrium solidification temperature of aluminium and the decrease of the equilibrium solidification temperature of silicon, according to the Clapeyron-Clausius relationship. There occurs a shift of the eutectic point towards higher silicon percentages. During the solidification of squeezed casting, both the rate of growth of the α solid solution dendrites and the volume percentage of this phase in the structure are increased. Simultaneously the silicon-rich regions arise in the liquid metal, so that primary crystals of silicon can originate [3].

Mechanical properties of squeeze cast silumin castings are hence dependent on a series of physical and chemical phenomena taking place during the solidification process, and they can be influenced mainly by the selection of Al-Si alloy type, its modification, and the technological parameters of squeezing. The purpose of the presented investigation has been an assessment of changes in the structure and in the mechanical properties of AlSi11 castings subjected to modification and squeezing.

2. The material and the methods of

examination

The examinations have been carried out for the standardized AlSi11 alloy (PN-EN 1676). Squeeze casting has been manufactured by means of the PHM-250C hydraulic press equipped with a die of cavity dimensions 200×100×50 mm. The die has been heated up to 150°C prior to being poured, and its surface has been covered with a protective insulating and lubricating layer (a solution of colloidal graphite in water). The metal charge has been melted in the PIT 50S/400 induction crucible furnace, then overheated to the temperature of 700°C and drown from the crucible by means of a hand ladle. Each time about 1350 g of alloy has been taken and poured into the lower half of the die. Then the pressing die has been lowered, the die closed, and the squeeze pressure applied. The pressure has affected the solidifying and cooling casting for 50 s. After that time the die has been opened and the casting has been ejected by a set of four ejectors placed in corners of the plate. The castings have been produced either under the pressure of 60 MPa, or by gravity method (without applying pressure) at the mould temperature equal to about 150°C. The subsequent series of castings have been produced of the alloy modified with AlSr10 strontium master alloy. The modifying alloy (0.05% Sr) has been added after overheating the silumin up to 730°C. Then this temperature has been held for a period of 10 minutes in order to homogenize the chemical composition of the alloy. Specimens have been cast of such prepared metal under the same conditions as has been used for the non-modified alloy.

Examination of mechanical properties has been performed for the standardized tensile bars with length-to-diameter ratio of 5:1, according to the PN-91/H-04310 Standard, by means of the ZWICK-1488 servo-hydraulic testing machine. Microstructural observations have been carried out by means of the Nikon Epiphot light microscope for the specimens cut out of the middle parts of the plate castings.

3. The results and the analysis of examinations

The results of measurements concerning the strength properties (RB02B, RBmB) and elongation (AB5B) have been presented in Figures 1 and 2. The performed examinations have unquestionably revealed the superiority of the squeeze casting over the gravity casting method. This is confirmed by the significantly higher RBmB and RB02B values. Modification of the examined alloys causes, in turn, additional increase of mechanical properties, and particularly of plasticity. Having analysed the particular mechanical parameters, one can say that: • the yield point is at the level of 85-95 MPa for gravity cast

items, while the applying of external pressure results in an increase of this parameter up to the value of about 100 MPa. The combined modifying and squeezing leads to the further growth of RB02B, which is enlarged by about 40% with respect to the gravity castings (Fig. 1).

• the tensile strength of AlSi11 alloy castings depends mainly on the casting technology. The squeeze cast items exhibit the tensile strength greater by about 60 MPa than the gravity castings. The squeeze method integrated with modification allows for obtaining the highest strength of the alloy, exceeding 260 MPa (Fig. 1).

• the largest changes in plasticity of the AlSi11 alloy take place as a result of modification. Elongation of the gravity cast specimens made of the modified alloy is twice, and of the modified and squeezed castings is thrice the elongation of the non-modified gravity castings (Fig. 2).

60

80

100

120

140

160

180

200

220

240

260

280

non-modified gravity cast

alloy

non-modified squeeze cast

alloy

modified gravity cast

alloy

modified squeeze cast

alloy

R02

, Rm

, MPa

Fig. 1. The influence of casting conditions on the strength properties of AlSi11 alloy


0

2

4

6

8

10

12

14

16

18

non-modifiedgravity cast

alloy

non-modified squeeze cast

alloy

modified gravity cast

alloy

modified squeeze cast

alloy

Elon

gatio

n A

5, %

Fig. 2. The influence of casting conditions on the elongation AB5B of the AlSi11 alloy

The characteristic feature of a casting solidifying under

pressure is the refinement of its structure, which results in the strengthening of the alloy. The structure of AlSi11 alloy consists of two phases. First of them is the plastic matrix of α(Al) solid solution, and the second one is constituted by hard and brittle silicon crystals. The structure of the non-modified gravity castings is characterised by relatively large dendrites of α phase on a background of the lamellar silicon eutectics (Fig. 3a). After the strontium master alloy had been added to the processed metal, the eutectics has been effectively modified to the fibrous one (Fig. 3b). Further structural changes are related to the pressure which influence the solidifying casting.

a)

b)

c)

d)

Fig. 3. Microstructure of AlSi11 alloy: a) non-modified, gravity cast alloy, b) non-modified squeeze cast alloy, c) modified gravity

cast alloy, d) modified, squeeze cast alloy


References Squeeze casting of the non-modified AlSi11 alloy has resulted in size reduction of α-phase crystals and in the refinement of the silicon eutectics, though the distances between silicon lamellae are much greater than for the modified alloy (Fig. 3c). Such changes in the alloy structure are related to the increased rate of heat extraction by the metal mould. Due to the applying of external force, the shrinkage gap occurring during the solidification process between a casting and the mould arises much later than it does for the case of the gravity die casting solidification. This means significantly less width of the gap and more intensive heat extraction by the die. Research works presented in references [Ref. 3, 15] show that squeeze casting shortens the solidification period of a casting by 1,5 up to 5 times. The combined influence of modification and external pressure has permitted for obtaining the most refined structure. Modification has assured for achieving the eutectics with very small interfacial distance, while the influence of pressure has caused the refinement of the α-phase dendrites (Fig. 3d). This refinement of structure has been accompanied by the enhancement of the mechanical properties, and first of all of plasticity.

[1] J. Batysev, Crystallisation of metals and alloys under

pressure, Metallurgy, Moscow (1977) (in Russian). [2] M. Perzyk, S. Waszkiewicz, M. Kaczorowski, A. Jopkiewicz,

Foundry Engineering , WNT, Warsaw (2000) (in Polish). [3] J. Sobczak, Z. Lech, Theoretical and practical aspects of

squeeze casting of non-ferrous metals, Foundry Review (1991) (in Polish).

[4] J. Sobczak, Squeeze casting of aluminium alloys, Ed. Foundry Research Institute, Cracow (1988).

[5] S.W. Kim, D.Y. Kim, W.G. Kim, K.D. Woo, The study on characteristics of heat treatment of the direct squeeze cast 7075 wrought Al alloy, Materials Science and Engineering, A304–306 (2001) 721–726.

[6] L.J. Yang, The effect of casting temperature on the properties of squeeze cast aluminium and zinc alloys, Journal of Materials Processing Technology, vol. 140 (2003) 391–396.

[7] T. M. Yue, Squeeze casting of high-strength aluminium wrought alloy AA7010, Journal of Materials Processing Technology, vol. 66 (1997) 179–185.

[8] S. M. Skolianos, G. Kiourtsidis, T. Xatzifotiou, Effect of applied pressure on the microstructure and mechanical properties of squeeze-cast aluminum AA6061 alloy, Materials Science and Engineering, vol. A231 (1997) 17–24.

4. Conclusions 1. Squeezing of castings generates first of all an increase in the

strength properties, while modification influences principally the plasticity of the AlSi11 alloy. The combined application of both these treatment types allows for manufacturing of castings which exhibit high mechanical properties: RBmB ≈ 270 MPa, AB5B ≈ 16%.

[9] M.T. Abou El-khair, Microstructure characterization and tensile properties of squeeze-cast AlSiMg alloys, Materials Letters, vol. 59 (2005) 894– 900.

[10] S.W. Youn, C.G. Kang, P.K. Seo, Thermal fluid / solidification analysis of automobile part by horizontal squeeze casting process and experimental evaluation, Journal of Materials Processing Technology, 146 (2004) 294–302.

2. The dynamic crystallization of the alloy under pressure results in the refinement of both the primary α-phase dendrites and the silicon eutectics, although the distances between silicon lamellae are much greater than for the modified alloy.

[11] B. Chaterje, A.A. Das, The British Foundryman, vol. 14 (1973) 118.

[12] M. Hajdasz, Barocrystallization of metal alloys, Archives of Machine Construction Technologies, vol. 12 (1993) 45 (in Polish).

3. Integration of squeeze casting method and the modifying treatment permits for obtaining the most advantageous structure of AlSi11 alloy, consisting of fine crystals of the α-phase and the fibrous silicon eutectics. [13] R.F. Lynch, Squeeze Casting, Material Delaware Valley

Charter, ASM, Doehler-JarvisNL Industries, Toledo (1973). [14] M. Hajdasz, Squeeze casting, Foundry Review, vol. 43,

No. 4 (1993) 110 (in Polish). [15] A. Zyska, Z. Konopka, M. Łągiewka, The solidification of

squeeze cast AlCu4Ti alloy. Archives of Foundry Engineering vol. 7, issue 4 (2007) s. 193-196.


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