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1

Soldification curves structure of heterophase composite

Dolata-Grosz A., Dyzia M., Śleziona J.

Archives of Materials Science and Engineering

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2008

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Vol. 29, nr 1

10-15

EN

Purpose: This paper presents results of solidification tests for homo- and heterophase composites. Researches concerned influence of reinforcement particle for solidification process of composite materials . Curves of solidification composite reinforced with (Al2O3) and heterophase reinforcement (mixture of Al2O3 particles +glassy carbon) were compared with aluminium alloy matrix (AlSi12CuNiMg2). Based casting spiral test the castability of composite were put to the test. Also macro and microstructure ingots after solidification on equal thermal conditions were presented. Design/methodology/approach: Solidification process was recorded with 0.4 sec. period by analog-digital converter connected to PC. Temperature was controlled by K thermocouple (NiCr-Ni) installed in standardized thermoelectric cup core QC4080. That equipment made possible to realised solidification tests on the equal thermal conditions. The castability was tested on standard spiral duct formed at self hardening phosphate mould. Findings: Results of researches confirm influence of glassy carbon on solidification of composite suspension. Compared to aluminium oxide particles (Al2O3) glassy carbon accelerate solidification process of composite material. Probably, it results from disparate properties of glassy carbon. Practical implications: Glassy carbon particles change characteristics of composite crystallization and decrease shrinkage of the casting. Moreover application of mixture of Al2O3 and glassy carbon as heterophase reinforcement allows to segregation and sedimentation particles in the matrix and it guides in results of solidification to gradient structure of composite material. Originality/value: Employment of heterophase reinforcement allows to get segregation and sedimentation in the matrix, which results in the occurrence of a gradient structure.

2

Solidification and structure of heterophase composite

Dolata-Grosz A., Dyzia M., Śleziona J.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

103-106

EN

In this paper, the structure and solidification curves are presented for a homo- and heterophase composite. The results of research on the solidification process are compared for the applied aluminium alloy matrix (AlSi12CuNiMg2) and for composites containing one type of particles (Al2O3) and heterophase reinforcement (mixture of Al2O3 particles + glassy carbon - Cg). Design/methodology/approach: The course of the solidification process was recorded by means of a system which enabled continuous control and measurement of the metal temperature during solidification of the composite suspension. The system was equipped with a thermoelectric cup core QC4080, with an incorporated thermocouple of K type (NiCr-Ni). The application of disposable thermoelectric cup cores of identical heat abstraction coefficient and known, standardized dimensions, ensured identical conditions and rate of heat abstraction during the cooling of the castings. Findings: The research has shown, glassy carbon particles have an influence on both temperature change and the time of composite castings solidification. The changes results, first of all, from disparate physical properties of the glassy carbon particles used (thermal conductivity, mass density), compared to aluminium oxide particles (Al2O3). Practical implications: Glassy carbon particles decrease shrinkage of the casting and change the nature of its crystallization. Originality/value: Employment of heterophase reinforcement allows to get segregation and sedimentation in the matrix, which results in the occurrence of a gradient structure.

3

Solidification analysis of AMMCs with ceramic particles

Dolata-Grosz A., Dyzia M., Śleziona J.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 7

401-404

EN

Purpose: In the research work the result of the reinforcement displacement and solidification analysis for aluminium cast composites with ceramic particles have been presented. The results of research on the solidification process are compared for the applied aluminium matrix alloy (AlSi12CuNiMg2), for composites containing glass carbon particles (Cg) and heterophase reinforcement (mixture of silicon carbide (SiC)+glass carbon particles (Cg)). Design/methodology/approach: The course of the solidification process was recorded by means of a system which enabled continuous control and measurement of the metal temperature during solidification of the composite suspension. The system was equipped with a thermoelectric cup core QC4080, with an incorporated thermocouple of K type (NiCr-Ni). The application of disposable thermoelectric cup cores of identical heat abstraction coefficient and known, standardized dimensions, ensured identical conditions and rate of heat abstraction during the cooling of the castings. The structure analysis for composite casts was performed by means of optical and scanning microscopy. Findings: The research has shown, that ceramic particles have an influence on temperature change and the time of aluminium matrix alloy solidification. The changes results, first of all, from disparate physical properties of the glassy carbon particles and silicon carbide particles used (thermal conductivity, mass density), compared to aluminium matrix alloy. Practical implications: Ceramic particles decrease shrinkage of the casting and change the nature of its crystallization. Originality/value: Employment of glass carbon particles for matrix reinforcement allows to get flotation in the aluminium alloy. Employment of heterophase reinforcement (glass carbon and silicon carbide particles) allows to get segregation of particles: flotation as well as sedimentation in the matrix, which results in the occurrence of a layered structure.

4

Analiza procesu krzepnięcia kompozytu heterofazowego

Dolata-Grosz A., Dyzia M., Śleziona J., Myalski J.

Archiwum Odlewnictwa

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2006

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R. 6, nr 22

145-151

PL

Badania dotyczące krystalizacji i krzepnięcia odlewów to ostatni etap wytwarzania zawiesin kompozytowych. Opis i poznanie zjawisk towarzyszących tym procesom pozwala na kształtowanie zróżnicowanej struktury wytwarzanych materiałów, od której ściśle zależą właściwości finalnego wyrobu. W pracy przedstawiono i porównano wyniki badań procesu krzepnięcia zarówno dla zastosowanej osnowy ze stopu aluminium (AK12Mg2), jak i kompozytów zawierających jeden rodzaj cząstek (Al[2]O[3]) oraz zbrojenie heterofazowe (mieszanina cząstek Al[2]O[3] + węgiel szklisty).

EN

Research concerning crystallization and solidification of cast are last stage in composite suspension producing. Description and knowledge of phenomena accompanying these processes anows to forming of diversity structure of fabricated material, on which specificity depend strictly of final cast properties. In this paper results of solidification process of research of aluminum metal matrix alloy (AKI2Mg2), as well as of composites including homophase(Al[2]O[3]) and heterophase (Al[2]O[3]) + glass carbon) reinforcement were presented and compared.