Porosity of Castings Produced by the Vacuum Assisted Pressure Die Casting Method

• Autorzy: Zyska A. , Konopka Z. , Łągiewka M. , Nadolski M.

Identyfikatory

DOI

10.1515/afe-2015-0023

• Języki publikacji: EN

Abstrakty

EN

The paper presents the results of investigations concerning the influence of negative (relative) pressure in the die cavity of high pressure die casting machine on the porosity of castings made of AlSi9Cu3 alloy. Examinations were carried out for the VertaCast cold chamber vertical pressure die casting machine equipped with a vacuum system. Experiments were performed for three values of the applied gauge pressure: -0.3 bar, -0.5 bar, and -0.7 bar, at constant values of other technological parameters, selected during the formerly carried initial experiments. Porosity of castings was assessed on the basis of microstructure observation and the density measurements performed by the method of hydrostatic weighing. The performed investigation allowed to find out that – for the examined pressure range – the porosity of castings decreases linearly with an increase in the absolute value of negative pressure applied to the die cavity. The negative pressure value of -0.7 bar allows to produce castings exhibiting porosity value less than 1%. Large blowholes arisen probably by occlusion of gaseous phase during the injection of metal into the die cavity, were found in castings produced at the negative pressure value of -0.3 bar. These blowholes are placed mostly in regions of local thermal centres and often accompanied by the discontinuities in the form of interdendritic shrinkage micro-porosity. It was concluded that the high quality AlSi9Cu3 alloy castings able to work in elevated temperatures can be achieved for the absolute value of the negative pressure applied to the die cavity greater than 0.5 bar at the applied set of other parameters of pressure die casting machine work.

Słowa kluczowe

EN

innovative foundry technology; aluminium alloy; vacuum assisted pressure; die casting; casting defect; porosity

PL

innowacyjna technologia odlewnicza; stop aluminium; formowanie podciśnieniowe; odlewanie ciśnieniowe; wada odlewu; porowatość

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2015
• Tom: Vol. 15, iss. 1
• Strony: 125--130
• Opis fizyczny: Bibliogr. 16 poz., rys., tab., wykr.

Twórcy

autor

Zyska A.

• Department of Foundry, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Konopka Z.

• Department of Foundry, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Łągiewka M.

• Department of Foundry, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Nadolski M.

• Department of Foundry, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland

Bibliografia

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