Effects of Vibration and Salts Treatments on Aluminium Alloy Properties Used in Mould Manufacture

2015 ◽  
Vol 1128 ◽  
pp. 58-63
Author(s):  
Laurenţiu Ardeleanu ◽  
Constantin Bratu ◽  
Ioan Mărginean

Metallic mould properties are influenced by the technological process used on casting. The mechanical properties of aluminium castings can be affected by dissolved gases, heterogeneous impurities or shrinkage remaining in casting after solidification. Dissolved gases and oxide inclusions in aluminium all have a deleterious effect on casting quality. The treatment of molten aluminium using vibrations and salts was found to be highly efficient in refining the microstructure of the alloy. The main objective of the paper is to understand the effects of vibrations and salts treatment on the final microstructure and changes that take place and influences aluminium alloy properties used in mould manufacture. The microstructural changes have a great significance in improving the properties of aluminium alloy castings. Understanding this effects and the modification mechanism can undoubtedly be of great significance for improving casting quality. Fluxes based on a KCl-NaCl mixture may be used to cover and protect the metal from oxidation. Most fluxes are based on a mixture of KCl and NaCl, which forms at low-temperature (665 °C) eutectic.

2013 ◽  
Vol 765 ◽  
pp. 225-229 ◽  
Author(s):  
Yang Yue ◽  
William D. Griffiths ◽  
Nick R. Green

Entrainment defects such as double oxide films and entrapped bubbles occur frequently in aluminium alloy castings during the mould-filling process, and are very detrimental to both mechanical properties, and reproducibility of casting properties. In this study a modelling algorithm was used to predict the formation and distribution of entrainment defects in Al-Si-Mg alloy castings. The tensile strength of cast test bars was compared with either the number of defects, or the defect concentration within the bars obtained from the simulation. A general relationship between the mechanical strength of the cast test bars and the quantity of estimated defects was apparent.


2015 ◽  
Vol 15 (4) ◽  
pp. 124-128 ◽  
Author(s):  
J. Roučka ◽  
J. Hotař

Abstract At thermal junctions of aluminium alloy castings and at points where risering proves to be difficult there appear internal or external shrinkages, which are both functionally and aesthetically inadmissible. Applying the Probat Fluss Mikro 100 agent, which is based on nano-oxides of aluminium, results in the appearance of a large amount of fine microscopic pores, which compensate for the shrinking of metal. Experimental tests with gravity die casting of AlSi8Cu3 and AlSi10Mg alloys have confirmed that the effect of the agent can be of advantage in foundry practice, leading to the production of castings without local concentrations of defects and without the appearance of shrinkages and macroscopic gas pores. Also, beneficial effect on the mechanical properties of the metal has been observed.


2010 ◽  
Vol 5 (2) ◽  
pp. 55-63
Author(s):  
G. Raghu Babu ◽  
◽  
K.G.K. Murti ◽  
G. Ranga Janardhana ◽  
◽  
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