Real-time X-ray Radiography and Computational Modeling of Shrinkage Porosity Formation in Aluminum Alloy Castings

Abstract Commercial software packages enable the thermal environment of shaped castings to be determined provided the boundary conditions are well understood. Criteria functions (CF’s) based on the thermal environment provide a means for estimating shrinkage porosity within a casting. However, the CF’s do not account for gas driven porosity forming within the casting. This paper reviews the CF’s and additional approaches to account for hydrogen evolution in aluminum-copper and aluminum-silicon alloys.

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Study of Solidus Velocity on Porosity Formation in A201 Aluminum Alloy Castings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.705.223 ◽

2013 ◽

Vol 705 ◽

pp. 223-227

Author(s):

Y.S. Kuo

Keyword(s):

Aluminum Alloy ◽

Silica Sand ◽

Systematic Change ◽

Porosity Formation ◽

Alloy Plate ◽

Aluminum Alloy Plate ◽

Alloy Castings ◽

Different Thickness

The purpose of the present study was to discuss the effects of solidus velocity on porosity formation of A201 aluminum alloy plate castings. With systematic change in the riser size, together with variation of thickness and length, were cast in sand molds. The sand molds with end chill for the plate castings were made of 100% silica sand. The porosity content of A201 aluminum alloy was affected by the solidus velocity in this study. The correlation between porosity content and solidus velocity is found to be split into 2 bands, each being associated with one of the different thickness of plate castings.

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Study of Solidification Time and Solidus Velocity on Porosity Formation in High Strength Aluminum Alloy Castings

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.575.442 ◽

2014 ◽

Vol 575 ◽

pp. 442-445

Author(s):

Yeong Sant Kuo

Keyword(s):

Aluminum Alloy ◽

High Strength ◽

Solidification Time ◽

Local Solidification Time ◽

Silica Sand ◽

Systematic Change ◽

Porosity Formation ◽

Alloy Plate ◽

High Strength Aluminum Alloy ◽

Alloy Castings

The purpose of the present study was to discuss the effects of local solidification time and solidus velocity on porosity formation in high strength aluminum alloy casting. With systematic change in the riser size, together with variation of thickness and length, A201 aluminum alloys were cast in 100% silica sand molds. The porosity content of A201 aluminum alloy was affected by the local solidification time and solidus velocity in this study. The correlation between porosity content and solidification time is found to be split into 2 bands, each being associated with one of the two thicknesses of plate castings. The longer the solidification time, the more the porosity content was measured in the A201 aluminum alloy plate casting. And the faster the solidus velocity, the more the porosity content in this study. The porosity content of A201 aluminum alloy was influenced by both of solidification time and solidus velocity at same time in this study. Basically, shorter local solidification time with slow solidus velocity seems get lower porosity content in A201 aluminum alloy castings.

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Defects in Aluminum Alloy Castings

Encyclopedia of Aluminum and Its Alloys ◽

10.1201/9781351045636-140000253 ◽

2019 ◽

Author(s):

John Campbell

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Hydrogen Embrittlement ◽

Stress Corrosion Cracking ◽

Tensile Elongation ◽

Shrinkage Porosity ◽

Corrosion Cracking ◽

The Other ◽

Al Alloy ◽

Alloy Castings

Most of the major defects in Al alloy castings are the result of entrainment processes. The entrainment of the surface of the liquid creates bifilm defects, and the entrainment of air creates bubbles and bubble trails. Occasionally the entrainment of foreign inclusions, such as sand inclusions, can also be a problem. Bifilms form the initiators of gas porosity, shrinkage porosity, hot tears, and cracks. Since bifilms can be controlled by improved melting and casting techniques, all these defects are controllable. In addition, bifilms control the mechanical properties of castings, particularly tensile elongation, toughness, and fatigue. The other important effects caused by bifilms such as invasive corrosion behavior including pitting, stress corrosion cracking, and possibly hydrogen embrittlement, are beyond the scope of this review.

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