International Journal of Materials Engineering and Technology
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Abstract: Various degassing methods have been used to reduce
porosity defects in aluminum alloy casting, but until now, these efforts have
not produced optimum results. Focus of this research is the effect of copper and
air pressure control in minimizing hydrogen solubility in a duralumin melt. For
a number of experiments, copper was added in variations of 2.5, 3.0, 3.5, 4.0,
4.5 wt% and the vacuuming process was adjusted continuously in variations of 76,
50 and 40 cmHg during melting process to less than 10 cmHg during the
solidifying process. Permanent mold was heated to 300°C before pouring the
duralumin melt. The experimental additions of copper from 2.5-4.0 wt% Cu, and
4.0-4.5 wt% of Cu result in an apparent increase and a decrease in quantitative
porosity, respectively. An apparently decreases quantitative porosity. The
morphology test (image) with optical and scanning electron microscopy shows gas
porosity. Phases of a-Al, b-Cu, are
apparent in signal of the X-ray diffraction test.
Keywords and phrases: duralumin, porosity, solidification, vacuum, permanent mold.
