Ultrasonic method to determine gas porosity in aluminum alloy castings: Theory and experiment

Journal Article · Wed Jan 15 00:00:00 EST 1986 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.336689· OSTI ID:6346487

Adler, L; Rose, J H; Mobley, C

The characterization of porosity in solids using the frequency dependence of the ultrasonic attenuation is discussed both from the theoretical and experimental viewpoint. The major thrust of our work is the determination of the volume fraction and size of the voids for the case of dilute porosity (<6%) in structural materials. An aluminum alloy (A357) was chosen for study due to its economic importance in large-scale casting and the particular suitability of aluminum for this type of study. Following recent papers the attenuation is described by an independent scatterer model for spherical voids. Numerical results are presented in a form suitable for use with a range of materials. A method for determining the volume fraction and pore size is given. Specific tabular results are given for stainless steel, IN-100, Ti, Si3N4, as well as aluminum. Figures of merit which partially describe those situations in which the method is usable are also presented. In the experimental work a digitized spectrum analysis system was used to measure the frequency dependence of the attenuation coefficient in A357 aluminum cast alloys. In the cast materials the average pore size was in the order of 100 m and the pore concentration varied from essentially 0 to 6%. It was found that experimental measurement of the attenuation could be fit by the theoretical model. The resulting parameters yield a good estimate of the pore volume fraction.

• Research Organization: Department of Welding Engineering, The Ohio State University, Columbus, Ohio 43210
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6346487
• Journal Information: J. Appl. Phys.; (United States), Vol. 59:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ACOUSTIC TESTING
CASTING
NONDESTRUCTIVE TESTING
POROSITY
MEASURING METHODS
SILICON NITRIDES
STAINLESS STEELS
TITANIUM ALLOYS
ATTENUATION
CAVITIES
CERAMICS
CRYSTAL STRUCTURE
ALLOYS
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
ELEMENTS
FABRICATION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS TESTING
METALS
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
STEELS
TESTING
360104* - Metals &amp; Alloys- Physical Properties