Complies with Boeing Specification BAC-5651 BAC 5651 Eddy Current Electrical Conductivity Inspection

Conductivity Testing:

The electrical conductivity measurement is employed for the production, processing or inspection of finished goods.

The electrical conductivity measurement is an important quality assurance component in the manufacture, maintenance or repair of airplanes.

The electrical conductivity is an important material property that not only informs about how well a metal conducts electrical current but also provides information about its composition, microstructure or mechanical properties.

Electrical conductivity is a property of metals that can be used to sort various alloys, or give an indication of the heat treat condition of an alloy. In materials to be used for electrical conductors, the electrical conductivity is a vital direct indication of the material's ability to perform efficiently.

Heat treatment affects both the hardness and electrical conductivity of most aluminum alloys. Although the primary purpose behind heat treatment is to control hardness of the alloy, measuring the hardness with a contact tester is slow, can be difficult on large or complex parts, and may produce undesirable surface blemishes. Eddy current conductivity testing provides a rapid portable indirect measurement of hardness, provided the alloy is known.

Applications:

• Directly measure resistivity of metals and alloys on aircraft structures.
• Measurement of the electrical conductivity of all non-magnetic metals, even stainless steel.
• Measurement of the hardness and strength of heat-treated materials, e.g., aluminum alloys; inspection for heat damage.
• Directly measure resistivity of metals and alloys on aircraft structures.
• Detect heat damage caused by friction, fire, or lightning strikes.
• Detect cold deformation.
• Detect thickness variation caused by wear, corrosion, or manufacturing variations on materials such as aircraft skins.
• Measure a nonconductive coating, such as paint.
• Provide conductivity test results in precise, digital readings.
• Determination of the degree of purity.
• Scrap metal sorting.
• Verifying the homogeneity of alloys.
• Measurement of the hardness and strength of heat-treated materials, e.g., aluminum alloys; inspection for heat damage. Measurement of the phosphor content in copper.

Conductivity Testing or Sorting:

One of the major applications of eddy current testing is the measurement of conductivity. This application is possible since most materials have a unique conductivity value determined by their chemical composition, and the processing and method of manufacture. Standard conductivity has been defined by the International Electrochemical Commission in terms of the amount of resistance to be found in a specific grade of high purity copper when measured at 20~C (68~F). This resistance has been arbitrarily designated as 100% International Annealed Copper Standard (IACS) conductivity. Based on this information, by knowing the IACS of a particular material or by using a calibration standard, material sorting is possible.