Non-destructive Sheet Metal Inspection

National Laboratory: 
Pacific Northwest National Laboratory
Characterization Class: 
Non-destructive examination
Processing/Manufacturing Class: 
Shaping and forming
Description: 

This capability contains eddy current electrical conductivity and flaw detector and ultrasound flaw, corrosion, and thickness detect sensors. Before or after sheet metal forming and heat treatment, grain size and precipitated phase sizes and quantities change. This non-destructive test can easily estimate the thickness, flaw, and soundness of heat treatment.

Capability Bounds: 

Eddy current has 60-kHz or 480-kHz frequency and digital conductivity display from 0.9% to 110% IACS or 0.5 to 64 Ms/m. Accuracy is within ±0.5% IACS from 0.9% to 65% IACS and within ±1.0% in values over 62%. Each heat treatment has a special trend of electrical conductivity that varies with its microstructure, before and after treatment. Ultrasound thickness gauge has a thickness detection range from 0.080 to 635 mm, depending on the material, transducer surface conditions, temperature, and selected configuration. Material velocity range is from 0.508 to 13.998 mm/µs, and frequency range is from 2.0 to 30 MHz.

Unique Aspects: 

Correlating with hardness and tensile tests, the soundness of heat treatment and physical properties can be easily measured. In situ measurement also is possible. Depending on size, shape, and materials, the approach method will need to be changed or modified (can be done at Pacific Northwest National Laboratory).

Availability: 

Facilities are available for both government and private (proprietary) project work.

Single Point of Contact: 

Name: Jung Pyung Choi
Email: jungpyung.choi@pnnl.gov
Phone: 509-375-2120

References: 
  1. Jung Pyung Choi, Aashish Rohatgi, Mark T. Smith, and Curt Lavender: “Process Development for Stamping A-Pillar Covers with Aluminum”, Light Metals 2015, pp. 197-201
  2. Ramprashad Prabhakaran, Jung Pyung Choi, Elizabeth Stephens, David Catalini, Curt Lavender, and Aashish Rohatgi: “Mechanical Characterization and Corrosion Testing of X608 Al Alloy”, Light Metals 2016 (will printed)
Supporting Document(s):