Surface flaw inspection for metal material.

Eddy Current System for Material Inspection and Flaw Visualization

Eddy current methods have been successfully used in a variety of non-destructive evaluation applications including detection of cracks, measurements of material thickness, determining metal thinning due to corrosion, measurements of coating thickness, determining electrical conductivity, identification of materials, and detection of corrosion in heat exchanger tubes. This paper describes the de...

Automated metal surface inspection through machine vision

This paper proposes a method for automated visual inspection of metal surfaces. Firstly, the modified grey-level co-occurrence matrices of metal images are used to access the information of metal surfaces. Secondly, the difference moment and the entropy of the greylevel co-occurrence matrices are extracted as the features of the metal surfaces. Finally, the features of the inspecting images are...

Groundwork for Rail Flaw Detection Using Ultrasonic Phased Array Inspection

An apparent increase in the detectability of certain flaws results when the ultrasonic inspection beam was oriented off the longitudinal axis of railroad rail. Here, artificial reflectors were used to better define the extent of material "seen" by inspection beams, and determine how surface curvature might affect the inspection. Presumably, such information could be useful for suggesting optimu...

Free-Form Surface Matching for Surface Inspection

Remote photoacoustic imaging for material inspection

We report on (to our knowledge) the first remote contactless photoacoustic imaging with short excitation pulses on semitransparent solid polymer samples for material inspection. In this work solid semitransparent samples are excited with pulses from a short pulse laser. The local absorption of the electromagnetic radiation leads to generation of broadband ultrasonic waves. Ultrasonic waves arri...