@inproceedings{6baefab9696e48ca936204785533971e,
title = "Novel methods for crack detection in green and sintered parts",
abstract = "Crack detection in unsintered, or green, powder metal parts has been of interest for decades with no commercial solution available. Traditional ultrasonic techniques using liquid couplant cannot be used with green parts since residue left behind from the couplant will degrade the final quality of the sintered part. In this paper, two couplant free techniques are presented for the inspection of green and sintered parts. The surface wave mediator technique uses point contact with a part to induce and receive Rayleigh surface waves which are sensitive to surface breaking cracks and density variations. The mediator tip can be shaped to effectively inspect both flat and curved geometries such as boreholes. Feasibility studies performed using ultrasonic electromagnetic acoustic transducers (EMATs) on both green and sintered parts have been successful in impinging ultrasonic energy into the parts for defect detection. Due to the low aspect ratio of many powder metal parts, ultrasonic guided waves can provide full part characterization. Shear horizontal waves were used to inspect the flange of a transmission part and torsional waves have been used to inspect the welded region of a sintered porous filter.",
author = "Zhu Yun and Hauck, {Eric T.} and Rose, {Joseph L.}",
year = "2006",
month = mar,
day = "6",
doi = "10.1063/1.2184701",
language = "English (US)",
isbn = "0735403120",
series = "AIP Conference Proceedings",
pages = "1507--1514",
booktitle = "Review of Progress in Quantitative Nondestructive Evaluation",
note = "Review of Progress in Quantitative Nondestructive ; Conference date: 31-07-2005 Through 05-08-2005",
}