Project Title:

Nondestructive Characterization of Thermal Spray Coating Porosity and Thickness

  94-1	04.06	5552

  Nondestructive Characterization of Thermal Spray Coating Porosity 
  and Thickness

Abstract:

The Meandering Winding Magnetometer (MWM) is a new type of eddy
current sensor designed specifically for estimation of material 
properties. The innovation proposed here is to develop and 
demonstrate an MWM measurement system for characterization of 
thickness and porosity for metallic thermal spray coatings. The 
Phase I objectives are to (1) demonstrate the ability of the MWM to 
measure thickness for metallic thermal spray coatings with 
different levels of porosity, on metallic substrates, (2) determine 
the relationship between the "effective electrical properties" 
estimated using the MWM and the level of porosity in the thermal 
spray coating, (3) investigate the range of properties and 
dimensions for metallic, intermetallic and superalloy coatings and 
substrates that can be characterized using the MWM approach, and 
(4) determine the scale-up potential, path to commercialization, 
and anticipated system cost for an MWM inspection system. The 
proposed effort will include demonstration of thermal spray coating 
characterization on samples fabricated by Oak Ridge National 
Laboratories and correlation with destructive measurements made by 
University of Tennessee. The anticipated result of this Phase I 
effort is the demonstration of a quantitative porosity and 
thickness measurement suitable for real time process and quality 
control for thermal spray deposition processes.

The extension of the MWM measurement system capability to include 
heterogeneous media such as porous coatings will provide wide 
ranging commercial applications from aerospace, automotive and 
materials processing to electronics. One specific near-term 
application is characterization of oxidation protection coatings 
for combustion turbine blades. This application in itself could 
provide a significant service and product demand.

Key Words

JENTEK Sensors, Inc.
1616 Soldiers Field Road
Boston, MA 02135