The application of glow discharge optical emission spectroscopy to the study of thermal barrier and environmental coatings

Glow discharge optical emission spectroscopy (GDOES) has been developed to investigate thermal barrier and environmental coatings. Qualitative analysis of thermal barrier and environmental coating has shown that this technique exhibits considerable potential. Work has been conducted to quantify the results. This involved the preparation of well documented calibration standards for alloy systems containing up to fifteen elements. The advantages of the technique lies in its ability to analyze up to 44 elements ranging from hydrogen to uranium with a lateral resolution in the order of tens of nanometers. Results will be presented identifying the elemental distribution across the coating interface which will be compared with results from quantitative analysis conducted using scanning electron microscopy and X-ray fluorescence technique. The results will be discussed in terms of the GDOES technique sensitivity/limitations and elemental interference encountered and possible optimisation in developing this technique for understanding degradation mechanisms involved in thermal barrier and environmental coatings.