ENHANCING THE ADHESION STRENGTH OF COLD GAS DYNAMIC SPRAYED COATINGS BY PREPARING THE SUBSTRATES WITH THE HIGH-FREQUENCY PULSED WATERJET

摘要

It is known that surface preparation can affect performance of thermal spray coatings more than any other variables. The objective of this study is to gain an understanding of the effect of different surface preparations on the adhesion strength of coatings applied by the cold gas dynamic spraying technique. Preparation methods under consideration are: polishing, grit blasting and high-frequency pulsed waterjet. The results demonstrate that adhesion strength of the grit blasted substrates is lower than the one achieved with the pulsed waterjet substrates. Furthermore, the results indicate that pulsed water jet provides a very simple method to control surface roughness by simply varying the standoff distance.