Development of Compact Plasma Sprayed Coatings for High Temperature Solar Tower Receivers

The current developments in concentrating solar power are focused in the third generation. Increase the working temperature of the plants is the main objective for this new generation. For this new condition, alternative materials for the receivers must be explored. In this work, a nickel alloy coating has been fabricated using a compact plasma spray system to be used on the receiver. This thermal spray system could be used for in-situ maintenance and overhaul as it is portable. Then the coatings have been exposed at high temperature of 800 ºC, as expected in the third generation, during different exposure times. The evolution of the coating solar absorptivity and adherence have been studied over the selected exposure times. A maximum value of solar absorptivity 0.93 was reported for the longer exposure time studied. The adherence increment was remarkable reaching a value of about 57 MPa. These results show that these coatings could represent a durable alternative while the solar absorptivity maintains high values.