Study of CVD and PVD Coatings for Turbomachinery Life Predictions

摘要

The design and development of high performance turbomachinery operating in a particulate flow environment requires a thorough knowledge of the fundamental phenomena associated with solid particulate flows. Because of the serious consequences of turbomachinery erosion on performance and life, it is important to have reliable methods for predicting erosion when solid particles are ingested. Over the past twenty-five years, the University of Cincinnati's Turbomachinery Erosion Laboratory has conducted many of these studies, which are essential to predicting blade surface erosion intensity and patterns. This paper will present experimental compressor and turbine blade erosion results for coated blade materials due to high velocity solid particle impacts at ambient and elevated temperatures. The tests were conducted in an erosion wind tunnel, which simulates the aerodynamic effects of varying conditions on the blades. Coated turbine blades were tested in the hot erosion wind tunnel and compressor blades were tested in the cold cascade wind tunnel. The experimental study used turbine blades coated with rhodium platinum aluminum (RT22B), titanium carbide (TiC) and titanium nitride (TiN) on substrates INCO718 and M246. Two first stage compressor blades, one coated with PVD nitrite and one uncoated,were also studied. This investigation showed that the tested CVD and PVD nitride coatings provided highly effective erosion protection for turbomachinery blades. The extended blade life predicted in this study was confirmed with newly built commercial compressors utilizing the above coatings and substrates.