The high temperature erosion of commercial thermally sprayed metallic and cermet coatings by solid particles

Because of the serious consequences of turbomachinery erosion on their performance and life, it is important to have reliable methods for predicting their erosion when solid particles are ingested with the incoming flow. This is a very challenging problem since turbomachinery erosion is affected by many factors such as blade passage geometry, blade row location, rotational speed flow conditions, blade material and particles’ characteristics. Several studies which are essential to predicting blade surface erosion intensity and pattern, have been conducted at the University of Cincinnati’s Propulsion Laboratory over the past twenty-five years. This paper describes only some of the work done on erosion testing at high temperatures and velocities for different materials and coatings. The testing has been performed with a special high temperature erosion wind tunnel which simulates the aerodynamic conditions on the blades. The coated substrates reveal one order of magnitude less wear compared to some commercial non-CVD coatings on the same alloys. This study demonstrates that some coatings provide an excellent erosion resistance to INCO 718, LNCO 738, MAR-246, X-40 and Tungsten Carbide.

Download Full-text

High-Temperature Erosion and Corrosion Measurement of Thermally Sprayed Materials

Advanced Engineering Materials ◽

10.1002/adem.200300227 ◽

2003 ◽

Vol 5 (4) ◽

pp. 213-217 ◽

Cited By ~ 6

Author(s):

S.C. Cha ◽

P. Wölpert

Keyword(s):

High Temperature ◽

High Temperature Erosion ◽

Thermally Sprayed

Download Full-text

High Temperature Erosion-Oxidation Behavior of Thermally Sprayed NiCr Based Alloy and Cermets Coatings

Materials Science Forum ◽

10.4028/www.scientific.net/msf.530-531.117 ◽

2006 ◽

Vol 530-531 ◽

pp. 117-125 ◽

Cited By ~ 1

Author(s):

Clarice Terui Kunioshi ◽

Olandir Vercino Correa ◽

Lalgudi Venkataraman Ramanathan

Keyword(s):

Electron Microscope ◽

High Temperature ◽

Scanning Electron Microscope ◽

Fluidized Bed ◽

Oxidation Behavior ◽

Steel Substrate ◽

Alumina Powder ◽

High Temperature Erosion ◽

Thermally Sprayed ◽

Scanning Electron

The erosion-oxidation (E-O) behavior of high velocity oxy fuel (HVOF) sprayed Ni20Cr alloy as well as WC and Cr3C2 cermet coatings on a steel substrate were studied. The E-O tests were carried out in a rig with specimen assemblies that were rotated through a fluidized bed of erodent particles in the temperature range 500-850°C and with erodent impact velocities of 2.5-19.5 ms-1. Alumina powder (~200Am) was used as the erodent. The E-O resistance of the coatings was determined as wastage, as a function of temperature. The three coatings did not exhibit any significant change in E-O at temperatures up to 500-600°C. At higher temperatures, wastage increased with temperature, reached a maximum at 700°C and then decreased with further increase in temperature. Different E-O regimes were identified. The specimen surfaces were examined in a scanning electron microscope and their roughness determined. E-O maps have been drawn that define conditions under which the coatings undergo low, moderate and severe wastage.

Download Full-text