Effects of blade surface treatments in tip-shroud abradable contacts

Grit (cBN) tipped blades load with abradable material after a period of efficient cutting causing grit pull out and fracture. Flat Cr(Al)N coated blades failed due to thermal damage to the coating caused by adhesion of abradable material onto the Cr(Al)N coating, while chamfered blades cut efficiently at low incursion rates.