Turbine abradable layer with progressive wear zone multi depth grooves

A method for reducing turbine engine blade tip wear, comprising:

• providing a turbine having a turbine housing, a rotor having blades rotatively mounted in the turbine housing, distal tips of which forming a blade tip circumferential swept path in the blade rotation direction and axially with respect to the turbine housing;
• inserting a generally arcuate shaped abradable component in the housing in opposed, spaced relationship with the blade tips, defining a blade gap there between, and the abradable component having:
• a support surface for coupling to the turbine casing;
• a thermally sprayed ceramic/metallic abradable substrate coupled to the support surface, having a substrate surface adapted for orientation proximal a rotating turbine blade tip circumferential swept path;
• a plurality of elongated continuous tip surface first ridges projecting from the substrate surface;
• a first groove formed in the abradable substrate surface between a pair of first ridges, having a first groove depth;
• and
• a second groove formed in the abradable surface between a pair of first ridges, having a second groove depth that is deeper than the first groove depth;
• and
• operating the turbine engine, so that any contact between the blade tips and the abradable surface initially abrades the first ridges bounding the first groove, so that the first ridges bounding the second groove inhibit turbine gas flow between the blade tips and substrate surface without rubbing the blade tips.

A turbine engine, comprising:

• a turbine housing;
• a rotor having blades rotatively mounted in the turbine housing, distal tips of which forming a blade tip circumferential swept path in the blade rotation direction and axially with respect to the turbine housing;
• wherein the engine is capable of starting in both standard mode, less than 40-50 Mw/minute power output ramp up rate, and fast mode, equal to or greater than 40-50 Mw/minute power output ramp up rate, without modifying turbine blade tip gap;
• and
• a thermally sprayed ceramic/metallic abradable component having:
• a support surface for coupling to a turbine casing;
• an abradable substrate coupled to the support surface, having a substrate surface adapted for orientation proximal a rotating turbine blade tip circumferential swept path;
• a plurality of first ridges projecting from the substrate surface defining a blade tip gap between the ridges and the blade tips;
• a first groove formed in the abradable substrate surface between a pair of first ridges, having a first groove depth;
• and
• a second groove formed in the abradable surface between a pair of first ridges, having a second groove depth that is deeper than the first groove depth.