Polymer-coated blade with abrasive tip

Abstract

A friction interface in a gas turbine engine includes an abradable component, such as a seal, and an abrasive component, such as a blade tip, in rubbing contact with each other. The abradable component is composed of a polymer matrix composite and the abrasive component is composed of a metal matrix with hard particles dispersed through the metal matrix. The metal matrix is an aluminum alloy and the hard particles are selected from oxides, nitrides, carbides, oxycarbides, oxynitrides, diamond and combinations thereof.

What is claimed is: 
     
         1 . A friction interface in a gas turbine engine, comprising:
 an abradable component and an abrasive component in rubbing contact with each other, the abradable component being composed of a polymer matrix composite and the abrasive component being composed of a metal matrix and hard particles dispersed through the metal matrix, and the metal matrix is an aluminum alloy and the hard particles are selected from the group consisting of oxides, nitrides, carbides, oxycarbides, oxynitrides, diamond and combinations thereof.   
     
     
         2 . The friction interface as recited in  claim 1 , wherein the aluminum alloy is a eutectic aluminum-silicon alloy. 
     
     
         3 . The friction interface as recited in  claim 1 , wherein the hard particles have a particle size of 10 micrometers to 200 micrometers. 
     
     
         4 . The friction interface as recited in  claim 1 , wherein the hard particles protrude from the metal matrix. 
     
     
         5 . The friction interface as recited in  claim 1 , wherein the abrasive component has, by volume percent, 0.1% to 50% of the hard particles. 
     
     
         6 . The friction interface as recited in  claim 5 , wherein the abrasive component has 5% to 15% of the hard particles. 
     
     
         7 . The friction interface as recited in  claim 1 , wherein the polymer matrix composite includes a silica-containing filler. 
     
     
         8 . The friction interface as recited in  claim 7 , wherein the silica-containing filler is hollow glass microspheres. 
     
     
         9 . The friction interface as recited in  claim 8 , wherein the hard particles include at least one of alumina or zirconia. 
     
     
         10 . The friction interface as recited in  claim 9 , wherein the abrasive component has, by volume percent, 5% to 15% of the hard particles. 
     
     
         11 . The friction interface as recited in  claim 10 , wherein the aluminum alloy is a eutectic aluminum-silicon alloy. 
     
     
         12 . A friction interface in a gas turbine engine, comprising:
 an abradable seal and an abrasive tip in rubbing contact with each other, the abradable seal being composed of a polymer matrix composite and the abrasive tip being composed of a metal matrix and hard particles dispersed through the metal matrix, and the metal matrix is aluminum alloy and the hard particles are selected from the group consisting of oxides, nitrides, carbides, oxycarbides, oxynitrides, diamond and combinations thereof.   
     
     
         13 . The friction interface as recited in  claim 12 , wherein the polymer matrix composite includes a silica-containing filler. 
     
     
         14 . The friction interface as recited in  claim 13 , wherein the silica-containing filler is hollow glass microspheres. 
     
     
         15 . The friction interface as recited in  claim 14 , wherein the hard particles include at least one of alumina or zirconia. 
     
     
         16 . The friction interface as recited in  claim 15 , wherein the abrasive component has, by volume percent, 5% to 15% of the hard particles. 
     
     
         17 . The friction interface as recited in  claim 16 , wherein the aluminum alloy is a eutectic aluminum-silicon alloy. 
     
     
         18 . A blade comprising:
 an airfoil section extending between leading and trailing edges, first and second opposed sides each joining the leading and trailing edges, and an inner end and a free tip end,
 the airfoil section being formed of a metal-based material with a polymeric overcoat on at least one of the leading edge, trailing edge, first side and second side, 
 the airfoil section including an abrasive tip at the free tip end, 
 the abrasive tip including a metal matrix and hard particles dispersed through the metal matrix, and the metal matrix being composed of an aluminum alloy and the hard particles being selected from the group consisting of oxides, nitrides, carbides, oxycarbides, oxynitrides, diamond and combinations thereof. 
   
     
     
         19 . The blade as recited in  claim 18 , wherein the polymer matrix composite includes hollow glass microspheres. 
     
     
         20 . The blade as recited in  claim 19 , wherein the aluminum alloy is a eutectic aluminum-silicon alloy.