Turbine clearance control coatings and method

A turbine engine with a high-pressure and a low-pressure turbine section comprising:

• a casing and at least one turbine blade rotatably mounted within the casing, wherein at least part of an inner surface of the casing is covered with an abradable shroud material to provide clearance control between the inner surface and a tip of the at least one turbine blade,
• wherein the tip of the at least one turbine blade is coated with a hard PVD coating,
• wherein the abradable shroud material of the high-pressure and/or the low-pressure turbine section comprises a porous material made of CoNiCrAlY-hBN, NiCrAl-bentonite, NiCrAl-hBN or NiCrFeAl-hBN, and
• wherein the hard PVD coating on the tip of the at least one turbine blade consists of a droplet-free nitride PVD coating, the nitride PVD coating comprising Me1Me2X, where:
• Me1 is an element of the group formed by Ti, Cr or Zr, or a combination thereof,
• Me2 is Al and/or Si, and
• X is an element of the group formed by N, or N and O, or N and B, or N and O and B.