TURBINE BLADE TIP HAVING THERMAL BARRIER COATING-FORMED MICRO COOLING CHANNELS

摘要

The present invention provides for cooling the squealer tip region of a high pressure turbine blade used in a gas turbine engine comprising coating the squealer tip with a metallic bond coat. Micro grooves oriented in the radial direction are fabricated into the airfoil on the interior surface of the squealer tip above and substantially perpendicular to the tip cap. A micro groove oriented in the axial direction is fabricated along the joint corner between the squealer tip side wall and the tip cap to connect and act as a plenum with all of the micro grooves oriented in the radial direction. Tip cap cooling holes are drilled through the tip cap and connected to the micro groove that ultimately forms a plenum. TBC ceramic is then deposited on both blade external surfaces and the tip cavity, forming micro channels from micro grooves as a result of self shadowing. In this manner, cooling fluid passes from a cooling fluid source through the tip cap holes and into the plenum created by the micro channel, subsequently passing into the micro channels that are oriented in the radial direction. Cooling fluid is thereby directed through the micro channels to cool the squealer, exiting in the vicinity of the tip. Since the TBC is porous, some of the cooling fluid will also flow through the TBC to provide transpiration cooling. The present invention further comprises both the cooled blade and squealer tip region formed by the foregoing methods and the blade and squealer tip with the micro channels for cooling the squealer tip.