ABRADABLE SEAL

摘要

PURPOSE: An abradable seals, more particularly an use of a laser to texture the surface of a seal material is provided to get an improved abradability CONSTITUTION: A surface of a 304 stainless steel plate approximately 1.5 inches wide and 4 inches long and 0.100 thick is mechanically roughened using 60 mesh aluminum oxide in an aspirated grit blast cabinet. The plate is thermal sprayed coated with a bond coat of Ni-5 wt % Al to a thickness of 0.004-0.006 inches thick. The surface of the bondcoat is then thermal sprayed coated with NiCrAl bentonite (an abradable coating) to a thickness of approximately 0.150 inches. The surface of the abradable coating is machined to produce a surface which is essentially flat and uniform in surface roughness. The coated plate is mounted in the jaws on the computer controlled X-Y table of the laser. A computer program is written and loaded in the computer which produce a diagonal traverse pattern at approximately 45 degree and separated by about 0.050 inches. The laser is energized and allows to engrave the surface of the abradable coating to a depth of approximately 0.050 inches.