Abstract: An apparatus and method for evaluating thermal barrier coating material on a surface of a part or component that is subjected to transient heat/thermal cycles. A pulsed laser heating apparatus that preferably uses lenses and optical fiber focusing components simulates conditions of brief heating on the test specimen. In the method of the invention, the temporal shape, spatial distribution, and total energy of the laser pulse are designed to produce a spot of uniform illumination and heat absorption on the test specimen that closely approximates the thermal loading that the specimen is expected to receive during use. The test specimen is then examined for thermally induced changes.

Abstract: A window assembly for transmitting light into and from a vessel containing a high pressure, high temperature, highly reactive environment includes a truncated conical window which is substantially transparent to radiation, a truncated conical metal seal which circumferentially engages the window, and a case to which the window and the seal are secured. To facilitate automatic cleaning of the window, the surface of the window which is exposed to the high-pressure environment is seated substantially flush with the high-pressure surface of the case. By initially seating the window assembly by means of mechanical pressing, then subjecting the window assembly to a series of successively higher transient combustion pressures, a window assembly can be fabricated which can withstand prolonged service in a harsh environment such as that encountered in a large caliber artillery cannon or equivalent scientific and industrial applications.