National Center for Hydrogen Research

Laser Laboratory

TBC Blade coupon under laser irradiation to test high temperature coating performance.

The High Heat Flux Test Laboratory “Laser Lab” at the Florida Institute of Technology (FIT) is a state-of-the-art purpose built facility for testing ceramic thermal barrier coatings used in the turbine engine industry. Utilizing a 2.2 kW CO2 laser, pyrometer thermal sensors, various camera systems, a high pressure, high flow compressor, all controlled and monitored via a custom software application written in LabVIEW, we are able to test ceramic thermal barrier coatings across a variety of temperatures up to 1700° C, continuously monitoring and recording all data at the rate of 1 data sample per second (1 Hz).

Important features: Noncontact with specimen, instantaneous heat flux or computer control of heat flux, computer controlled cooling, no contamination by container, and gaseous environments acceptable.

The test rig is composed of the following components:

  • Frame mounted CO2 laser (PRC Laser Model STS3300 configured to operate in the TEM00 mode at
    up to 2.2 kW) and associated delivery optics.
  • Steel test frame and aluminum test stand.
  • Button work station with colling mount.
  • Component work station with blade cooling fixture.
  • Ircon Modline 3 pyrometer, operating at 7.92µ from 200 to 1800° C.
  • Mikron Infrared Model MI-SQ5-TV pyrometer, operating at 10.6µ from 700 to 1800° C.
  • Atlas-Copco Compressor (Model GA 18+).
  • Brooks Mass Flow precision, computer controlled air valve operating at 225 PSI up to 2500 liters per
    minute flow rate.
  • PC Computer running the Laser Rig 2.0 custom LabVIEW application.
    • This software controls all functional elements of the test rig, collects and records the data from the pyrometers, laser, and cooling air (Brooks MF device), and provides safety protocols to prevent catastrophic failure of the test rig.
  • High resolution Ethernet camera to monitor the test sample.
  • Several HD webcams to monitor other areas of the test rig.

The collimated/expanded laser beam is emitted from the laser aperture and travels to the 45° turning mirror, where it is directed down through the final focusing lens and onto the test sample mounted on the test stand.

45 degree mirror

The sample is illuminated from above by the laser, and cooled from below by the Brooks valve controlled cooling air. The sample is attached to the test rig (not shown) by a motorized shaft, rotating at 60 rpm. This distributes the laser energy radially and homogenizes the heating.

The upper and lower sides of the test sample are monitored by off optical axis pyrometers. The hot side pyrometer is centered at 7.92µ to discriminate from the 10.6µ laser wavelength, while the bottom side is centered at 10.6µ.

Hot and Cold side Pryometer

The LabVIEW application software controls and monitors all aspects of the laser test rig, including the laser, Brooks Mass Floow valve, and pryometers. The data from the pryometers, the laser, and the Brooks valve is recorded into comma-seprated-values files through the application for later analysis.