Fiber Sensors Go Inside Hot Machining Processes

Fiber optic pyrometers that can get into places that other heat sensors cannot could help metal parts manufacturers cut down defects and breakdowns.

Researchers at Carlos III University of Madrid have developed 62.5-µm silica fiber sensors that measure heat radiated by mechanical or cutting processes. The system measures radiation in two colors and calculates temperature based on the quotient of the two signals. The fibers can operate at temperatures from 300 to 1000 °C.

In these environments, thermographic IR cameras cannot be used because there is not a clear line of sight to the tool’s cutting point. Thermocouples or other sensors can’t be used either because of the deterioration they will suffer and the difficulty of establishing a good location for them due to inaccessibility.

Obtaining temperature-change data during cutting helps in the analysis of the evolution of wear on a tool, making it possible “to optimize the life of the tool, thereby improving productivity,” said professor Dr. Carmen Vazquez.

Temperature data can also indicate if the workpiece has taken heat damage during the machining process. This could be crucial in the aerospace industry, Vazquez said.

The sensors could also be used in biomedical applications where patient temperature must be monitored closely, as the researchers discuss in a recent Sensors paper (doi: 10.3390/s141224029 [open access]).

Funding for the work came from the Spanish Ministry of Economics and Competitiveness and the Autonomous Community of Madrid

For more information, visit www.uc3m.com.