nir-vana innovation network

During the machining process to manufacture parts with different materials, the temperature increases as the tools rubs against the part and removes the material. The measurement thereof helps to determine the degree of wear of the tool, and therefore helps to prevent its deterioration and plan its replacement. This factor is an important element to take into consideration, since it reduces the productivity in machining processes.
Likewise, it is important to know the surface integrity that the material retains after machining. The temperature measurement is a parameter that helps to know and improve the quality of the cut part, which is of vital importance when it is part of critical machines, such as for example, in aircraft engines.
A research group from a Spanish public university has developed a pyrometer for measuring high temperatures greater than 270°C in hostile and hard-to-access environments, such as next to rotating components in machining processes with machine tools.
The device is based on measuring, through an optical fibre, the radiation emitted by the analysed body. In order to prevent errors associated with possible lack of information about the emissivity of the material, or a possible change over time of the surface conditions, the measurement is performed in two different spectral bands. This technique is the so-called bi-colour optical fibre pyrometry.
One of it main improvements is the use of an optical fibre compatible with systems and components integrated on the optical communications Systems. Moreover this technology presents significant enhancement in measurement sensitivity and high acurancy (less than 1% of error).
The use of two very close spectral bands also has the advacement of using only one type of photodiode and the bands being distinguished with a conventional optical demultiplexer, minimizaing potential errors in view of emissivity variation.
Other techniques are based on sensors with thermistors and thermocouples that must be in direct contact with the surfaces to achieve thermal equilibrium, which can be difficult and complex whith a lack of space o on moving surfaces.
Currently infrared thermography techniques are not applicable, since there is not direct line of view from the camera to the cutting point , due to the fact that the cut must be made with the machine closed for safety reasons.
Nowadays optical fibre pyrometers Systems are used in part drilling processes, not in machining. They have two photodetectors with measurement bands far from each other, sensitive to different spectral ranges, which increases errors in view of emissivity variation and makes them less efficient.
The developed pyrometer resolves problems inherent to other techniques, so it is of interest for companies that manufacture machine tools and want to integrate this additional functionality for interested users. Also can be interesting for companies that manufacture high precision parts for sectors with very strict quality controls, such as the case of aeronautical industries.
The researchers are looking for manufacturing companies for license and/or technical cooperation agreements for developments oriented to specific applications to integrate the technology in manufacturing processes of interested companies

Advantages & innovations

Innovative aspects: - Bi-colour optical fibre pyrometer - Temperature measurement in hostile and hard-to-access environments - Use in machining processes with machine tools - Uses two very close spectral bands in the measuring process - Uses opto-electronic components and conventional optical fibre for optical comunications - Integrates the optical fibre in the cutting tool even in small spaces Advantages: - Prevents measurement errors associated with change in the emissivity of the material - Uses opto-electronic components and conventional optical fibre for optical communications - Uses only one type of photodiodes - Does not need collimating lenses - Significantly improves measurement sensitivity and precision with respect to other techniques - Reduces by more than half the costs of the system - Integrates the optical fibre in the cutting tool even in small spaces - Allows access to the measurement area, without having to access the lathe or other fixed parts - Helps to prevent cutting tool deterioration and plan its replacement, improving total productivity - Helps to know and improve the quality of the cut part

Stage of development

Available for demonstration

Partner sought

Technical cooperation agreement: Partners from manufacturing branches (especially metal parts producing and processing companies) are sought who want to improve their production processes, i.e. less wear of machinery and production equipment, reduced production downtime and improved productivity. Together with the partner the research team would like to assist in implementing the temperature measurement technology in the partner’s production cycles to run field trials. License agreement: The company offers licenses of their technology which can be purchased by interested companies. The research team is open to discussions to evaluate if the technology can be applied in the potential partners’ processes