Cryogenic machining 'guarantees safety' of aerospace sector parts
25 April 2013
Researchers in Spain are investigating the benefits of cryogenic machining - in particular, for ensuring the safety of parts manufactured for the aerospace sector.
Cryogenic machining has less impact on the environment than conventional methods; moreover, it considerably enhances the useful life of machined parts and reduces costs.
CIC marGUNE, the Cooperative Research Centre for High-Performance Manufacture, is working on this project in collaboration with the High-Performance Manufacturing Group at the Higher Engineering School in Bilbao (UPV/EHU), Tecnalia and the University of Mondragon.
The method involves employing refrigerant gas in the process of machining. The aim of this research project is to guarantee a clean manufacturing process and, moreover, to contribute to the safety integrity of parts manufactured for the aerospace sector.
Conventional machining involves the use of cutting fluids which lubricate and cool the cutting zone. However, these fluids are harmful to the environment and pose health risks for machine operators. Cryogenic machining - a method of refrigerating the cutting tool and the critical points of the part during machining - solves these problems, thanks to the use of a cold refrigerant gas, such as liquid nitrogen or CO2.
Both liquid nitrogen and CO2 are basic and cheap, and CO2 can be applied with minimal modifications.
According to the researchers, the process also eliminates machining defects, as it avoids changes in the microstructure of the tool due to the high temperatures that can be reached at the cutting zone. The researchers actually put a figure on the improvements - an increase in the life of machined parts of between 50 and 100 percent, and improvements in their resistance to wear and tear, longer fatigue life, and so on.
The system can work at higher speeds than those of conventional machining machines. Thus, productivity is increased and work of a higher quality is obtained, resulting in a reduction in the costs of producing the parts.