Composite CFRP Drilling Enviromentally Friendly Coolant System

This Small Business Innovation Research (SBIR) Phase I project aims to develop a novel environmentally-friendly CO2 coolant system to drill CFRP-Ti (Carbon Fiber Reinforced Plastic with layers of Titanium) used in the aerospace industry. Carbon dioxide will be applied as frozen dry-ice (CO2) particles through the drill stem directly into the drill cut zone, providing significant controllable cooling and lubrication to the drill and the surrounding CFRP-Ti material. A bio-based lubricant may be added to provide additional lubrication if necessary. The broader/commercial impact of this project will be the potential to provide an environmentally-benign coolant system for CFRP-Ti drilling applications. The aerospace industry is using more CFRP-Ti in aircraft components as it is more durable and lighter than aluminum or similar metals. However, CFRP-Ti is abrasive and difficult to drill, resulting in significant heat being generated from the force and the friction of drilling, which is detrimental to the CFRP base materials. The industry currently uses petroleum oil and water for cooling, which has following problems, (1) it does not provide adequate cooling; (2) it is not environmentally friendly and must be treated as hazardous waste; (3) it requires biocides to reduce bacteria; and (4) it is not conducive to a healthy and safe worker environment. This project may provide a novel coolant system with environmental benefits, improved quality, and reduced cost structure. Furthermore, the CO2 used in this process will be recycled from other industrial sources, thereby not a CO2 generator.