The laser-assisted interference technique involves two or more beams to create power variation on a surface. Those beams are guided to the sample surface by overlapping each other with defined angles to one another. Instead of simply adding intensity, the coherent beams create an interference pattern. This allows a microscopic modulation and creates a light pattern without any loss of energy during the interference process. Patterns can be dot, line, and ring shaped.
ORNL's advanced laser structuring facility includes a Q-switched Nd:YAG (neodymium-doped yttrium aluminium garnet) laser system with a harmonic generator that allows for the selection of one of four very sharp wavelengths: 1064, 532, 355, or 266 nm. The trigger system's frequency 10Hz, and the pulse duration is 10 ns, which accommodates heating and cooling rates above 1012K/s.
Laser-assisted surface structuring has been proven for lubrication, adhesive bonding of dissimilar materials (Al, carbon fiber polymer composites, Mg, steel), and wear resistance applications. The following structure capabilities are possible (surface morphology is shown in Figure 1):
- Ondulation spacing : 0.5-50 _m
- Density: 200-20,000/cm
- Feature size: 1-500 nm
- Structured area: 0.27 cm2/shot
- Velocity: 10,000 lines at a time and 79 million dots at a time, up to 162 cm2/min.
In addition, several high-power and long-pulse systems are available.
These facilities are available for various partnership arrangements with industry.
Dr. Adrian Sabau, Senior Staff Scientist, email@example.com, 865-241-5144
- A.S. Sabau, J. Chen, J. F. Jones, A. Hackett, G. D. Jellison, C. Daniel, D. Warren, J. D. Rehkopf, Surface Modification of Carbon Fiber Polymer Composites after Laser Structuring, 2015 TMS Annual Meeting & Exhibition, Proceedings: Adv. Composites for Aerospace, Marine, and Land Applications II, Orlando, Florida.
- J. Chen, A.S. Sabau, J. F. Jones, A. Hackett, G. D. Jellison, C. Daniel, and D. Warren, "Aluminum Surface Texturing by Means of Laser Interference Metallurgy," 2015 TMS Annual Meeting & Exhibition, Proceedings: Light Metals 2015: Aluminum Processing, pp. 427-429, Orlando, Florida.