Product Code: ICAL08_N204

Scale-up of Nanoparticle Production during Laser Ablation of Ceramics in Liquid Media
Authors:
R. Sattari, Laser Zentrum Hannover e. V.; Hannover Germany
C.L. Sajti, Laser Zentrum Hannover e.V.; Hannover Germany
S. Khan, Laser Zentrum Hannover e.V.; Hannover Germany
S. Barcikowski, Laser Zentrum Hannover e.V.; Hannover Germany
Presented at ICALEO 2008

Press-cylinders and stamping tools are widely-used by the paper industry. Their surfaces require high abrasive resistance, which can be achieved by including ceramic nanoparticles into plasma coating and laser sintering. An admixture of nearly 10% of ceramic nanoparticles into a hard metal microparticle powder stream can have a promising impact on the increase of the abrasive resistance surface properties. Based on this motivation a laser-based process shall be used for continuous generation of ceramic nanoparticles in a flow of liquid aiming at a high productivity of ablated material mass per hour. The laser-assisted ablation technology in liquid phase has advantages like the generation of dispersed and size-controlled nanoparticles in liquid media. The investigations show a significant increase of productivity when reducing the liquid layer height above the target using a pulsed laser (λ = 1047 nm, pulse energy = 4 mJ, pulse duration = 60 ns, rep. rate = 5 kHz). Furthermore, positioning of the focussed laser beam shows an increase of the nanoparticle productivity reaching values up to 450 mg/h using a defined liquid layer. The results of the investigations lead to a method with adequate productivity for a promising impact on abrasive resistance surface properties of machining tools.