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- Meijer, J., et al.
(author)
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Phase transformations by high-intensity sub-microsecond laser pulses.
- 1992
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In: Proceedings of the laser materials processing symposium, ICALEO '92. - Orlando, Fla : Laser institute of America. - 0912035498 ; , s. 228-236
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Conference paper (peer-reviewed)abstract
- In certain alloys, the 'laser shocking' causes work hardening, an increase in dislocation density and phase transformations. Of the materials tested, and austenitic Hadfield manganese-alloyed steel target was found to have the strongest tendency for a martensitic phase transformation. In contrast with conventional transformation hardening, there is no tempering in the case of repeated application. Whilst most material is vaporized, some surface melting will occur. The rate of re-solidification of the molten material is such that an almost completely amorphous structure results. The martensitic transformation has been confirmed by using optical, scanning and transmission electron microscopy, OM, SEM and TEM/STEM. Two different lasers, a Q-switched Ruby and a Q-switched Nd:YAG were used for the experiments. Calculations of impact/momentum, peak pressure and peak temperature were performed using the finite difference method. The model used for simulating the process has been proved to be useful in understanding the transformation mechanism.
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