The use of laser surface melting to homogenize Fe-Al bronzes

Abstract

Laser surface melting has been used to homogenize the near-surface region of several Fe-Al bronzes. A continuous CO2 laser beam was focussed onto the sample surface while the samples moved at high velocities in order to produce melt stripes. The quenched regions were approximately 10μm deep. In the case of the aluminium bronzes C-61 400 and C-62 400 iron-rich precipitates have been eliminated from the surface region. For C62 400 the pre-irradiation matrix isα +γ 2, following laser processing, a single phase, presumably metastableβ, is formed in the quenched region. The aluminium bronze C-62 500 is not homogenized to the same degree as the C-61 400 or C-62 400. Sample analysis was carried out utilizing optical microscopy, scanning electron microscopy, energy dispersive X-ray analysis and scanning Auger microscopy.