• Aleem, B. J. Abdul
• Yilbas, B. S.
• Leyland, A.
• Akhtar, S. S.
• Matthews, Allan
• Karatas, C.

Abstract

<p>One technique to improve tribological properties of aluminum bronze surfaces is to introduce laser controlled melting at the surface in the presence of a composition-modifying film. In this work, a 40 μm thick organic film, containing B₄C particles, was formed at the workpiece surface prior to laser treatment. The organic coating provides enhanced absorption of the incident laser radiation and distributes the B₄C particles uniformly across the surface. Morphological and microstructural changes in the laser treated layer were examined using scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The microhardness of the laser treated layer was measured and the residual stress formed at the treated surface was evaluated by X-ray diffraction using the sin²ψ technique. It was found that the laser treated surface produced is relatively free from defects and asperities with a microhardness that is notably higher than that of the as-received bronze substrate. This hardening effect can be attributed to the development of a dense layer consisting of fine grains, partially dissolved B₄C particles, and formation of Cu₃N compounds. The residual compressive stress obtained from X-ray diffraction peak evaluation is of the order of -400 MPa.</p>

Topics

• impedance spectroscopy
• surface
• compound
• grain
• scanning electron microscopy
• x-ray diffraction
• aluminium
• defect
• X-ray spectroscopy
• aluminum bronze