Laser surface treatment of aluminum based composite mixed with B4C particles

• Dense layer consisting of fine grains and B4C particles is formed at laser treated surface.
• Self-annealing effect eliminates micro-cracks or crack-network formation in treated layer.
• Microhardness increases at laser treated surface because of dense layer and of AlN compounds.
• Fracture toughness reduces slightly because of microhardness enhancement
• Surface texture composes of micro/nano poles enhances hydrophobicity of treated surface.

Laser treatment of hot pressed mixture of aluminum (85 wt%) and B4C (15 wt%) is carried out. Metallurgical and morphological changes at the laser treated surface are examined using the analytical tools. Microhardness and fracture toughness of the workpiece surfaces are determined prior to and after the laser treatment process. Texture and hydrophobicity of the laser treated surface is assessed incorporating the atomic force microscopy and contact angle measurements. It is found that a dense layer consisting of fine grains of sub-micron sizes (0.8–0.4 μm) and B4C particles is formed at the laser treated surface. Microhardness increases at the laser treated surface because of the presence of the dense layer and the formation of AlN compounds at the surface. Fracture toughness of the laser treated surface reduces slightly because of the microhardness enhancement at the surface. The textures of the laser treated surface compose of micro/nano poles, which result in higher contact angles than that of the untreated surface, and formation of AlN compound adds to the surface hydrophobicity enhancements.