Abstract
In this paper, the three dimensional laser fabrication of aluminum alloy is investigated. While the processed bead of pure aluminum powders by laser irradiation is ordinarily discontinuous in the shape of balls and is not welded to the base plate, the continuous bead suitable for a fabrication unit can be processed using aluminum powders compounded with alloy elements. A smooth bead with deviation of the maximum height of less than 0.1mm is obtained on the titanium base plate under the optimum processing conditions. The bead of the aluminum powders compounded with 5-7.5wt% the silicon and 5wt% the titanium can be laminated to the plate of smooth top without cracks or detachment from the base plate by the change of melting and solidifying process. In this processed bead the eutectic microstructures are observed containing aluminum-silicon alloy and Al3Ti distributed minutely with the grain size under 20 micrometer. The average tensile strength of this processed plate is equivalent to pure aluminum at 82 MPa. Three dimensional shapes of aluminum alloy, for example quadrangular pyramids, are fabricated easily with smooth appearance of the surface.
