Study on Microstructure Unevenness of Production by Laser Rapid Manufacturing

According to the development of rapid prototyping, fundamental experiments on rapid manufacturing of metallic parts by high power CO2 laser were carried out and the microstructure unevenness of the production was discussed systemically. It is indicated that with the increasing of scanning times by laser, the layer microstructure of the production are coarsened. At the same time, the internal microstructure of the production layer change from micron equiaxed crystal to dendrite crystal, the microstructure of the interface of two neighboring layers is consisted of ultra fine equiaxed crystals, coarser lathing structures and dendrite crystals.