THE SELECTED PROPERTIES OF FUSION OF FE FOAM AND SHEET METAL WITH USE OF THE ND: YAG LASER

摘要

In the paper there were presented possibilities of combining metal sheet with metallic foams using a Nd: YAG laser. The research were carried out over the properties of laser welded joint of micro-welds iron foam with superalloy HYNESH230. The studies mainly focused on the microstructural and some mechanical properties. Example of structural applications for metallic foams, utilizing benefits in weight, stiffness, energy dissipation, mechanical damping, and vibration frequency were summarized already by many authors. The authors chose to study selected properties of fusion of Fe foam and sheet metal with new approach. Fe foam was prepared according to the method described in the Polish patent No. 199720. There was prepared mixture of iron powder ASC 100.29 (source: the Hoganas company) and iron oxide with different composition. The mixture was sintered in a dissociated ammonia atmosphere. To determine pore size and shape from the foam specimens, image analyzer software was used. Laser beam welding is not only a feasible process for joining sheet metals and Fe foams, but it also seems to be promising for the construction structures, considering the energy absorption and the noise level. The joints were investigated with metallographic methods and EDS analyses. The studies used to determine basic quality parameters of the welded joint. Using EDS analysis, there were identified a types of alloying elements and the extent of diffusion from superalloy H 230 in the course of Fe foam. Also, there was investigated shear strength of obtained micro-welds.