Laser Welding of Lotus-type Porous Iron

摘要

Lotus-type porous metals, whose pores are formed by supersaturated gas utilizing the difference of gas solubility between liquid and solid and are aligned in one direction by unidirectional solidification, have higher strength than the conventional foamed porous metals. Thus, lotus-type porous metals have a high potential as structural materials with functional properties by porosity. There are expected industrial applications such as car materials which need the strength, lightweight and functional properties of the high impact energy absorption as well as the insulation for sound and vibration. Therefore, a reliable joining technology such as welding is required to make the joint components between the porous materials or with non-porous materials. In this study, the lotus-type porous iron fabricated by unidirectional solidification of continuous zone melting technique in a pressurized nitrogen atmosphere at 2.5 MPa, was chosen as the work piece. A Nd:YAG laser welding with a narrow weld bead width and heat affected zone was applied to evaluate the melting characteristics of lotus-type porous iron.