Effects of micro laser sintering process parameters on quality of nickel-titanium single tracks and thin walls

Micro laser sintering is a promising additive manufacturing process for production of parts with micro features and complicated geometries. Micro laser sintering of mechanically alloyed NiTi was performed in the present work. The effects of powder and laser defocusing distances and also process parameters on the surface quality of single tracks and thin walls were investigated by scanning electron microscopy and optical profilometry. A modified model was described in this research to calculate the height of thin walls produced by micro laser sintering. The experimental results showed that a high melting efficiency can be obtained when the focal point of the laser is situated 200 µm above the working plane of the specimen. Optical profilometry revealed a good agreement between the proposed model for thin wall’s height estimation and experimental results.