Selective laser melting (SLM) technology is widely used in the manufacture of complex lattice structures

but the thermal-mechanical behavior of lattice structures affects the forming quality of the workpiece during printing. In order to study the effect of pillar size on the temperature changes

residual stress and deformation of titanium alloy lattice thin-walled parts

three groups of Ti6Al4V lattice thin-walled parts models with different pillar sizes were designed. The temperature change distribution during the forming process was observed

and the Von-Mises stress and deformation of the formed parts after cooling to room temperature were analyzed. The results show that for lattice structures with different pillar sizes

with the increase of pillar size

the maximum instantaneous temperature increases from 1271.35 ℃ to 1396.28 ℃

and the maximum residual stress also increases from 1207.8 MPa to 1369.2 MPa. The larger residual stress is mainly distributed in the node area of each structure

and the stress in the Z-direction is the largest

followed by the X-direction and the Y-direction. Due to the increase of the pillar size

the residual stress and the weight of a single pillar increases

and the deformation of the lattice structure also increases from 0.0919 mm to 0.1730 mm

and the deformation of the pillars on both sides is observed to be the largest. Therefore

in the actual printing process

it is necessary to add support at the position with the maximum deformation according to the simulation results to prevent serious deformation of the thin-walled parts during the printing process

so as to control the forming quality.