Laser powder bed fusion (L-PBF) technology has been widely used in the integration forming of complex parts. However

the thermal stress generated by the rapid heating and cooling during the printing process affects the forming quality of parts. In this study

a two-scale model of TC4 alloy L-PBF forming process was established based on finite element method (FEM) at micro and macro-scale. At the micro level

the real-time temperature fields and stress distribution during three-layer scan process were evaluated

and the effects of process parameters and printing layers on the microscale such as melt pool size were explored. It was found that the growth of the melt pool size was more sensitive to power

and high power could release the accumulated thermal stress in the lower layers

but it also had a higher cooling rate which would increase the maximum thermal stress. At the macro level

the overall printing model of the part was constructed

  and the forming parameters were adjusted based on the microscopic scale results. The residual stress distribution and deformation results were predicted

and good agreement was found between the two. Based on the actual printing results of the component

by constructing a compensation model

the maximum displacement was reduced from 0.626 mm to 0.027 mm

a decrease of approximately 95.7%; The average displacement was reduced from 0.595 mm to 0.024 mm

a decrease of approximately 95.97%

and the calculation time was controlled within a reasonable range.