Research on the forming process of three-dimensional metal parts fabricated by laser direct metal forming

Abstract

To improve the forming quality of parts fabricated by laser direct metal forming (LDMF), the forming process of three-dimensional parts under open-loop LDMF system was studied in this paper. The influencing rule of scanning space on the forming quality was studied, and the optimal scanning space was derived. The software of control system about scanning style is also optimized, and thus, the forming quality of parts is improved. During fabricating three-dimensional parts, uneven heat distribution caused by multi-overlapping is one of the main factors affecting the sidewall forming quality. To solve the uneven heat distribution, the strategy of changing scanning speed was put forward. The influence of the standoff distance on the height of single-trace cladding layer was studied, and it was suggested that uneven surface of parts was caused by instability of process parameters, which could be compensated automatically in the condition of suitable standoff distance in the process of LDMF. Thus a so-called self-regulation effect is reached. Typical multi-overlapped parts with good forming quality are fabricated using the above-mentioned methods.