The selective laser melting of 6061 aluminum alloy is often plagued by defects such as porosity, cracking, and coarse columnar grains due to thermal accumulation, which severely limits its mechanical performance and application. This study employed an interlayer pause strategy to control defects and microstructural evolution. The results demonstrate that the interlayer pause (IP) strategy effectively reduces the interlayer temperature and increases the temperature gradient at the molten pool bottom, leading to a shallower pool morphology and decreased melt fluidity. Consequently, the average defect area fraction was reduced from 7.13% to 1.28%, with a suppression effect exceeding 90% for highly defective samples. Under optimal processing conditions, the average grain size was refined to 22.7 μm, accompanied by a significant increase in the equiaxed grain fraction and a marked weakening of texture, as evidenced by a decrease in the maximum pole density from 3.54 to 2.46. Residual stress was also reduced by 36.7%. Mechanically, the yield strength and ultimate tensile strength increased by 12.5% and 10.2%, respectively, albeit with a slight decrease in elongation to 5.35%. The interlayer pause strategy exhibits good universality across different processing parameters, providing an effective pathway for high‐performance additive manufacturing of aluminum alloys.
Huang et al. (Wed,) studied this question.