Determination of process parameters for additive manufacturing with Inconel 718 powder

Abstract In this study, the additive manufacturing (AM) of Inconel 718 was investigated, and the processing parameters can affect the mechanical properties of the product. The five-axis laser cladding composite processing machine Tongtai AMH-630 is used, and the laser power is set to 800W based on the thermal impact of the laser on the base plate. However, the laser scanning speed (600-1200mm/min) and powder feed rate (3~15g/min) are not arbitrary combinations. It is recommended to present the feed per unit length in g/mm, which seems to be more clearly expressed. Regardless of changes in laser scanning speed and wheel speed, it is a reasonable decision to control the combination of the two at about 0.01-0.013g/mm. Through single-pass cladding experiments, we select different combinations of laser scanning speed and powder feed rate with a cladding aspect ratio in the range of 3:1 to 4:1. In the multi-pass cladding experiment, an overlap rate of 30% was used as the plane cladding spacing; a spacing of 80% of the cladding height was used as the stacking height. This study uses scanning speeds of 600, 700, 800, 1000 and 1200mm/min to clad a rectangular body. Tensile test specimens were processed using a CNC lathe, and tensile tests were conducted to obtain variations in tensile strength and elongation at different scanning speeds. The mechanical properties of both will decrease as the scanning speed increases. At a scanning speed of 600mm/min, its tensile strength is comparable to that of Inconel 718 standard materials; but its elongation is 61% of that of standard materials. If Hot Isostatic Pressing (HIP) is applied after cladding, it seems that a higher scanning speed can achieve a performance closer to that of standard materials.