Laser-DED Process of Inconel 718 Alloy Powder

Compared with wire feed materials, Inconel 718 alloy powder provides superior material utilization and cost-effectiveness. Its feeding rate is faster, and when paired with the laser’s high energy density, it greatly improves deposition efficiency. Through layer-by-layer buildup, this approach allows flexible manufacturing of complex metal parts, breaking through the geometric constraints of traditional subtractive methods.

By dynamically adjusting the laser power and incorporating a coaxial infrared pyrometer, it becomes possible to realize closed-loop monitoring of the melt pool temperature, providing excellent potential for precise and adaptive thermal control.

Experimental Setup:

However, this technology also faces notable challenges in practice. Multi-layer deposition tends to cause heat accumulation, which can enlarge the melt pool, increase vertical dimensional deviation, porosity, and grain coarsening.

The repetitive scanning paths further amplify thermal gradient fluctuations, resulting in spattering and balling, thus reducing structural uniformity.

Morphology of gas atomized Inconel 718 powder:

It can be observed that there are some Satellite and agglomerated particles from gas atomized Inconel 718 powder.

Irregular melt paths and rough surface morphology deposited by gas atomized Inconel 718 powder:

Morphology of PREP Inconel 718 powder:

It can be observed that there are not any Satellite and agglomerated particles from PREP Inconel 718 powder.

By changing the Inconel 718 powder from gas atomized type to PREP type, the vertical dimensional deviation was reduced greatly by 85% and improved structural uniformity by 98% due to more uniform particle size and more sphericity of PREP powder to stabilize the melt pool dynamics.

And the DED parts by PREP Inconel 718 powders have least defects and discontinuities due to almost zero hollow and satellite powders of PREP powder.

Surface morphology deposited by PREP Inconel 718 powder: