Optimizing Laser Powder Bed Fusion Parameters for IN-738LC by Response Surface Method.

Area of Science:

• Materials Science
• Additive Manufacturing
• Metallurgy

Background:

• Nickel-based superalloys like Inconel 738LC are prone to cracking during Laser Powder Bed Fusion (LPBF).
• Optimizing process parameters is crucial for producing high-quality Inconel 738LC components via LPBF.
• Minimizing defects such as pores and cracks is essential for the integrity of LPBF-processed superalloys.

Purpose of the Study:

• To develop a method for optimizing process parameters for Inconel 738LC (IN738LC) manufactured by LPBF.
• To identify process parameters that minimize porosity and crack density in LPBF-processed IN738LC.
• To validate the effectiveness of the Response Surface Method (RSM) in achieving optimal LPBF parameters for IN738LC.

Main Methods:

• A Design of Experiments (DoE) approach was used to systematically vary LPBF parameters (laser power, scan speed, hatch distance, scan strategy).
• Quadratic models were fitted to porosity and crack density data obtained from DoE samples.
• The Response Surface Method (RSM) was applied to identify the optimal processing window.

Main Results:

• The study successfully identified optimal LPBF parameters for IN738LC.
• Manufactured samples using predicted optimal parameters exhibited no cracks.
• Porosity levels in the optimized samples were consistently below 0.1%.

Conclusions:

• The Response Surface Method (RSM) is a suitable and effective tool for optimizing LPBF process parameters for Inconel 738LC.
• Achieving crack-free and low-porosity IN738LC components is feasible with optimized LPBF parameters.
• This work demonstrates a pathway to high-quality additive manufacturing of nickel-based superalloys.