Micro-Scale Deformation Aspects of Additively Fabricated Stainless Steel 316L under Compression.

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Investigating micro-mechanical properties of additively manufactured materials is crucial for understanding their performance.
• Stainless steel 316L is a widely used alloy in various industrial applications.
• Comparing additive manufacturing (AM) with conventional methods highlights advancements in material processing.

Purpose of the Study:

• To investigate the deformation aspects and micro-mechanical properties of powder laser bed fusion (P-LBF) processed stainless steel 316L.
• To compare these properties against conventionally cast stainless steel 316L.
• To analyze the microstructural differences influencing mechanical behavior.

Main Methods:

• Fabrication of micro-pillars from P-LBF and cast stainless steel 316L specimens.
• In situ compression testing of micro-pillars within a scanning electron microscope (SEM).
• Post-deformation microstructural examination using electron microscopy.

Main Results:

• P-LBF processed steel exhibited equiaxed and elongated grains with melt-pool characteristics, while cast alloy showed circular grains with micro-twins.
• P-LBF stainless steel 316L demonstrated significantly higher yield stress (431-474 MPa) and ultimate compressive stress (548-683 MPa) compared to cast alloy (322 MPa and 477 MPa, respectively).
• Both P-LBF and cast specimens displayed ductile-type deformation.

Conclusions:

• Additive manufactured stainless steel 316L via P-LBF possesses superior micro-mechanical properties over conventionally cast counterparts.
• Microstructural differences, including grain morphology and arrangement, are key factors in the enhanced mechanical performance of P-LBF steel.
• The study confirms the viability of P-LBF for producing high-performance stainless steel components.