Strength Properties of 316L and 17-4 PH Stainless Steel Produced with Additive Manufacturing

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Additive manufacturing (AM) offers new material possibilities, including metal-filled filaments for fused filament fabrication (FFF).
• While tensile properties are known, the fatigue performance of metal FFF parts is largely uninvestigated.
• Existing research gaps hinder the assessment of metal FFF for structural applications.

Purpose of the Study:

• To evaluate the tensile, fatigue, and impact strengths of metal FFF 17-4 PH and 316L stainless steel.
• To compare metal FFF properties against selective laser melting (SLM) manufactured 316L variants and literature data.
• To determine the suitability of current metal FFF technology for safe structural component manufacturing.

Main Methods:

• Tensile, fatigue, and impact testing of Markforged 17-4 PH and BASF Ultrafuse 316L stainless steel produced via FFF.
• Comparison with 316L stainless steel samples fabricated using selective laser melting (SLM).
• Analysis of material defects, surface roughness, and internal voids impacting mechanical properties.

Main Results:

• Metal FFF specimens exhibited significantly reduced tensile and fatigue strength compared to SLM-produced counterparts.
• Surface roughness and internal voids in FFF parts act as stress concentrators, diminishing strength.
• Impact strength data was also analyzed in comparison to SLM and literature values.

Conclusions:

• Current metal FFF technology demonstrates inferior tensile and fatigue performance compared to SLM.
• Internal material defects inherent in the FFF process limit its application for structural components.
• Further advancements in metal FFF are required to mitigate defects and ensure safe use in structural applications.