How generalisable are material extrusion additive manufacturing parameter optimisation studies? A systematic review.

Area of Science:

• Additive Manufacturing
• Materials Science
• Mechanical Engineering

Background:

• Material extrusion additive manufacturing (ME AM) is a cost-effective method for creating complex 3D geometries.
• However, ME AM parts often suffer from poor dimensional and geometrical accuracy.
• Improving quality requires optimizing printing parameters.

Purpose of the Study:

• To conduct a comprehensive analysis of experimental studies on dimensional quality in ME AM.
• To identify trends and inconsistencies in printing parameter optimization over the past 25 years.
• To evaluate the generalizability of findings from existing research.

Main Methods:

• A non-systematic scoping study followed by a systematic literature review protocol.
• Identification and analysis of 127 experimental studies on dimensional quality in ME AM.
• Critical evaluation of machines, materials, sample sizes, artifact designs, and printing parameters.

Main Results:

• Analysis of 127 studies revealed variations in machines (79), materials (ABS 43%, PLA 36%), sample sizes (<40 in 84% of studies), and artifact dimensions.
• Relationships between printing parameters and dimensional quality were often uncertain or contradictory across studies.
• Limited agreement among studies restricts the generalizability of parameter optimization findings.

Conclusions:

• Despite numerous studies optimizing parameters like nozzle gap height and print head velocity, a lack of consensus hinders broad application.
• Recent investigations into the local dimensional variance of deposited single strands show potential for deeper understanding of defects.
• Further research focusing on fundamental material behavior during extrusion is needed to improve dimensional accuracy in ME AM.