Compression of additively manufactured PLA for biomedical applications: Effects of test conditions on properties of solid samples

Abstract

Understanding the mechanical behaviour of additively manufactured (AM) biomedical polymeric devices under various loading regimes is important for tailoring their design to specific applications. This paper presents the results of an experimental study of compressive mechanical properties of AM cubic samples of biocompatible polylactic acid (PLA) manufactured with fused filament fabrication. The measured elastic modulus and ultimate compression strength were compared and analysed for varying testing parameters, such as strain rate and contact friction, for samples with different characteristic sizes. The changes in density of the samples were also assessed for evaluation of the extent of material compaction after deformation. Surface morphology of specimens was examined before and after compression tests using scanning electron and optical microscopy. Different types of defects induced by the manufacturing process and caused by the subsequent compressive deformation were studied and compared. The obtained results are useful for design and optimization of small-size biomedical devices, which require precise control of their structural morphology and mechanical behaviour.

Keywords

• PLA
• Additive manufacturing
• Mechanical properties
• Strain-rate dependence
• Compression
• Contact friction