Influence of process interruption on mechanical properties of material extrusion parts

Purpose: This paper aims to identify and quantify the effects of additive manufacturing (AM) process interruption on the tensile strength of material extrusion parts, and to find solutions to mitigate it. Design/methodology/approach: Statistical analysis was performed to compare the tensile strength of specimens prepared with different process interruption time durations and different embedding methods. Subsequently, specimens were reheated at the paused layer before resuming, and tensile strengths were analyzed to observe any improvements. Findings: Process interruption significantly reduced the tensile strength of printed parts by 48 per cent compared to non-interrupted specimens. Reheating the paused layer immediately before resuming the print improved part strength significantly by 47 per cent compared to regular process interrupted specimens and by 90 per cent compared to specimens with embeds. Practical implications: The layer-by-layer deposition of material in AM introduces the capability for in situ embedding of functional components into printed parts. This paper shows that tensile properties are degraded during embedding due to the need for process interruption. These effects can be addressed by reheating the paused layer, providing process guidance for embedding with AM. Originality/value: This paper provides an understanding of process interruption and embedding effects on mechanical properties of the parts, and how to improve them. The results from this experimental analysis provide crucial information toward design guidelines for multi-functional AM with embedded components.