Thermal history based prediction of interlayer bond strength in parts manufactured by material extrusion additive manufacturing

Article; Early Access

关键词: THERMOGRAPHY;   

DOI  :  10.1007/s00170-023-11364-7

来源: SCIE

【 摘 要 】

Material extrusion additive manufacturing, also known as fused filament fabrication (FFF), is currently one of the most widely used technologies. Although promising, the technology is prone to several defects including poor surface quality, low dimensional accuracy, and inadequate mechanical performance caused by weak bonds between successively deposited layers. Studies have shown that bonding between filaments forms above the material's glass transition temperature which makes it essential to study the thermal history of the printing process. Since interlayer bonding is thermally driven, this study has focused on the development of a regression model to predict the average interlayer bonding strength of a part using the thermal history of the printed layers and the process parameter settings. The process parameters studied are deposition temperature, print speed, and layer thickness. This study relies on using finite element analysis (FEA) to obtain the part's thermal history and scanning electron microscopy (SEM) to evaluate the bond quality by performing microstructure analysis. The average interlayer bond strength was assessed by measuring the interlayer bond widths and average weld times of all layers in a printed part. The weld time is the time that the temperature of an extruded filament stays above the glass transition temperature when reheated by an adjacent layer. This study includes experimental validation of the developed predictive models to estimate the average weld time and average bond strength of thin wall samples. Results show that the average bond strength is most significantly influenced by two key variables-the average weld time and layer thickness.

【 授权许可】

Free