Interlayer fracture energy of 3D-printed PLA material

The application of 3D printing in additive manufacturing processes is expanding due to its versatility and the progress in the process control. In conjunction with its fast-growing applications, the performance and properties of the material after 3D printing need thorough assessments for critical designs in medical, aerospace, and automotive industries. Although increasing the deposition height in 3D printing decreases the time of manufacturing, the properties of the products must satisfy design specifications for the product strength and surface condition. The objective of the current study is to explore the effect of deposition height on tensile fracture energy of the layered structure of a biodegradable and bioactive thermoplastic polymer, known as polylactide (PLA). The results obtained from uniaxial tensile loading experiments show that the energy required for interlayer fracture is dependent on the deposition height. Based on the experimental results, it is evident that two factors conversely affect the fracture energy: tensile residual stress and the interlayer contact area. Also, the results show that the surface roughness has no significant influence on fracture energy.