Investigation of long exposure to accelerated cavitation erosion of polylactic acid parts fabricated by fused deposition modeling

Polymers are supposed to resist cavitation erosion more than metals; however, products fabricated using additive manufacturing have different behavior. In this paper, Polylactic Acid (PLA) fabricated using Fused Deposition Modeling (FDM) was tested in a constraint environment of cavitation erosion. Test specimens were fabricated in layer thickness of 0.3 mm on MakerBot 3D printer. Cavitation erosion experiments were con- ducted using a vibratory cavitation device. The results revealed that the specimens resist cavitation erosion more than that of metals. This can be interpreted and attributed to simultaneous contributors such as porosity, damping effect, water absorption, and roughness. The variation of roughness and morphology with time were verified this result. We increased the test time for several hours; however, we observed a hump formed on the induced area. This hump can be interpreted because of separation of the top layer of the specimen due to shock waves and pitting.