Manufacturing and testing of Bi-material (Wood-PLA/Carbon-PLA) used for structurally integrated engineering application

Abstract

Additive manufacturing (AM) has been effectively employed in numerous applications due to its enhanced properties such as cost reduction, faster fabrication, and less material wastage. Fused filament fabrication (FFF) method is one of the most prevalent AM process broadly used for fabricating complex polymeric parts. Wood filler dispersed inside thermoplastic matrix (Polylactic Acid-PLA) is termed as Wood-PLA. Wood-PLA is widely employed in building constructions, fencing, and other structural applications. Whereas, Carbon-PLA is a thermoplastic polymer composed of carbon fiber and PLA. Due to its high strength, light weight, and durable properties, it is employed in various industries such as automotive, aerospace, and so on. Bi-materials are multi-functional materials, with unique characteristics at different regions of a part. Due to its unique properties, it is used in different integrated structural engineering applications such as defense, aerospace, energy, and safety gears. Bi-material could be fabricated using FFF through varying the filament after depositing few layers. Fabricated Bi-material exhibited mechanical properties such as tensile strength (16.7 ± 0.08 MPa), compressive strength (51.8 ± 3 MPa), flexural strength (72.1 ± 0.15 MPa), and impact energy (0.910 ± 0.02 J). Hardness value of Bi-material is 76.5 shore-D. The coupon studies revealed that Bi-material possesses better mechanical characteristics than Wood-PLA composites and is on par with Carbon-PLA. This work gives an insight into mechanical behavior of Bi-material (Wood-PLA/Carbon-PLA) under various loads. For microscopic examination (under optical microscopy), the sample was treated using acetone and sandpaper for better revelation of bonding of interface and buckling of layer. The brittle morphologies were observed in the fracture surface of failed sample using scanning electron microscope. The outcome of this study would open up opportunities that help in fabricating integrated structure used in engineering applications.