Fabrication and mechanical behavior of structurally graded material (ceramic-reinforced polylactic acid/polylactic acid) for integrated engineering application

The goal of this study is to provide first-hand knowledge to the industrial community on the mechanical properties of structurally graded materials (polylactic acid/ceramic-reinforced polylactic acid) wall fabricated through fused filament fabrication. Structurally graded materials are inhomogeneous materials that consist of two or more materials to produce a final structure with distinctive material properties. Because of their specific gradient, structurally graded materials are commonly used in various applications such as aerospace, medicine, optoelectronics, biotechnology, etc. These applications have certain requirements and significant properties such as thermo-mechanical resistance and chemical stability. Filaments of polylactic acid were deposited over ceramic-reinforced polylactic acid to fabricate structurally graded material walls. Coupon studies revealed that structurally graded materials exhibited mechanical properties (tensile strength: 19.1 +/- 0.3 MPa, flexural strength: 100.1 +/- 0.23 MPa, compressive strength: 64.6 +/- 2.35 MPa, impact energy: 1.32 +/- 0.038 J, and hardness: 81.5 Shore-D) that are better than polylactic acid. It is revealed that structurally graded materials possess better mechanical properties than polylactic acid and exhibit behavior similar to ceramic-reinforced polylactic acid. Fracture morphology indicates the occurrence of brittle fracture in tensile sample.