Exploring mixed-mode fracture behavior and mechanical properties of selective laser sintered polyamide 12 components

• Published in: Rapid prototyping journal 2024-02, Vol.30 (3), p.529-546
• Main Authors: Zehir, Burçak, Seyedzavvar, Mirsadegh, Boğa, Cem
• Format: Article
• Language: English
• Subjects: Design optimization; Failure mechanisms; Finite element method; Fracture mechanics; Fracture testing; Fracture toughness; Injection molding; Investigations; J integral; Laser sintering; Manufacturing; Mechanical properties; Modulus of elasticity; Orientation; Polyamide resins; Polymers; Rapid prototyping; Raw materials; Scanning electron microscopy; Stress intensity factors; Temperature; Tensile properties; Tensile strength; Thickness
• ISSN: 1355-2546; 1758-7670; 1355-2546
• DOI: 10.1108/RPJ-08-2023-0270

Purpose This study aims to comprehensively investigate the mixed-mode fracture behavior and mechanical properties of selective laser sintering (SLS) polyamide 12 (PA12) components, considering different build orientations and layer thicknesses. The primary objectives include the following. Conducting mixed-mode fracture and mechanical analyses on SLS PA12 parts. Investigating the influence of build orientation and layer thickness on the mechanical properties of SLS-printed components. Examining the fracture mechanisms of SLS-produced Arcan fracture and tensile specimens through experimental methods and finite element analyses. Design/methodology/approach The research used a combination of experimental techniques and numerical analyses. Tensile and Arcan fracture specimens were fabricated using the SLS process with varying build orientations (X, X–Y, Z) and layer thicknesses (0.1 mm, 0.2 mm). Mechanical properties, including tensile strength, modulus of elasticity and critical stress intensity factor, were quantified through experimental testing. Mixed-mode fracture tests were conducted using a specialized fixture, and finite element analyses using the J-integral method were performed to calculate fracture toughness. Scanning electron microscopy (SEM) was used for detailed morphological analysis of fractured surfaces. Findings The investigation revealed that the highest tensile properties were achieved in samples fabricated horizontally in the X orientation with a layer thickness of 0.1 mm. Additionally, parts manufactured with a layer thickness of 0.2 mm exhibited favorable mixed-mode fracture behavior. The results emphasize the significance of build orientation and layer thickness in influencing mechanical properties and fracture behavior. SEM analysis provided valuable insights into the failure mechanisms of SLS-produced PA12 components. Originality/value This study contributes to the field of additive manufacturing by providing a comprehensive analysis of the mixed-mode fracture behavior and mechanical properties of SLS-produced PA12 components. The investigation offers novel insights into the influence of build orientation and layer thickness on the performance of such components. The combination of experimental testing, numerical analyses and SEM morphological observations enhances the understanding of fracture behavior in additive manufacturing processes. The findings contribute to optimizing the design and manufacturing of high-quality PA12 componen