Mode I and II fracture toughness investigation of Laser-Sintered Polyamide
Emanoil Linul, Liviu Marșavina, Dan Ioan Stoia
Abstract
This paper presents experimental investigations on the geometrical and fracture properties of specimens obtained by Additive Manufacturing technology. The experimental tests were performed on Single Edge Notch Bend (SENB) specimens obtained through the Selective Laser Sintering process, based on the polyamide PA2200 material. The SENB specimens were manufactured using three different process energies-PEs (E1, E2 and E3), respectively three different spatial orientations-SOs (Vertical-V, Horizontal-H and Oblique-O). Symmetric and asymmetric four-point bending tests were used to determine the mode I and II fracture toughness (KIC and KIIC). It was observed that the density (ρ) of the 3D printed specimens is highly dependent on the PE and SO, the highest density values being obtained for the highest PE (E1), respectively for the V-SO. Maximum relative errors of the main geometrical parameters (thickness, length and width) of the SENB specimens were obtained for E3-PE and H-SO. With respect to the fracture toughness, it was observed that, regardless of PE and SO, the KIC values are higher than KIIC ones. The highest KIC value was found for E1 and V-SO, while KIIC highlight the highest value for E1 and H-SO. Finally, analysis of variance (ANOVA) method is used to analyze the influence of various factors on outcome parameters.