Characterization of PA‐12 specimens fabricated by projection sintering at various sintering parameters

Abstract

Large area projection sintering (LAPS) promises to be a new method in the field of additive manufacturing. Developed in the Mechanical Engineering Department, University of South Florida, LAPS uses long exposure times over a broad area of powder to fuse into dense, reproducible materials. In contrast, LS, a common powder‐based additive manufacturing, uses a focused beam of light scanned quickly over the material. Local regions of concentrated high‐energy bursts of light lead to higher peak temperatures and differing cooling dynamics and overall crystallinity. The mechanical properties of laser sintered specimens suffer because of uneven particle fusion. LAPS offers the capacity to fine‐tune fusion properties through enhanced thermodynamic control of the heating and cooling profiles for sintering. Further research is required to identify the relationship between LAPS build settings and part properties to enable the fabrication of custom parts with desired properties. This study examines the influence of LAPS sintering parameters on chemical structures, crystallinity, mechanical, and thermal properties of polyamide‐12 specimens using powder X‐ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, small‐angle X‐ray scattering, scanning electron microscopy, and microhardness testing. It was observed that higher crystallinity was imparted to specimens that were sintered for a shorter time and vice versa.

On the effect of irradiance on dimensional accuracy in multijet fusion additive manufacturing

“…This finding demonstrates that the higher amount of energy provided through irradiance determines a decrease of crystallinity degree, according to results reported in the body of literature for LS, SIS and LAPS (Negi and Sharma, 2016; Rajamani et al , 2018; Kaur et al , 2021).…”

“…Kaur et al investigated the role of energy density in large area projection sintering (LAPS). Their results highlighted that the crystallinity degree of parts increases when the amount of energy decreases, namely, when lower temperature and exposure time are adopted (Kaur et al , 2021).…”

Efficient Electromagnetic Interference Shielding of PPA6@NiM/PDMS Composites with Porous and Asymmetric Gradient Structures

“…As the proportion of the poor solvent increases, the mixed solution reaches the critical saturation concentration. There is no interaction between PA6 and PVP, which precipitates out of the solution through a phase-separation process. ,, …”

“…There is no interaction between PA6 and PVP, which precipitates out of the solution through a phase-separation process. 24,30,31 Figure 3a−d shows the microstructure of PPA6 microspheres after nickel plating. The PPA6@NiM prepared under the four electroless nickel plating formulations maintained good dispersibility without sticking.…”

Optimizing the mechanical properties of TiO2/PA12 nano‐composites fabricated by SLS 3D printing

“…[6,7] In the SLS process, polymers are the most commonly used materials owing to high accuracy of sintered parts, low consumption of sintering laser power, and low processing temperature of the polymers. [8,9] The most widely applied polymer in the SLS process is Polyamide (PA), which is due to its good processability, high thermal stability, and excellent mechanical properties. [10][11][12][13] However, the addition of nano-particles into PA12 matrix can improve the mechanical properties of this polymer, because the nanoparticles have a high specific surface area that can act as a stress-transfer interface.…”