Narrow Results

The relaxation property of sodium silicate $({\mathrm{\text{Na}}}_2{\mathrm{\text{SiO}}}_3)$ (SS) was investigated by complex impedance spectroscopy (CIS) in a wide range of frequency (100kHz–5MHz) and temperature $(50^{\circ }\mathrm{\text{C}}\text{–}450^{\circ }\mathrm{\text{C}})$. Orthorhombic crystal phase was synthesized by a sintering process. The CIS study shows high complex impedance in low-frequency region due to strong dispersion and controls the relaxation mechanism of ions or cations in the crystal lattice. A decrease of the energy loss $(tan\delta )$ occurs with increasing frequency for all temperatures showing the normal behavior of SS. Relaxation time was calculated using the dielectric functions $Z^{\prime \prime }(\omega )$ and $M^{\prime \prime }(\omega )$. The temperature dependent relaxation plot follows the Arrhenius law, where the slope represents the activation energy.

Sintering of binder jet 3D printed (BJ3DP) parts results in significant nonlinear distortion with typical shrinkage value of 5–20%, which makes design for BJ3DP and post-machining difficult. In this work, a computational modeling framework with calibration and validation procedure is developed to simulate distortion during sintering of BJ3DP parts accurately for the first time. The computational model employs the finite element analysis with a viscoplastic constitutive model that accounts for effects of gravity and friction. A calibration procedure is proposed to obtain values of different model parameters systematically through dilatometric, gravity bending, and grain growth experiments. For model validation, four bridges with different spans and a second part with a circular hole and two free overhangs are designed. The calibration procedure is applied to develop a computational model for sintered 316L stainless steel BJ3DP parts. The displacements at various locations on the sintered parts are simulated using the calibrated model and are found to have errors less than 3.5% compared to those obtained by experiment.

This study aims to explain the dielectric relaxation in sodium silicate (Na2SiO3) and its direct dependence on temperature across various frequencies. The study examines and elucidates the involvement of various types of polarization in the thermo-active dielectric relaxation process. Both low-frequency dielectric dispersion and complex impedance play pivotal roles in controlling the thermo-active dielectric relaxation process. Utilizing complex data plots, the study actively, and prominently illustrates the relaxation process.