In this study, we introduce a novel flash light sintering (FLS) method to address the issue of secondary phase formation in conventional high-temperature thermal sintering processes. The microstructure and cross section of the Lanthanum strontium cobalt (LSC) air electrode were analyzed using field emission scanning electron microscopy (FE-SEM). The presence of secondary phases was evaluated using X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) in SEM. Electrochemical performance was assessed using NiO-YSZ anode-supported LSC cathode cells at 750oC. The maximum power density of the thermally sintered LSC cathode at 900oC was 272.4 mW/cm², while the flash light sintered LSC cathode by 18.5 J/cm² achieved 2,222 mW/cm². These results demonstrate that the flash light sintering process can effectively prevent secondary phase formation and successfully sinter the electrode, thereby enhancing the performance and reliability of SOFCs.

This study investigated effects of energy levels, pulse durations, and pulse frequencies during an IPL (Intense Pulsed Light) sintering process on surface morphology and resistance of screen-printed Ag patterns on PET substrates. Surface characteristics, including primary profile (Pa), roughness (Ra), thickness, and sheet resistance, were measured before and after sintering. At fixed energy levels (13.18, 32.96, and 46.14 kW), increasing pulse counts (2, 5, and 7) at 6 ms durations significantly increased Pa and thickness, while Ra was not changed. In contrast, higher pulse counts (4, 10, and 14) at 3 ms durations improved surface roughness by reducing Ra. Statistical analysis (Paired T-test) confirmed these results. Sheet resistance analysis showed that lower pulse counts at 6 ms caused greater variability in resistance, stabilizing with higher counts. At 3 ms, surface resistance decreased with higher pulse counts, showing reduced variability. These results suggest that adjusting pulse conditions and counts during the sintering process can optimize both electrical properties and uniformity. Additionally, morphological changes before and after sintering indicated that these adjustments might influence upper-layer printability in multilayer printing. The study highlights the importance of considering both functional and morphological characteristics during sintering for optimized production of printed electronic devices.

The WC-5wt.% TiC compacts, which was fabricated by pulsed current activated sintering process (PCAS), were cryogenically treated to improve the mechanical performance. The densely consolidated specimens were exposed to liquid nitrogen for 6, 12, and 24 h. All cryogenically treated samples exhibited compressive stress in the sintered body compared with the untreated sample. The cryogenically treated samples exhibited significant improvement in mechanical properties, with a 9% increase in Vickers hardness and a 52.6% decrease in the fracture toughness compared with the untreated samples. However, excessive treatment of over 12 h deteriorates the mechanical properties due to tensile stress in the specimens. Therefore, the cryogenic treatment time should be controlled precisely to obtain mechanically enhanced hard materials.

A high temperature sintering process for solid electrolyte is the main cause of the increase in manufacturing costs of SOFCs. In this study, we developed a novel flash light sintering technique as an alternative sintering process of the conventional thermal sintering process. The YSZ electrolyte films were fabricated by conventional screen-printing method and the flash light sintering process and ESB sintering aid were applied to improve the flash light sinterability of the YSZ electrolyte. In the flash light sintering process, the effect of various pulse conditions such as energy density, and pulse interval were investigated and the microstructure, crystallinity, and sintering behavior of the sintered films were analyzed to demonstrate the effectiveness of the flash light sintering process. The flash light sintered YSZ electrolyte layer was used to fabricate the anode-supported SOFCs and its functionality is successfully demonstrated with the high open circuit voltage. The significance of this study includes minimization of the process time from tens of hours to just a few seconds, thus facilitating the commercialization of SOFCs.

Recent developments in additive manufacturing (AM) process have led us to fabricate many mechanical and electrical components or devices into complex geometries. Within existing AM processes, laser is widely used as an energy source to selectively sinter particles with a powder bed fusion (PBF) process or cure photopolymers with a vat photopolymerization (VPP) process. This study investigated the applicability of the SLS process for silver nanoparticles (Ag NPs)-photopolymer inks to fabricate micro-scale conductive patterns. With Ag NPs-photopolymer inks prepared with different mixture ratios and pasted on a polyethylene terephthalate (PET) substrate, a pulse width modulation (PWM) signal-controlled 405 nm laser was applied to these inks to selectively sinter and cure the Ag NPs and the photopolymer simultaneously. The final conductive patterns were obtained after a rinse in ethanol to remove un-sintered and un-cured regions of the inks. Microstructures, thickness profiles, pattern width, electrical resistance, and resistivity of the fabricated patterns were investigated by varying the PWM duty and the laser exposure time. Effects of different numbers of scan lines in the pattern and nanoparticle mixture ratios were also investigated. The proposed method is cost effective and easy with fast patterning capabilities. It will leverage practical advances in AM industries.

Nanoparticle laser sintering is one of the vital technologies in additive manufacturing. Numerous processes such as freeform surfaces or seamless parts have been proposed for the fabrication of complex components, however, the resolution and quality of the processes do not meet the standard necessary for practical applications. Therefore, selective laser sintering is used to fabricate electrode patterns in high-precision manufacturing field. Despite the various advantages, laser sintering process generates defects on the pattern with one of the major contributing factors being the Marangoni flow. In this study, the laser sintering process was used to determine the relationship between the nanoparticle blending conditions and the microstructure of the fabricated electrode pattern through the control of the nanoparticles density and laser characteristics such as power, pulse duration, and scan speed. As a result, the conditions for Marangoni flow were analyzed in relation to the concentration of the nanoparticle solution and laser irradiation parameters. More severe Marangoni flow was produced with the solution having a low weight percent of nanoparticles, while the width of the pattern was uniform when the pulsed laser was applied using a high peak power to achieve the same total amount of energy.

Due to the ever-advancing technology in various production industries, the materials of machined products have been diversified from simple steel materials to composite materials, powder metallurgy materials and silicon. Powder metallurgy materials have excellent mechanical/chemical properties, but have disadvantages such as; difficulty in processing using conventional processing methods, increased processing cost and generation of a large amount of dust. In addition, the need for the development of specialized machine tools increases due to the disadvantages such as the frequent occurrence of burrs in tapping and drilling. In order to solve the problem of machining of high hardness sintered products, a method of maximizing productivity and efficiency by processing the powder metallurgy material before it is completely sintered is being studied. In this study, structural analysis of a turret center for the verification of structural stability of a turret center for processing powder metallurgy materials was carried out. In addition, the shape was optimized to improve the structural stability and weight and presented an optimal model. The study aimed at developing more reliable turret center through the optimized model.

The objective of this study was to investigate wear characteristics of Fe-TiB₂ composites prepared by pressureless sintering (PLS) and spark plasma sintering (SPS) using nanocomposite mixtures. Prior to wear test, micro-structures and mechanical properties of specimens were examined. Wear characteristics of these specimens slid against SiC were assessed using ball-on-disk tribo-tester. Results showed that PLS specimen had significantly large TiB₂ particles in the Fe matrix than SPS specimen. The relatively large TiB₂ particles in PLS specimen might be due to grain growth and coarsening during sintering process. Hardness of SPS specimen was substantially larger than that of PLS specimen. Furthermore, SPS specimen exhibited significantly larger wear resistance than PLS specimen. These differences in hardness and wear resistance between specimens might be associated with differences in their micro-structures. Results of this study provide better understanding of wear characteristics of Fe-TiB₂ composites.

Pressure sensors are widely used in industries, including cars and coolers. Highly accurate pressure sensors are capable of corresponding to changes in the surrounding temperature. Additionally, the manufacturing process of pressure sensors greatly impacts the cost and degree of precision. This study undertook to examine the manufacturing process of pressure sensors, especially those using ceramic diaphragm. Ruthenium oxide (RuO2) was used instead of strain gauge for piezoresistance. TC thermistor (temperature coefficient) resistance compensated for changes in outdoor air temperature. Furthermore, thick-film resistors were precisely adjusted with laser trimming technology. These processes resulted in the production of a high accuracy diaphragm pressure sensor having an ability to correspond to changes in outdoor temperatures.