Tunthawiroon, Phacharaphon
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Tunthawiroon, Phacharaphon
Alternative Name
TUNTHAWIROON, Phacharaphon
Tunthawiroon, P.
Main Affiliation
Email
phacharaphon.tu@kmitl.ac.th
29 results
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Item type:Publication, Characterization of intermetallic phase in as-cast Si-doped Co-Cr-Mo alloys(2019-10-28); Chiba, A.This research aims to investigate the effects of Si concentrations on the microstructure and formation of the intermetallic phase of Co-Cr-Mo-xSi alloys. The Si concentration (x) was varied between 0.1, 0.5, 1.0, 3.0 and 5.0 wt%. The microstructure and intermetallic phase of the solution heat-treated Co-Cr-Mo alloys were characterized using SEM-EDX, XRD and TEM. The microstructure analysis revealed that Si concentration played a role in the evolution of intermetallic phase precipitating in Co-Cr-Mo alloys. Two types of intermetallic phased were found in the Si-doped Co-Cr-Mo alloys. The σ phase was identified in the alloys containing Si between 0.1-1.0 wt% while the increase in Si (3.0-5.0Si) contributed to the formation of the χ phase. The calculated lattice parameters of the intermetallic phase precipitated in the 3.0Si and 5.0Si alloys correlated well with those of Co<inf>5</inf>Cr<inf>3</inf>Si<inf>2</inf> phase. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fabrication and characterization of lightweight aggregates with expanded perlite and NPK nutrient incorporation(2025-06-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effects of Si concentrations on microstructure and mechanical properties of as-cast Co-Cr-Mo alloys(2019-10-28); Chiba, A.This research investigates the effects of different Si concentrations on the microstructure and mechanical properties of Co-Cr-Mo-xSi alloys. The Si concentration (x) was 0.1, 0.5, 1.0, 3.0 and 5.0 wt%. The mechanical properties of the experimental heat-treated Co-Cr-Mo-xSi alloys was determined by hardness and tensile tests. The microstructure was analyzed using SEM. The microstructure analysis revealed that Si concentration played a role in the formation of the intermetallic phase of Co-Cr-Mo-xSi alloys. The presence of the intermetallic phase significantly decreased the ductility of the experimental alloys. However, the hardness was improved and was increased directly proportional to the fraction of the intermetallic phase precipitating in the Co-Cr-Mo-xSi alloys. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of expanded perlite on physical and mechanical properties of cement mortar(2021-09-15); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Corrosion behavior of a Co-Cr-Mo-Si alloy in pure Al and Al-Si melt(2023-01-01); Chiba, AkihikoMetallic phase change materials (MPCMs) are attracting considerable attention for their application in thermal energy storage. Al-Si alloys are considered potential MPCMs; however, to develop storage systems/modules, it is crucial to fabricate corrosion-resistant materials for MPCMs. In this study, the corrosion behavior of Co-28Cr-6Mo-1.5Si (wt%) alloy was examined via immersion tests in commercial Al-Si alloy (ADC12) melt at 700°C for 10 h. The results were compared to those obtained for pure Al. Substrate thickness loss measurements revealed that the liquid metal corrosion was more severe in the Al-Si melt than that in pure Al, suggesting an increased reactivity due to Si addition. Interfacial analysis elucidated a direct reaction between the alloy substrate and molten Al in both cases. Furthermore, the formation of oxides such as Al2O3 and SiO2 did not contribute to corrosion resistance. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Characterization of Fluoride-added Hydroxyapatite Derived from Eggshells for Dental Application(2023-01-01); ; Hydroxyapatite (HA) is one of the potential biomaterials used for treating dental defects. It can be incorporated with fluoride to enhance its anti-caries properties, though other properties could be dependent on processing technique. Hence, this study aims to characterize the influence of sintering on the properties of fluoride-added HA derived from eggshells. FTIR and XRD techniques are used to characterize the chemical and crystal structures of the samples, whilst dissolution test is carried out to characterize material degradation in the acidic environment. The results show that sintering increased the crystallinity in both HA and fluoride-add HA (F-HA) samples, which corresponds with the enhanced stability during the dissolution test. Moreover, it is also found that the addition of fluoride could further stabilize the material structure, though the impurities found in all the samples still need to be minimized. These findings suggest that sintering and fluoride addition could potentially enhance anti-caries properties of eggshell-derived HA, which could be beneficial for dental application in future subject to further process optimization and analysis. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of the Oxide Film on the Performance and Corrosion Resistance of TiNiCu Shape Memory Alloys as the Heat Engine Actuator(2024-10-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Preparation of CdSe thin films: annealing effects on structure and optical properties(2025-01-01); In this work, we prepared well−crystallized CdSe thin films onto glass substrates using vacuum thermal evaporation method (VTE). The CdSe thin film was deposited on the substrate for 10 min in a vacuum chamber where the pressure was maintained at 5⋅10<sup>-5</sup> Torr. To further increase the crystallinity, the as-deposited CdSe films were next thermally annealed in the air at annealing temperatures between 200 and 400 °C. The CdSe films were then investigated for phase composition, morphology, and optical properties. X-ray diffraction (XRD) examinations demonstrated a hexagonal phase of CdSe with preferential orientation along the (002) direction. The morphology analysis showed a homogeneous morphology with an average grain of approximately 65.55–90.25 nm in size. Chemical analysis confirmed the stoichiometric presence of Cd and Se. In addition, the optical band gap, determined from Tauc’s plot, using UV-Vis spectroscopic data, was found to be in the range of 1.66–1.69 eV. An annealing temperature of 300 °C resulted in the most favorable condition with the lowest optical band gap value of 1.66 eV, indicating a narrower band gap in the annealed CdSe thin film. The high deposition rate of VTE presents a significant advantage for this technique, potentially facilitating its use in creating optoelectronics and solar cells that are highly efficient and cost-effective. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancement of Flexural Strength in Fiber–Cement Composites through Modification of Sisal Fiber with Natural Rubber Latex and Expanded Perlite(2024-04-01); Keawprak, NittayaThis study presents a novel approach in enhancing the flexural strength of sisal fiber cement composites by employing a dual coating technique with natural rubber latex and expanded perlite to the sisal fibers. The effects of different fiber content (0.25, 0.5, 0.75, 1, 1.25, and 1.5 wt%) and fiber length (1, 2, and 3 cm) on the physical and mechanical properties of sisal fiber cement were also studied. The physical properties, including bulk density and water absorption, were evaluated via the Archimedes method. Flexural strength was measured using the 3-point bending method, and microstructure was observed using a scanning electron microscope (SEM) and an optical microscope (OM). As the fiber content and length increase, the bulk density of the sisal fiber cement decreases. However, composites utilizing coated fibers consistently exhibit a higher bulk density than those utilizing uncoated fibers, attributed to enhanced adhesion and reduced porosity. The water absorption of sisal fiber cement increases with fiber content, but it is mitigated by the natural rubber latex coating, which prevents fiber–water absorption, and by expanded perlite, which reduces voids in the matrix. Composites containing coated fibers consistently exhibit superior flexural strength compared to those with uncoated fibers. The highest flexural strength values of 5.58 MPa were observed in composites utilizing 3 cm of coated fiber with 0.25 wt% fiber content. Microstructure analysis reveals a well-bonded interface in coated fibers, emphasizing the positive impact of coating on mechanical performance. The incorporation of coated sisal fibers effectively improves adhesion, water resistance, and flexural strength, offering sustainable and durable construction materials. The achieved results can serve as the guidelines for the development of a high-performance bio-based construction materials with improved durability and reduced environmental impact. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optical Properties of CuCdS Thin Film Prepared by Vacuum Thermal Evaporation Technique(2023-01-01); This study reports on the synthesis and characterizations of copper cadmium sulfide (CuCdS) thin films prepared using the vacuum thermal evaporation technique with copper sulfide and CdS as precursors in a 1:1 molar ratio. The structural properties of the thin films were analyzed using X-ray diffraction (XRD) which revealed that the main composition of the thin film was CdS with the preferred orientation of the (101) plane. The optical properties were examined using UV–Vis spectrophotometry. The photosensitivity of the films was determined using I–V measurements performed with a two-probe technique. The prepared CuCdS thin films have high optical transmittance of 92%.2