Tunthawiroon, Phacharaphon

Preferred name

Alternative Name

TUNTHAWIROON, Phacharaphon

Tunthawiroon, P.

Main Affiliation

School of Engineering

phacharaphon.tu@kmitl.ac.th

Now showing 1 - 10 of 20

Some of the metrics are blocked by your
consent settings
Optical Properties of CuCdS Thin Film Prepared by Vacuum Thermal Evaporation Technique
(2023-01-01)
Hankoy, Montree
;
Treetornkeerati, Paramapat
;
Fungfuang, Natasia
;
Khlayboonme, S. Tipawan
;
Kitiwan, Mettaya
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%.
Some of the metrics are blocked by your
consent settings
Possibility of metallic cobalt formation in the oxide scale during high-temperature oxidation of Co-27Cr-6Mo alloy in air
(2023-01-01)
Wongpromrat, Patthranit
;
Tunthawiroon, Phacharaphon
;
Bumrungthaichaichan, Eakarach
;
Ponpo, Phisan
;
Nilsonthi, Thanasak
Co-based alloys are known to be high oxidation-resistant material and used in several high temperature applications. During high temperature oxidation, duplex oxides containing Co and Cr were formed. It was thermodynamically elucidated that when the growing scale was thick enough, the partial pressure of O<inf>2</inf> in the scale dropped. Then, the reduction of CoO occurred for promoting O<inf>2</inf> which was responsible for Cr<inf>2</inf>O<inf>3</inf> production. This work experimentally proved this point by in situ char-acterising Co-27Cr-6Mo at high temperatures in air by X-ray diffractometer in a grazing incident mode and metallic Co was confirmed to be formed by the reduction of CoO consistent with the image taken and analysed by field emission scanning electron microscope, energy-dispersive X-ray, and electron backscatter diffraction. Furthermore, the change in lattice parameter and the phase transition were observed when the temperature was altered.
Some of the metrics are blocked by your
consent settings
Fabrication and characterization of lightweight aggregates with expanded perlite and NPK nutrient incorporation
(2025-06-01)
Rungrueng, Panadda
;
Hankoy, Montree
;
Kitiwan, Mettaya
;
Keawprak, Nittaya
;
Tunthawiroon, Phacharaphon
This study focuses on the development of porous lightweight aggregates incorporated with NPK fertilizer as a sustainable nutrient carrier for agricultural applications. The integration of expanded perlite (EP) as a pore-forming agent enabled the production of lightweight aggregates (EP-LWAs) at lower sintering temperatures (900 °C) while maintaining high porosity and water absorption properties, reducing energy consumption compared to conventional high-temperature ceramic processing. The optimized EP-LWAs exhibited a bulk density of 1.15 g/cm3, porosity of 46.09 %, and water absorption of 40.28 %, ensuring enhanced nutrient retention capacity. The fertilizer incorporation process was achieved using a simple vacuum infiltration technique, effectively loading the pellets with 1.2 % nitrogen (N), 2.6 % phosphorus (P), and 1.2 % potassium (K), surpassing typical soil nutrient levels and exhibiting comparable NPK content to organic fertilizers. These results highlight the potential of EP-LWAs as an energy-efficient and eco-friendly planting materials, offering a cost-effective for sustainable agriculture, green roof, and vertical gardening applications.
Some of the metrics are blocked by your
consent settings
Modification of Al2O3-Based Membranes with Carbon Black for Enhanced Hydrogen Permeation
(2025-11-01)
Hankoy, Montree
;
Rodchom, Mana
;
Vichaphund, Supawan
;
Atong, Duangduen
;
Zhang, Jianfeng
This work presents the development and characterization of alumina–carbon black (ACB) composite membranes for enhanced hydrogen separation performance. A series of membranes containing 0–3.0 wt.% carbon black was fabricated via high-temperature sintering and systematically investigated with respect to their structural, morphological, mechanical, and gas separation properties. The addition of carbon black significantly influenced membrane microstructure, promoting pore network formation, increasing specific surface area, and enhancing gas transport. Gas permeation tests using H<inf>2</inf> and N<inf>2</inf> revealed that all ACB membranes exhibited higher hydrogen permeance than the pure Al<inf>2</inf>O<inf>3</inf> membrane. Notably, the ACB3.0 specimen demonstrated the highest H<inf>2</inf> permeance of 508 × 10−6 mol m−2 s−1 Pa−1 at 303 K, which is nearly four times greater than the unmodified membrane. At an elevated temperature (773 K), H<inf>2</inf>/N<inf>2</inf> selectivity improved with increasing carbon black content, with ACB3.0 achieving a maximum selectivity of 3.82, exceeding the theoretical Knudsen value, suggesting a synergistic contribution of Knudsen diffusion and surface diffusion. These results demonstrate that carbon black is a cost-effective and versatile additive for modifying ceramic membranes, offering a promising route for advancing hydrogen purification technologies in industrial applications.
Some of the metrics are blocked by your
consent settings
Characterization of oxide films on wrought Co–Cr–Mo–xSi alloys exposed to high-temperature oxidation
(2021-10-01)
Tunthawiroon, Phacharaphon
;
Kitiwan, Mettaya
;
Srirussamee, Kasama
;
Li, Yunping
;
Yamanaka, Kenta
Co-based alloys are currently being used in a wide range of high temperature applications owing to their high resistance to oxidation and corrosion. However, their oxidation-induced degradation could still occur during the long-term exposure to high temperature. Thus, the continuous development of oxidation-resistant Co-based alloys is of crucial importance. In this research, the influence of Si addition on the oxidation behavior of Co–Cr–Mo–xSi alloys under the isothermal oxidation treatment at 700 °C in air was investigated. The Si concentration (x) was varied from 0.1 to 5.0 wt.%. Surface morphologies and chemical compositions of the oxide films formed were analyzed by using SEM-EDS and XPS. The chemical compositions obtained from the surface analysis revealed that Si has played a role in the stabilization of Cr oxides on the surface of Co–Cr–Mo–xSi alloys. With increasing Si concentration, Co-oxide formation on the alloy surface was suppressed by the presence of Cr-oxide due to the selective oxidation of Cr atoms. Furthermore, SiO<inf>2</inf> was both found along the grain boundaries and interfaces between the outmost oxide layer and matrix. It was also found that the oxide thickness was reduced with increasing Si concentration. This was a result of the formation of stable Cr-oxide and SiO<inf>2</inf> sub-layer that became a barrier inhibiting the inward and outward diffusion of O and Cr.
Some of the metrics are blocked by your
consent settings
Evidence for chromium, cobalt and molybdenum volatilisations during high temperature oxidation of Co-27Cr-6Mo Alloy
(2022-07-01)
Wongpromrat, Patthranit
;
Galerie, Alain
;
Thublaor, Thammaporn
;
Chandra-ambhorn, Walairat
;
Ponpo, Phisan
A Co-27Cr-6Mo alloy was oxidised in pure O<inf>2</inf> between 800 and 1000 °C for durations up to 96 h. The flow rate was varied between 2 and 5 cm.s–1. In these conditions, volatilisations of chromium, cobalt and molybdenum were observed. The chromium volatilisation values were in good agreement with calculations assuming (CrO<inf>3</inf>)g volatilisation limited by diffusion in the gas boundary layer. On the contrary, the measured flux of evaporated Co was higher than the calculated Co volatilisation flux from the metallic Co. The theoretical relation between the solid Co particle size and its vapour pressure was suggested to help explaining such difference.
Some of the metrics are blocked by your
consent settings
A STUDY ON SiC SUSCEPTOR CONFIGURATION FOR MICROWAVE HYBRID HEATING
(2023-01-01)
Ngamkiatpaisan, Akawat
;
Hankoy, Montree
;
Kitiwan, Mettaya
;
Keawprak, Nittaya
;
Tunthawiroon, Phacharaphon
Microwave hybrid heating (MHH) is a novel method to enhance ceramic sintering at high temperatures. The heating mechanism by MHH involves two directions of heat transfer for materials: microwaves heat the sample from the inside out, while the susceptor provides conventional heating from the outside. This unique heating mechanism offers several advantages, including uniform heating, rapid sintering, and enhanced microstructure and properties of materials. This study investigates the configuration of silicon carbide (SiC) susceptors for microwave hybrid heating. The microwave oven (multi-mode, 2.45 GHz, 1.2 kW) was modified with a ceramic insulator housing to maintain the temperature in the chamber. The effects of different configurations of SiC susceptors and microwave powers on the heating rate and maximum temperature were investigated. SiC susceptor plates were placed in the microwave oven using 3 different configurations, and for each condition, the microwave power was varied at 40, 60, 80, and 100% (480, 720, 960, and 1,200 W). The temperature in the microwave chamber was recorded until it reached 900°C or after 30 min of heating. Using two plates of SiC susceptor at 100 % power resulted in the highest heating rate of 62°C/min to reach 925°C. The results of this study offer guidance for the selection of appropriate heating conditions for individual ceramic materials, which can lead to more effective sintering processes.
Some of the metrics are blocked by your
consent settings
Influence of Expanded Perlite on Pore Structure and Physical Properties of Lightweight Aggregates Derived from Red Clay
(2026-05-01)
Moolpradab, Paniti
;
Hankoy, Montree
;
Zhang, Jianfeng
;
Keawprak, Nittaya
;
Kitiwan, Mettaya
The utilization of locally sourced raw materials for lightweight aggregate (LWA) production has attracted increasing attention due to its potential for cost reduction and sustainable material development. This study investigates the effect of expanded perlite addition (10–40 wt%) on the physical, structural, and mechanical properties of LWAs derived from In Buri red clay, sintered at a relatively low temperature of 800 °C without a conventional high-temperature bloating process. X-ray diffraction (XRD) analysis revealed that quartz remained the dominant phase after sintering, with minor albite and residual illite, indicating limited phase transformation. Thermal analysis showed that major mass loss occurred below 600 °C, confirming that 800 °C is sufficient for removing volatile components. SEM observations demonstrated that increasing perlite content led to the development of a more porous and interconnected microstructure. As the expanded perlite content increased, the bulk density decreased from 1.31 to 0.80 g/cm3, while the apparent porosity and water absorption increased to 48.5% and 60.8%, respectively. Conversely, crushing strength decreased due to increased porosity. These results demonstrate that expanded perlite is an effective additive for tailoring the microstructure and performance of LWAs at low sintering temperature. The developed materials show strong potential for horticultural applications.
Some of the metrics are blocked by your
consent settings
Comparative study of vacuum arc-remelting and spark plasma sintering processes on microstructure and corrosion behavior of Cp-Ti for biomedical implant applications
(2025-11-01)
Kunbuala, Neeraphat
;
Srirussamee, Kasama
;
Phamornnak, Chinnawich
;
Tunthawiroon, Phacharaphon
;
Hankoy, Montree
Titanium (Ti) and its alloys are widely used for biomedical applications due to their excellent mechanical properties and biocompatibility. However, the selection of an appropriate manufacturing process is critical to ensuring the optimal performance of Ti-based implants. This study investigates the effects of two fabrication methods –vacuum arc remelting (VAR) and spark plasma sintering (SPS) – on the microstructure and corrosion behavior of commercially pure titanium (Cp-Ti). VAR-Ti ingots were fabricated using arc-melting with multiple remelting cycles, whereas SPS-Ti specimens were sintered from Ti powders under pressure and pulsed current in a high-vacuum environment. Both specimens were subsequently heat-treated at 800 °C and furnace cooled. Microstructural characterization revealed coarser grains and porosity in VAR-Ti, while SPS-Ti showed refined, uniform α-phase structures. Electrochemical tests, including OCP, polarization, EIS, and ICP-MS, indicated slightly enhanced corrosion resistance in SPS-Ti, attributed to its defect-free microstructure. XPS analysis confirmed TiO<inf>2</inf> surface formation on both samples. Additionally, both materials exhibited high ductility and excellent biocompatibility, with cell viability exceeding ISO 10993-5 thresholds. These findings highlight the advantage of SPS in producing defect-minimized Cp-Ti with improved corrosion behavior for biomedical applications.
Some of the metrics are blocked by your
consent settings
A study on wettability and formation of intermetallic phase between Co–Cr–Mo alloy and Sn-Solder used as a potential under bump metallization for flip-chip packages
(2020-10-01)
Kyaw, Tin Tin
;
Tunthawiroon, Phacharaphon
;
Kanlayasiri, Kannachai
;
Yamanaka, Kenta
;
Chiba, Akihiko
The wettability and formation of intermetallic compounds (IMCs) formed between a Co–Cr–Mo-based alloy and Sn-solder metal were investigated using the reflow soldering method. Soldering was conducted in an electric furnace in separate experiments at temperatures of 533, 553, 573, 623, and 673 K for 600 s. The morphology of the intermetallic layer formed at the Co–Cr–Mo-based/Sn-solder interface was characterized by scanning electron microscopy (SEM). The chemical composition and phase of the formed intermetallic layer were analyzed by electron probe microscopic analysis (EPMA) and X-ray diffraction analysis. Wettability analysis indicated that the soldering temperature influenced the wettability. With increasing soldering temperatures, the spreading factor increased, whereas the contact angle decreased. The intermetallic layers were found in triples in the intermediate zone between the solidified Sn-solder and the Co–Cr–Mo-based substrate. The thickness of the intermetallic layers increased in proportion with increasing soldering temperature. The EPMA analysis indicated only two IMCs formed at the interface of the joint at all of the investigated soldering temperatures, although three interfacial layers were observed by SEM analysis. The Sn-richer phase, Co(Cr,Mo)Sn<inf>2</inf>, formed adjacent to the Sn-solder matrix, whereas the Co(Cr,Mo)Sn was found near the Co–Cr–Mo-based substrate. The nanoindentation measurement revealed that the formed Co(Cr,Mo)Sn<inf>2</inf> and Co(Cr,Mo)Sn IMCs possessed lower hardness values compared to the Sn–Cu intermetallic systems.

Tunthawiroon, Phacharaphon

Filters

Settings

Sort By

Results per page