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Materials Science and Engineering

Chulalongkorn University

Heat treatment

Publication Year

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Full-Text Articles in Engineering

Effect Of Heat Treatment On Phase Transformation Of Tio2 And Its Reflectance Properties, K Archaapinun, N Witit-Anun, P Visuttipitukul Dec 2013

Effect Of Heat Treatment On Phase Transformation Of Tio2 And Its Reflectance Properties, K Archaapinun, N Witit-Anun, P Visuttipitukul

Journal of Metals, Materials and Minerals

Titanium dioxide (TiO2) anti reflection coating film applied for solar cell application, gains more interest due to the insufficient energy problems today. Titanium dioxide can be found in several forms, and the most stable phase is rutile. This research aims to study effect of heat treatment on phase transformation of TiO2 and its effect on reflectance property. Titanium dioxide film was coated on silicon wafer by DC magnetron sputtering to obtain 190 nm and 420 nm thicknesses. Then, it was heat treated at 900C for 1 and 4 hours under ambient atmosphere. Phases and surface morphologies before and after heat …


Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara Jul 2012

Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara

Journal of Metals, Materials and Minerals

Hypoeutectic 26 wt% Cr cast irons without and with Mo were prepared in order to investigate their abrasion wear resistance. The annealed specimens were hardened from 1323 K (As-H) and then tempered at three levels of temperatures between 673 and 823 K for 7.2ks, the temperature giving the maximum hardness (HTmax), lower temperature than that at HTmax (L-HTmax ) and higher temperature than that at HTmax (H-HTmax). The abrasive wear resistance was evaluated using Rubber Wheel abrasion test (three-body-type). It was found that hardness and volume fraction of retained austenite (V) in the heat-treated specimens varied with the Mo content …


An Investigation Of Microstructural Change Of Low Alloy Steel Aisi 4150 By Seebeck Coefficient, T Samran, P Termsuksawad Jul 2010

An Investigation Of Microstructural Change Of Low Alloy Steel Aisi 4150 By Seebeck Coefficient, T Samran, P Termsuksawad

Journal of Metals, Materials and Minerals

Low alloyed steels, whose hardness can be modified by heat treatment, have been widely used in various applications. After heat treatment, they are normally destructively characterized and tested by many approaches via optical microscope and hardness testing. It is useful to develop a non-destructive method relating to its properties and microstructures. The proposed non-destructive approach in this study is the Seebeck coefficient measurement. The materials in this study were carbon steels AISI 4150 rod with a diameter of 1.3 cm and length of 3 cm. The specimens were heat-treated at 900ºC for 1 hour and were then cooled to room …


Effect Of K2o/Sio2 Ratio On The Crystallization Of Leucite In Silicate-Based Glasses, P Sooksaen, J Boonmee, C Witpathomwong, S Likhitlert Jul 2010

Effect Of K2o/Sio2 Ratio On The Crystallization Of Leucite In Silicate-Based Glasses, P Sooksaen, J Boonmee, C Witpathomwong, S Likhitlert

Journal of Metals, Materials and Minerals

Leucite-based glass-ceramics were prepared by controlled crystallization of suitable glass compositions to give required crystalline phase/s. Three glass batches in the system SiO2 - K2O - NaO2 - Al2O3 - TiO2 - CaO were prepared by varying K2O/SiO2 ratio, then melted and quenched. Glasses were characterized for onset of crystallization temperatures by differential thermal analysis (DTA), and heat treatments were carried out from 850 - 1000°C for 4 hours for controlled crystallization of leucite phase. Physical, chemical and crystal structure characterizations were carried out using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). XRD found …


The Effect Of Long-Term Thermal Exposure At Elevated Temperatures On Microstructures And Mechanical Properties In Centrifugally Casted Iron-Base Alloy, G Lothongkum, N Thaweepornkhasemsukh, P Wangyao Dec 2006

The Effect Of Long-Term Thermal Exposure At Elevated Temperatures On Microstructures And Mechanical Properties In Centrifugally Casted Iron-Base Alloy, G Lothongkum, N Thaweepornkhasemsukh, P Wangyao

Journal of Metals, Materials and Minerals

This work has an aim to study and investigate the relationship between high temperature exposure conditions on microstructural evolution and mechanical properties in the iron-based alloy, Fe-30.8 Ni - 26.6 Cr alloy, strengthened by carbide precipitation. Two exposure temperatures (900 and 1000°C) with various thermal exposure times are introduced to the as-received alloy. After short-term exposure, it was found that the secondary carbides precipitated early near the primary carbides, which were chromium and niobium/titanium carbide networks. The secondary carbide precipitations were also found in the dendrite cores. The amounts of needle-like carbides and secondary carbide films increased with time and …