A study on the effect of heat treatment temperature on mesophase development in coal tar pitch

2013 ◽  
Author(s):  
Neha Soni ◽  
Raviraj K. Shah ◽  
Rakesh Shrivastava ◽  
Manoj Datar
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Wen-Juan Zhang ◽  
Shi-Hua Song ◽  
Wen-Hong Tian

Coal tar pitch (CTP) is a quite promising candidate for the production of porous carbons. Traditionally, the porous carbons are prepared by the heat treatment of carbon precursors in the presence of template and activator. In this paper, EDTA-Na2Mg•4H2O and CTP were mixed to produce porous carbons in the absence of template and activator, which were generated in situ by the heat treatment of EDTA-Na2Mg•4H2O. The pyrolysis and morphology behavior of the mixture of EDTA-Na2Mg•4H2O and coal tar pitch (EDTA-Na2Mg•4H2O@CTP) were studied by thermogravimetry and differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The characteristics of the obtained porous carbons were characterized by N2 adsorption-desorption isotherm. The results show that EDTA-Na2Mg•4H2O has a great influence on the pyrolysis and morphology of CTP. The pyrolysis behavior of CTP becomes complicated after the addition of EDTA-Na2Mg•4H2O for the physical and chemical changes of EDTA-Na2Mg•4H2O during the heat treatment. EDTA-Na2Mg•4H2O@CTP dehydrates at 160°C and decomposes Na2CO3 and MgO at 600°C. The surface morphology of EDTA-Na2Mg•4H2O@CTP changes with the EDTA-Na2Mg•4H2O content and heat treatment temperature. After acid washing of the product of EDTA-Na2Mg•4H2O@CTP heat-treated at 700°C, the obtained porous carbon material consists of micropores and mesopores. Its specific surface area is 574.18 m2 g−1 and the average pore width is 4.53 nm.


2013 ◽  
Vol 27 (10) ◽  
pp. 1079-1083
Author(s):  
Zhao-Hui LIU ◽  
Gen-Liang HOU ◽  
Xun-Jia SU ◽  
Feng GUO ◽  
Zhou XIAO ◽  
...  

2009 ◽  
Vol 18 (12) ◽  
pp. 935-938
Author(s):  
H. Kobori ◽  
T. Asahi ◽  
Y. Yamasaki ◽  
A. Sugimura ◽  
T. Taniguchi ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.


2013 ◽  
Vol 747-748 ◽  
pp. 497-501
Author(s):  
Na Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Hua Yuan ◽  
Wen Yong Xu ◽  
...  

Powder metallurgical TiAl alloy was fabricated by gas atomization powders, and the effect of heat treatment temperature on the microstructure evolution and room tensile properties of PM TiAl alloy was investigated. The uniform fine duplex microstructure was formed in PM TiAl based alloy after being heat treated at 1250/2h followed by furnace cooling (FC)+ 900/6h (FC). When the first step heat treatment temperature was improved to 1360/1h, the near lamellar microstructure was achieved. The ductility of the alloy after heat treatment improved markedly to 1.2% and 0.6%, but the tensile strength decreased to 570MPa and 600MPa compared to 655MPa of as-HIP TiAl alloy. Post heat treatment at the higher temperature in the alpha plus gamma field would regenerate thermally induced porosity (TIP).


2015 ◽  
Vol 658 ◽  
pp. 14-18
Author(s):  
Tanaporn Rojhirunsakool ◽  
Duangkwan Thongpian ◽  
Nutthita Chuankrerkkul ◽  
Panyawat Wangyao

Nickel-base superalloys have been used as high temperature materials in land-base gas turbine application. When subjected to long term, high temperature service, large crack propagation was observed. Typical refurbishment method of these turbines is carried out by using TIG welding followed by post-weld standard heat treatment. However, new crack initiation is found in the heat-affected zone after TIG welding. Pre-weld heat treatment has been discovered to improves final γ + γ’ microstructure. This study focuses on the effect of pre-weld heat treatment temperature on final γ + γ’ microstructure. Seven different conditions of pre-weld heat treatment temperature were investigated. Scanning electron microscopy studies were carried out after pre-weld and post-weld heat treatments to compare the γ + γ’ microstructure and capture microcracks. The best pre-weld heat treatment temperature produces uniform distribution of finely dispersed γ’ precipitates in the γ matrix without post-weld crack.


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