scholarly journals The Influence of the Precipitation Heat Treatment Temperature on the Metallurgical, Microstructure, Thermal Properties, and Microhardness of an Alpha Brass

2018 ◽  
Vol 09 (04) ◽  
pp. 440-454 ◽  
Author(s):  
Ignacio Rojas-Rodríguez ◽  
Alberto Lara-Guevara ◽  
Mauricio Salazar-Sicacha ◽  
Julio Cesar Mosquera-Mosquera ◽  
Minerva Robles-Agudo ◽  
...  
Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1403 ◽  
Author(s):  
Lifen Tong ◽  
Xiting Lei ◽  
Guangyao Yang ◽  
Xiaobo Liu

A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN–OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN–OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN–OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 °C to 203.6 °C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN–OH films. Moreover, because of the excellent adhesive property of PEN–OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN–OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN–OH has potential applications in the electronic field.


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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