Investigation on Electrochemistry Behavior of Fe-Cr-Ni Alloy in Caustic Solution

2014 ◽  
Vol 941-944 ◽  
pp. 1402-1405
Author(s):  
Qi Lei Sun ◽  
Ze Rui Liu ◽  
Ji Liang Liu ◽  
Chong Fang ◽  
Qing Nan Zhang
Keyword(s):  
High Temperature ◽  
Anodic Dissolution ◽  
Anodic Polarization ◽  
Surface Passivation ◽  
Caustic Solution ◽  
Passivation Film ◽  
Ni Alloy ◽  
Inconel 690 ◽  
The Stability ◽  
Electrochemistry Behavior

Electrochemistry experiments such as polarization curve and alternating-current impedance are adopted to study the electrochemistry behavior of Fe-Cr-Ni alloy (Inconel 690 alloy) in the caustic solution of 50% NaOH +0.3%SiO2+0.3%Na2S2O3. The results show that Inconel 690 alloy appears two anodic passivation areas, the passivation of the alloy elements Cr and Ni mainly contributes to the lower potential passivation area and the higher potential passivation area is mainly attributed to the passivation effect of the alloy elements Fe and Ni, especially the later. When Na2S2O is added into the high-temperature caustic solution, it can accelerate the anodic dissolution of Inconel690 alloy, retard or impede its passivation and decrease the stability of the surface passivation film, which is mainly attributed to the effect of Na2S2O3 on the anodic polarization behavior of Ni.

Thermal Expansion Behaviour of Inconel-690 by In Situ High Temperature X-Ray Diffraction

2015 ◽  
Vol 830-831 ◽  
pp. 367-370 ◽  
Author(s):  
D. Ramachandran ◽  
A.M. Kamalan Kirubaharan ◽  
Arul Maximus Rabel ◽  
P. Kuppusami
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Exposure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Temperature Range ◽  
High Temperature Xrd ◽  
Inconel 690 ◽  
The Stability

Ni-Cr-Fe based alloy Inconel 690 is widely used in power plant, marine, chemical and nuclear applications due to its excellent mechanical properties, resistance to thermal creep deformation, good thermal stability and resistance to corrosive and oxidizing environments. In order to study the microstructure of the alloy and the precipitates formation during thermal exposure, the alloy was subjected to in-situ high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1273K. Results of high temperature XRD patterns show (111), (200), (220) and (311) reflections confirming the stability of fcc structure in the temperature of investigation. With increase in the temperature, a shift in peak positions towards lower 2θ values due to lattice expansion was noticed. The average thermal expansion coefficient (TEC) of the alloy increased from 1.33 x 10-5 K-1 to 1.53 x 10-5 K-1 in the temperature range 298-1273 K. Scanning electron microscopy indicates austenitic grains of sizes in the range 100-150μm and chromium carbide precipitate at grain boundaries after the HT-XRD heat treatment.

Effect of Improved ThO2 Particle Dispersion in Nickel on High-Temperature Strength

1970 ◽  
Vol 28 ◽  
pp. 444-445
Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer
Keyword(s):  
High Temperature ◽  
Metal Matrix ◽  
Oxide Particle ◽  
Oxide Phase ◽  
Dislocation Motion ◽  
Particle Dispersion ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Oxide Particles ◽  
The Stability

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.

scholarly journals Study on the Stability of the Electrical Connection of High-Temperature Pressure Sensor Based on the Piezoresistive Effect of P-Type SiC

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 216
Author(s):  
Yongwei Li ◽  
Ting Liang ◽  
Cheng Lei ◽  
Qiang Li ◽  
Zhiqiang Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Extreme Environment ◽  
Maximum Temperature ◽  
Piezoresistive Effect ◽  
Electrical Connection ◽  
Contact Stability ◽  
The Stability ◽  
P Type

In this study, a preparation method for the high-temperature pressure sensor based on the piezoresistive effect of p-type SiC is presented. The varistor with a positive trapezoidal shape was designed and etched innovatively to improve the contact stability between the metal and SiC varistor. Additionally, the excellent ohmic contact was formed by annealing at 950 °C between Ni/Al/Ni/Au and p-type SiC with a doping concentration of 1018cm−3. The aging sensor was tested for varistors in the air of 25 °C–600 °C. The resistance value of the varistors initially decreased and then increased with the increase of temperature and reached the minimum at ~450 °C. It could be calculated that the varistors at ~100 °C exhibited the maximum temperature coefficient of resistance (TCR) of ~−0.35%/°C. The above results indicated that the sensor had a stable electrical connection in the air environment of ≤600 °C. Finally, the encapsulated sensor was subjected to pressure/depressure tests at room temperature. The test results revealed that the sensor output sensitivity was approximately 1.09 mV/V/bar, which is better than other SiC pressure sensors. This study has a great significance for the test of mechanical parameters under the extreme environment of 600 °C.

Experimental Study of Typical Graded Asphalt Mixture about Dynamic Stability at High Temperature

2016 ◽  
Vol 858 ◽  
pp. 300-304
Author(s):  
Zhen Fu Chen ◽  
Dan Wu ◽  
Qiu Wang Tao ◽  
Yuan Chu Gan
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
High Temperature ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Specimen Thickness ◽  
High Temperature Stability ◽  
Change Trend ◽  
Comparison And Analysis ◽  
The Stability

The high temperature stability of AC-16, AC-13, AC-20 under specimen thickness of 5cm and 6cm is studied through indoor asphalt mixture high rutting test, Through comparison and analysis about experimental data, it is found that the stability of AC-16, AC-13, AC-20 asphalt mixture at high- temperature decreases in turn. It is shown that thickness changes did not affect the change trend of the high temperature stability under gradation change, and the stability of AC-16 at high-temperature is the best, the AC-13 is second and the AC-20 is less.

Highly Stable Ir-Ta-O Electrode for Ferroelectric Material Deposition

2000 ◽  
Vol 655 ◽  
Author(s):  
Fengyan Zhang ◽  
Sheng Teng Hsu ◽  
Jer-shen Maa ◽  
Yoshi Ono ◽  
Ying Hong ◽  
...  
Keyword(s):  
High Temperature ◽  
Bottom Electrode ◽  
Temperature Stability ◽  
Gate Oxide ◽  
Ferroelectric Material ◽  
High Temperature Stability ◽  
Material Deposition ◽  
Long Time ◽  
The Stability ◽  
Thin Gate Oxide

AbstractIr-Ta-O composite bottom electrode has extraordinary high temperature stability. It can maintain good conductivity and integrity even after 5min annealing at 1000 °C in oxygen ambient. The thermal stability of Ir-Ta-O on different substrates has been studied. It shows that Ir-Ta-O is also very stable on Si and SiO2 substrates. No hillock formation and peelings of the bottom electrode were observed after high temperature and long time annealing in O2 ambient. SEM, TEM, XRD, and AES have been used to characterize the Ir-Ta-O film and the interfaces between Ir-Ta-O bottom electrode and Si or SiO2 substrate. The composition and conductivity changes of the electrode during oxygen ambient annealing and the interdiffusion issue will be discussed. Furthermore, Ir-Ta-O/SiO2/Si capacitor with 30Å gate oxide was fabricated and the C-V and I-V characteristics were measured to confirm the stability of Ir-Ta-O on thin gate oxide.

Factors Affecting the Stability of Scale Inhibitors Used for Capillary Injection in High Temperature Wells

2013 ◽  
Author(s):  
J. Rick Griffin ◽  
James R Johnstone ◽  
Terry E Cotter ◽  
Ashleigh E O'Brien
Keyword(s):  
High Temperature ◽  
Factors Affecting ◽  
The Stability
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