scholarly journals The effect of surface preparation on high temperature oxidation of Ni, Cu and Ni-Cu alloy

2019 ◽  
Vol 476 ◽  
pp. 442-451 ◽  
Author(s):  
Daria Serafin ◽  
Wojciech J. Nowak ◽  
Bartek Wierzba
2020 ◽  
Vol 4 (1) ◽  
pp. 15 ◽  
Author(s):  
Wojciech J. Nowak ◽  
Małgorzata Tomków ◽  
Patrycja Wierzba ◽  
Kamil Gancarczyk ◽  
Bartek Wierzba

The Ni-base superalloys facing high temperature require further protection against high temperature oxidation. One of the most common methods providing high temperature oxidation resistance is the production of aluminide layers (NiAl-coatings). It is known that the thickness of produced diffusion layer can be controlled by the temperature and time of aluminization process. However, no research on the effect of surface roughness on aluminization kinetics was conducted so far. Then, to elucidate the effect of surface roughness on aluminization kinetics, diffusion layers were obtained by an in-pack aluminization method on the IN 617 alloy with differently prepared surfaces, namely polished, ground using 220 grit SiC paper and 80 grit SiC paper. The obtained results revealed that different surface preparation does not affect the chemical and phase composition of produced layers. However, a strong influence of surface preparation method on aluminide layers thicknesses was observed. Namely, it was found that the increase in substrate surface roughness results in an increase of aluminization kinetics. The dependence between surface roughness and thickness of aluminide layers was found to be logarithmic. Moreover, it was found that the aluminization kinetics is influenced, especially at early stages of the aluminization process.


2021 ◽  
pp. 163007
Author(s):  
Zi J. Zhao ◽  
Wan P. Li ◽  
Yen H. Chen ◽  
Xin Y. Liu ◽  
Zi X. Zhou ◽  
...  

2019 ◽  
Vol 944 ◽  
pp. 110-119 ◽  
Author(s):  
Hang Chen ◽  
Guang Bao Mi ◽  
Pei Jie Li ◽  
Chun Xiao Cao

The oxidation behavior and mechanism of Ti-Cu alloys (0≤w(Cu)≤20%) in the temperature range of 1000°C~1300°C are studied by thermogravimetric analysis(TGA) combined with SEM, EDS and XRD analysis methods. The results show that the oxidation rates of Ti-Cu alloys increase sharply when the temperature rises above 1000°C. The oxidation products have a three-layer structure, from the outside to the inside, which are dense outer oxide layer of TiO2, porous inner oxide layer of low valence oxide of Ti and Cu-enriched layer. With the increase of the temperature, the thicknesses of oxide layers of Ti-Cu alloy increase and the Cu-enriched phase increases gradually and melts. The melting Cu-enriched phase flows to the oxidation surface along the grain boundaries of the oxide layer. The high temperature oxidation resistance of Ti-Cu alloys declines with the increase of Cu content. The main reason is that more liquid Cu-enriched phase is formed and flows to the oxidation surface along the oxide grain boundaries in the Ti-Cu alloy, and Ti and O ions can diffuse more easily along the liquid Cu-enriched phase, which increases the oxidation rates.


2019 ◽  
Vol 92 (5-6) ◽  
pp. 525-540 ◽  
Author(s):  
Richard P. Oleksak ◽  
Gordon R. Holcomb ◽  
Casey S. Carney ◽  
Lucas Teeter ◽  
Ömer N. Doğan

CORROSION ◽  
1959 ◽  
Vol 15 (3) ◽  
pp. 57-62 ◽  
Author(s):  
D. CAPLAN ◽  
M. COHEN

Abstract The scaling of austenitic stainless steels Type 302, 309 and 330 has been investigated by weight gain vs time measurements in air at 1600 to 2000 F and subsequent examination of the scales. As had been found previously with chromium steel, the curves exhibit breaks indicating intermediate periods of rapid oxidation due to disruption of the protective scale layer. Accumulation of silica at the metal/scale interface is found to contribute to this disruption; voids are considered to have the same effect. A distinction is drawn between such breaks and the type which arises from the extraordinary protectiveness of an initial thin oxide film, which is markedly affected by surface preparation and prior treatment. 3.2.3


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