A Comparative Study on Characterization and High-Temperature Wear Behaviors of Thermochemical Coatings Applied to Cobalt-Based Haynes 25 Superalloys

Abstract

This study investigated the characteristic properties of aluminizing, boronizing, and boro-aluminizing coatings grown on Haynes 25 superalloys and their effects on the high-temperature wear behavior. The coating processes were conducted in a controlled atmosphere at 950 °C for 3 h. Characterization studies were performed using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis, nanoindentation testing, and high-temperature wear tests. It was determined that the thickness values of aluminide, boride, and boride–aluminide coatings were 140 ± 1.50 µm, 37.58 ± 2.85 µm, and 14.73 ± 1.71 µm, and their hardness values were 12.23 ± 0.9 GPa, 26.34 ± 2.33 GPa, and 23.46 ± 1.29 GPa, respectively. The hardness of the coatings resulted in reduced wear volume losses both at room temperature and at 500 °C. While the best wear resistance was obtained in the boronized sample at room temperature due to its high hardness, the best wear resistance at 500 °C was obtained in the boro-aluminized sample with the oxidation–reduction effect of Al content and the lubricating effect of B content in the boro-aluminide coating. This indicates that the presence of aluminum in boride layers improves the high-temperature wear resistance of boride coatings. The coated samples underwent abrasive wear at room temperature, whereas at 500 °C, the wear mechanism shifted to an oxidative-assisted adhesive wear mechanism.

Development of a wear coefficient equation for the A A7075-B4C composite – steel interface

“…These MML prevents direct contact between the two sliding body leads to the reduction of wear rate, confirmed through EDS analysis as shown in figure 6. Beyond the critical reinforcing percentage (7.5%), the wear rate increases attribute to the following factors (i) owing to agglomeration of particles delamination wear occurred [21] (ii) due to the reduction of hardness because of higher void percentage [22]. Differentiating V with respect to the V , r The equation (4) is given by…”

The Tribological Properties of Low-Sulfur and Low-Phosphorus Halogen-Free Ionic Liquids as Lubricants for the Nickel-Based Alloy Inconel 690

“…Under the action of friction heat, physical adsorption and friction chemical reactions occur [20]. A lubricating film is generated on the friction surface to prevent direct contact between cemented carbide and nickel-based alloys [15,31,32]. The lubricating film plays a role in reducing friction, promoting anti-wear.…”

Electron Beam Processing of Diffusion Boroaluminizing Layerson the Surface of Steel 5khnm

“…В машиностроении также используют многокомпонентную ХТО, которая заключается в одновременном или последовательном насыщении поверхности несколькими химическими элементами [8]. Бороалитирование -один из комплексных методов ХТО, который существенно увеличивает сопротивление износу и повышает жаростойкость, коррозионную стойкость и улучшает другие свойства поверхностных слоев деталей машин [9]. В современных исследованиях продемонстрированы результаты применения электронных пучков совместно с другими технологиями, такими как электродуговая и электроконтактная проволочная наплавка [10], модификация поверхностных слоев аддитивно изготовленных изделий [11], поверхностное легирование [12], комбинация применения плазменных потоков с последующим низкоэнергетическим сильноточным электронным пучковым воздействием [13].…”