Effect of boriding on high temperature tribological behavior of CoCrMo alloy

Öge, Mecit; Küçük, Yılmaz; Öge, Tuba Özdemir; GÜNEN, Ali; Kanca, Yusuf; Gök, Mustafa Sabri

doi:10.1016/j.triboint.2023.108697

Cited by 19 publications

(4 citation statements)

References 47 publications

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“…The occurrence of the Kirkendall effect in the diffusion region varies among these studies. It is reported to occur in some studies [19,25], while it is not observed in others [20,21], including this study. These discrepancies can be attributed to differences in boronizing powder content, temperature, and the duration of boriding in the coating process.…”

Section: Xrd and Microstructure Analysescontrasting

confidence: 57%

“…While there is a significant decrease in hardness between the coating and diffusion zone, the relatively small decrease in hardness within the matrix region indicates that the matrix remains unaffected by heat treatments and maintains its original structure. The highest hardness values are found in the boride layer due to the presence of harder phases like Cr-B and W-B in the Co-B and Co 2 B phases [19][20][21]. Additionally, numerous studies have reported that phases containing aluminum exhibit lower hardness values compared to boride phases [18,24,26].…”

Section: Xrd and Microstructure Analysesmentioning

confidence: 99%

“…Several studies have reported improvements in these alloys' wear and oxidation resistance, ranging from room temperature up to 750 • C, thanks to these coatings [17,18]. However, upon reviewing the literature, it can be observed that while these thermomechanical coatings on cobalt-based superalloys have been investigated for their wear resistance in various biological fluids at room temperature [11,19,20], their high-temperature wear behavior has been rarely studied [21].…”

Section: Introductionmentioning

confidence: 99%

“…However, cobalt-based superalloys have many applications in high-temperature abrasive environments such as gas turbines, nuclear power plants, high-temperature furnaces, and the oil and gas industry [1,2,22]. When thermomechanical coatings are applied to the surfaces of these superalloys, they improve surface hardness and chemical inertness and provide a thermal barrier effect, resulting in enhanced oxidation, corrosion, and wear resistance at high temperatures [10][11][12][13][14][17][18][19][20][21]. These advantages enhance the performance of cobalt-based superalloys, enabling their use in more challenging operating conditions.…”

Section: Introductionmentioning

confidence: 99%

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

Günen

Ergin

2023

Coatings

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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.

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