Otimização do desempenho tribológico do Aço AISI 52100 por deposição a plasma com cilindros catódicos

Abstract

Amid growing concerns about diversifying energy production and reducing environmental impacts, the wind energy sector has emerged as a sustainable alternative. However, the reliability of wind turbines is still compromised by the high frequency of bearing failures. In this context, this study aimed to optimize the tribological performance of AISI 52100 steel, widely used in these components, through the deposition of thin films via plasma using cathodic cylinders composed of Ti + Al₂O₃. Two different treatments were carried out, varying the gas atmosphere composition (N₂/H₂) and deposition temperature, in order to investigate their effects on surface hardness, friction coefficient, and wear. The samples were characterized by Vickers microhardness tests, pin-on-disk tribological tests, X-ray diffraction (XRD), and profilometry. The results showed a significant increase in surface hardness for the treated samples, especially for Treatment 2 (in an atmosphere of 80% N₂ and 20% H₂ at 350°C), which reached 1204 HV compared to 545 HV for the untreated sample. The nitrogen-rich atmosphere favored the formation of nitrides on the material's surface. In the tribological test, the friction coefficient was reduced from 0.40 (untreated sample) to as low as 0.19 in the second treatment, demonstrating the effectiveness of the surface modification. XRD analysis confirmed the formation of titanium nitride (TiN) and iron nitride (Fe₄N) on the treated surface. It is concluded that plasma deposition using cathodic cylinders is a viable and effective technique to improve the wear resistance of alloy steels, with potential applications in critical components of the wind energy industry and other sectors requiring high durability and mechanical performance.