Surface Integrity of Ball Burnished 316L Stainless Steel

316L is a type of austenitic stainless steel that offers a good combination of mechanical properties, corrosion resistance, and biocompatibility. In some industrial applications, it is necessary to proceed to finish treatments to extend the lifetime of the mechanical parts. In the present chapter, ball burnishing treatment is applied to improve the surface integrity of 316L since the performance behavior of parts is directly dependant on the surface properties of the used material. Both surface topography and surface microhardness of 316L after subjection to ball burnishing are studied. The number of burnishing passes is varied by up to five to investigate its effect on the results. Optical profilometer and atomic force microscopy (AFM) were used to analyze the surface roughness and surface topography texture while measurements of microhardness Vickers were proceeded to investigate the changes in surface hardening.

Influence of Some Microchanges Generated by Different Processing Methods on Selected Tribological Characteristics

Different processing methods can change the physical–mechanical properties and the microgeometry of the surfaces made by such processes. In turn, such microchanges may affect the tribological characteristics of the surface layer. The purpose of this research was to study the tribological behavior of a test piece surfaces analyzing the changes on the values of the coefficient of friction and loss of mass that appear in time. The surfaces subjected to experimental research were previously obtained by turning, grinding, ball burnishing, and vibroburnishing. The experimental research was performed using a device adaptable to a universal lathe. Mathematical processing of the experimental results led to the establishment of power-type function empirical models that highlight the intensity of the influence exerted by the pressure and duration of the test on the values of the output parameters. It was found that the best results were obtained in the case of applying ball vibroburnishing as the final process.

The Effect of Ball Burnishing on Dry Fretting

Experiments were conducted under a dry gross fretting regime. Steel discs were put in contact with ceramic balls. Before tribological tests, discs were subjected to ball burnishing with different pressures. Due to ball burnishing, a decrease in surface amplitude and an increase in microhardness occurred. Ball burnishing caused decreases in the friction force and volumetric wear of up to 45% in comparison to sliding pairs containing milled discs. The friction force and volumetric wear were higher for a higher roughness of disc.

Ultrasonic Vibration-Assisted Ball Burnishing Tool for a Lathe Characterized by Acoustic Emission and Vibratory Measurements

This paper focuses on a resonant system used to induce a low-amplitude movement and ultrasonic frequency to complement a ball burnishing process on a lathe. The system was characterized through the combination of different techniques. A full vibratory characterization of this process was undertaken with the purpose of demonstrating that the mechanical system—composed of the tool and the machine—does not present resonance phenomena during the execution of the operation that could lead to eventual failure. This dynamic analysis validates the adequateness of the tool when attached to an NC lathe, which is important to guarantee its future implementation in actual manufacturing contexts. A further aim was to confirm that the system succeeds in transmitting an oscillating signal throughout the material lattice. To this end, different static and dynamic techniques that measure different vibration ranges—including impact tests, acoustic emission measurement, and vibration measurement—were combined. An operational deflection shape model was also constructed. Results demonstrate that the only high frequency appearing in the process originated in the tool. The process was not affected by the presence of vibration assistance, nor by the burnishing preload or feed levels. Furthermore, the frequency of the assisting ultrasonic vibration was characterized and no signal due to possible damage in the material of the specimens was detected. These results demonstrate the suitability of the new tool in the vibration-assisted ball burnishing process.

Comparative study: Impact of Ball burnishing and shot peening Process on Aluminium 2024 alloy

Compressive residual stress is the major aspect in the extension of the fatigue life of aeroengine components. In this study, a modified burnishing surface treatment and conventional shot peening process was used was proposed to improve surface integrity characteristics such as surface finish, hardness, and stable, advantageous compressive residual stress in turned Cylindrical Aluminum 2024Specimen. In burnishing process, a rolling rigid spherical HSS ball is pressed across an Aluminum 2024Specimen under definite fluid pressure generated by the hydraulic unit and also shot peening was carried out at a shot velocity of 300 m/s. This research examined the effect of burnishing treatment and shot peening process on beneficial compressive residual stresses.