Comprehensive analysis of surface integrity modification of ball-end milled Ti-6Al-4V surfaces through vibration-assisted ball burnishing

• Published in: Journal of materials processing technology Vol. 267; pp. 230 - 240
• Main Authors: Jerez-Mesa, R., Travieso-Rodríguez, J.A., Landon, Y., Dessein, G., Lluma-Fuentes, J., Wagner, V.
• Format: Journal Article Publication
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2019; Elsevier BV; Elsevier
• Subjects: Ball burnishing; Burnishing; End milling; Engineering Sciences; Enginyeria mecànica; Hardness; Integrity; Materials; Mechanical engineering; Mechanics; Process parameters; Residual stress; Superfícies; Surface integrity; Surface layers; Surface texture; Surfaces; Textura; Texture; Titani; Titanium; Titanium base alloys; Ultrasonic vibration; Vibration; Vibration analysis; Vibration-assisted ball burnishing; Workpieces; Àrees temàtiques de la UPC; St; np; Std; VABB; ae; d; Surface integrity; Fp; NVABB; Ssk; Hardness; S0i; vC; HV; ap; p; vf; Vibration-assisted ball burnishing; Titanium; Surface texture; Sku; Sq; Residual stress
• ISSN: 0924-0136; 1873-4774
• DOI: 10.1016/j.jmatprotec.2018.12.022

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This paper is an experimental research about the mechanical effects on Ti-6Al-4V surfaces treated with an ultrasonic vibration-assisted ball burnishing process. Its aim is to define the process parameters to achieve the best surface integrity on the target workpiece, as well as identifying the effects caused by the introduction of vibrations as a means of assistance. A Taguchi orthogonal array including five factors (preload, number of passes, feed velocity, strategy and original surface texture) was applied to perform the process on ball-end milled surfaces. A comprehensive analysis of the effects was performed, by considering in depth three different facets of surface integrity, namely, topology, residual stress and hardness. Hence the extensive result datasets presented in this paper, which deliver an exhaustive description of the process effects by combining a triple approach in the results analysis section. The effect of vibrations is proved positive to enhance the texture as long as the original surface is not characterized by Sq >2 μm. Furthermore, only the preload and number of passes influence the results. In terms of residual stress, all parameters are influential in the results, especially the burnishing strategy, through which a specific direction can be reinforced. Finally, the burnishing operation proves to modify the hardness of deep layers down to 0.5 mm, applying the vibration-assisted process. The main conclusion derived from these works is a technical recommendation to treat the Ti-6Al-4 V surface through the process, aiming to find a balanced comprehensive surface integrity enhancement.