Effect of Microstructural Variation on Dry Sliding Wear Behavior of Ti-6Al-4V Alloy

• Published in: Journal of materials engineering and performance 2014-06, Vol.23 (6), p.2092-2102
• Main Authors: Sahoo, R., Jha, B. B., Sahoo, T. K., Sahoo, D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Characterization and Evaluation of Materials; Chemistry and Materials Science; Contact of materials. Friction. Wear; Corrosion and Coatings; Engineering Design; Exact sciences and technology; Materials Science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Quality Control; Reliability; Safety and Risk; Tribology
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-014-0987-7

The present article evaluates the influence of independent control factors such as microstructural variation, normal load, sliding velocity, and test duration on dry sliding wear behavior of Ti-6Al-4V alloy at room temperature using a statistical approach. Ti-6Al-4V alloy has been heat treated in a controlled manner in order to produce different microstructural features (i.e., lamellar, bimodal, and equiaxed). Lamellar microstructure is found to be harder than bimodal microstructure followed by equiaxed microstructure in Ti-6Al-4V alloy. Dry sliding wear tests have been carried out using a multiple Tribo tester following a well planned experimental schedule based on Taguchi’s L 9 orthogonal array design. Dry sliding wear behavior of Ti-6Al-4V alloy consisting of various microstructural features is related to their hardness values. Results indicated that lamellar microstructure has the lowest sliding wear resistance followed by bimodal and equiaxed microstructure. With the help of signal-to-noise ratios, optimal combination of control factors to minimize the dry sliding wear in Ti-6Al-4V alloy has been determined. Normal load is the most significant control factor influencing the dry sliding wear behavior of investigated Ti-6Al-4V alloy followed by sliding velocity, test duration, and microstructural variation. Normal load has greater static influence of 27.02%, sliding velocity has an influence of 18.07%, test duration has an influence of 12.71%, and microstructural variation has an influence of 10.55% on weight loss of Ti-6Al-4V alloy due to wear having R 2  = 0.89. Two wear mechanisms have been identified: oxidative wear occurs at the lowest sliding velocity and delamination wear occurs at the highest sliding velocity. Optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and Rockwell hardness measurements have been used to characterize the microstructures in order to correlate the results obtained.