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

Abstract

The present article describes the effect of microstructural variations—that is, lamellar, bimodal, and equiaxed—on solid particle erosion wear behavior of Ti-6AL-4V alloy at room temperature. Erosion tests were carried out at various test conditions using an air jet–type test rig and Taguchi's orthogonal array experimental design. The results indicated that impact velocity is the most significant controlling factor influencing the solid particle erosion wear of Ti-6Al-4V alloy followed by impact angle, microstructural variation, and size of erodent. The lamellar microstructure of Ti-6Al-4V alloy has excellent erosion resistance, followed by bimodal and equiaxed microstructures. Ploughing or pile-up leading to platelet formation was found to be the primary mechanism of material loss in erosion of Ti-6Al-4V alloy. This mechanism of material loss is independent of its microstructural variation. These results were determined after observation of the eroded surface under a scanning electron microscope. Optical microscopy, Rockwell hardness testing, and scanning electron microscopy were used to characterize the microstructures and eroded surfaces of the Ti-6Al-4V alloy in order to correlate the results obtained.

KEY WORDS:

• Taguchi's Experimental Design
• Ti-6Al-4V Alloy
• Erosion
• Microstructure
• Hardness

ACKNOWLEDGEMENT

The authors are grateful to Professor B. K. Mishra, Director, Institute of Minerals and Materials Technology, Bhubaneswar, for his valuable suggestions and guidance during the course of this investigation. Assistance received from our other colleagues in the Surface Engineering Department is also gratefully acknowledged.