A comprehensive experimental investigation on the influences of the process variables on warm incremental forming of Ti-6Al-4V titanium alloy using a simple technique

The incremental forming has recently acquired a significant importance in various applications, such as automotive, aerospace, and medical industries. The present investigation is concerned with the warm incremental forming of Ti-6Al-4V titanium alloy. With this regard, the groove test was employed as a simple technique to study the effects of different variables, namely, the process temperature, the vertical pitch, and the tool diameter, on the forming limit diagram of the material, the springback, drawing depth, final temperature of the sheet, and the thickness variation of the product. The sheet temperature was the most important parameter affected by the interfacial friction and the other process variables. The experimental findings illustrated that the greater the vertical pitch and/or the tool diameter, the larger the formability and drawing depth of the sheet sample before its fracture. Moreover, decreasing the tool diameter and increasing the vertical pitch and the initial process temperature resulted in more thickness reduction. The actual process temperature simultaneously affected the elastic modulus and the flow stress of the component. However, the flow stress reduction due to the temperature rise overcame the elastic modulus decrease and, finally, the springback was lower at higher process temperatures.