Stretch Forming of Ti-6Al-4V Hybrid Parts at Elevated Temperatures

Abstract

Hybrid components produced by two or more different process technologies grant the possibility to compensate the drawbacks of the used processes. The combination of additive manufacturing (AM) and forming offers geometrical freedom in extensions of geometrical simple parts in a cost-efficient way. Unlike the combination of bulk metal forming and AM, sheet metal forming and AM is less investigated. Especially for Ti-6Al-4V, which is widely used in AM but has a low formability at room temperature, research is still needed. In this study, the formability of hybrid parts made of Ti‑6Al‑V consisting of sheet material and additively manufactured elements (AME) is investigated for a hemispherical punch geometry. Thus, a designed tool for forming of hybrid parts at elevated temperatures is used. First investigations with a specially designed stretch forming tool demonstrate the distinct influence of the additively manufactured bodies on the stretch forming process of hybrid parts made of Ti‑6Al‑4V. Namely, the achievable drawing depth is reduced for hybrid parts as the functional elements are placed in the area of highest stresses, distorting material flow.