2011 Volume 52 Issue 604 Pages 579-583
A forming experiment has been carried out to develop a new incremental forming method for the high-strength titanium alloy sheet Ti-6Al-4V, using a bar tool with a spherical head. As a pre-experiment, a blank sheet was heated locally using a high-frequency induction coil located beneath the sheet. The temperature of the sheet was adjusted and kept constant by controlling induction current depending on the feedback from infrared thermometer reading. With this system, the energy of heating depends on the distance between the sheet and the induction coil. This property enables the separation of the heated and non heated areas on the sheet throughout the forming process. The heated area has better condition to deform by material softening. The non heated area is expected to not crack as a result of the recovered strength of lower temperature, even though the area has been thinned by the deformation. Finally, a truncated pyramid, with a 40% reduction in the thickness of the side wall, was formed successfully, under some suitable forming conditions. It was found that this heating method was effective for forming titanium alloy sheets, and that the pattern of thickness variation was the same as that in a conventional forming process.
