Development of Forming Process by Using Partial Heating for Titanium Alloys

Titanium alloy is expected to expand its use for future aircraft due to its good mechanical properties and compatibility with composite materials. The titanium alloys components are usually formed by using hot forming process. But, as the hot forming of titanium are conducts at around 700ºC and it needs expensive dies made of heat resistance alloy and a hot forming press. The cost of this process is expensive and the size of parts is depending on the hot forming press. Therefore, the forming process by using partial heating is developing in order to decrease the forming cost of titanium alloy components.

The titanium sheets normally can not be stretch formed at room temperature as its high yield stress. At this process, the titanium sheet is stretched by stretcher at room temperature, and partially heated by a scanning lamp. As yield stress of heated area is decreased and sheet is plastically formed. After scanning by the lamp, sheet is formed close to the die shape. This process has advantages compared to the hot forming. This process doesn’t need dies made of heat resistance alloy, as most part of dies is not heated up to high temperature. In this process, a stretcher for aluminum parts can be formed only by a lamp with scanner.

In this presentation, this forming process and the evaluation results of formed parts are presented. The numerical simulation results of this process are also presented to clarify this process.

This work was conducted as a part of the project, "Aerospace Industry Innovation Program-Advanced Materials & Process Development for Next-Generation Aircraft Structures" founded by Ministry of Economy, Trade and Industry (METI) of Japan.