Modular Heated Die System for Superplastic Forming
Publication Date: 2005-Sep-28
The IP.com Prior Art Database
Die System for Superplastic Forming
Superplastic forming (SPF) is a manufacturing process that takes advantage of some material's ability to be strained well past their rupture point under certain elevated temperature conditions. SPF of many parts is accomplished by blow-forming where a heated sheet is clamped in a die and gas pressure is applied to one side. The typical SPF process relies on heated platens in the press. In this arrangement, the SPF tool is attached to the platens and is heated through conduction. While this system has been shown to work for low volume manufacturing it has several drawbacks. First, it can take several hours to heat a die to the appropriate forming temperature which can significantly delay the start of production. Second, dies need to be cooled prior to die change which can cause additional down-time. Lastly, controlling temperature throughout a forming run can be difficult due to the heat loss when the die is opened for blank loading and part removal. A critical aspect of maintaining temperature during the opening of the die is the response time of the thermal system. That is, the heaters must respond to this heat loss so that the forming surface of the die maintains temperature. The relatively long distance between the heat source and the forming surface in conventional SPF dies makes for a sluggish response in terms of controlling temperature. This results in difficulty maintaining the target temperature over time.
One method of avoiding these drawbacks is to use a heated tool instead of a heated press. By lo...