Superplastic Forming Analysis for Tool Design and Process Development

The superplastic forming process is used to fabricate parts with complex geometry for both commercial and military aircraft. Elimination of fasteners and reduction of part count, assembly time and weight can be realized with the superplastic forming process, but tool design and forming process development costs and schedule must be minimized. Boeing has developed and used computer analysis and simulation software to help design tooling and develop the forming process. Within the Integrated Product Team (IPT) environment at Boeing, analysis is leveraged with tool design and manufacturing experience to reduce the tooling design and process development time. The capability to predict final part thickness within 5% allows tooling designs to be developed and weight and performance to be predicted early in the design cycle. Examples show the predicted improvement in part thickness uniformity caused by tool design, preforming and forming process control. These tooling concepts and forming processes were used to fabricate production parts. A comparison between predicted and measured thickness was excellent for both distribution of thickness and absolute thickness.