Innovative Superplastic Forming Based on In-Situ Infra-Red Sheet Heating

This paper describes the research work that was performed in order to propose an innovative and low cost process route for superplastic forming of aluminum and titanium alloy sheets. The driving idea was to heat only the metallic sheet using heating elements included in the pressure chamber. Several heating configurations have been tested and equipment designs investigated. Based on experimental results and numerical thermal analysis, it was found that halogen heating lamps with a high reflective thermal insulation was the best for the upper pressure chamber, whereas low effusivity Refractory Castables materials seems optimal as low cost forming die. Energy consumption evaluation shows more than 80% energy saving in nominal titanium alloy forming. A pilot forming equipment was developed and first aluminum sheet forming trials give interesting results.