Superplastic forming is an advanced manufacturing process, typically restricted to low volume and high value products. Refractory ceramics are a low cost option to substitute the high temperature resistant steels and other alloys conventionally used in superplastic forming dies, but their brittle nature is a limiting factor for most superplastic forming applications. Suitable surface coatings have shown a significant effect on wear resistance and can be employed to improve the ceramic performance in terms of tool life. This paper focuses on an initial study on protective coatings for superplastic forming ceramic dies to evaluate their effectiveness under superplastic forming conditions. Tests are conducted using a dedicated test rig built where the die‐blank interaction under superplastic forming conditions is replicated at laboratory scale. Two coating materials are tested and surface wear is compared with the uncoated surface of a particle‐reinforced fused silica refractory superplastic forming ceramic die. Results show that the selected coating materials have poor protective performance in comparison with the uncoated ceramic die, but they demonstrate the ability to assess protective coatings performance under superplastic forming conditions at a laboratory scale.

Superplastic forming (SPF) is an advanced sheet manufacturing process typically used for low- volume, high-value products. SPF dies made from refractory castables have a lower production cost than metal dies, but their brittle nature is a limiting factor. This work investigates surface degradation mechanisms in ceramic dies and how they are affected by the application of thermal spray coatings. Among the more notable accomplishments of the study is the development of a test rig that simulates die-part interface conditions during superplastic forming and monitors die wear, making it possible to predict ceramic die lifetime for different coatings.