Materials Processing and Engineering for Superplastic Ceramics

该研究将研究超塑性变形氮化硅基和莫来石陶瓷材料的加工和性能，以建立描述多晶陶瓷蠕变应变变形行为的本构关系，并开发简单部件的超塑性成形工艺。包括陶瓷片材的气吹成形和超塑性陶瓷的扩散连接。超塑性成形是指零件在高温和不发生断裂的条件下缓慢变形成所需形状的过程。虽然超塑性成形在金属材料，特别是钛合金上的应用取得了一些成功，但将该工艺应用于陶瓷的成形是非常新颖的。陶瓷材料极难成型和精加工，通常需要磨削操作，这可能会损坏表面并导致故障。因此，将固体陶瓷变形成成形部件的能力将是一项重大进步。

The research will investigate the processing and properties of superplastically deformed silicon nitride-based and mullite ceramic materials to develop constitutive relationships describing the creep strain-deformation behavior of polycrystalline ceramics and to develop processes for the superplastic forming of simple components, including the gas blow-forming of ceramic sheets and the diffusion bonding of superplastic ceramics. Superplastic forming involves the slow deformation of the component into the desired shape at high temperatures and under conditions under which fracture does not occur. While superplastic forming has been applied with some success to metallic materials, titanium alloys in particular, the application of the process to the forming of ceramics is highly novel. Ceramic materials are extremely difficult to form and finish, normally requiring grinding operations which may damage the surface and cause failure. Therefore, the ability to deform solid ceramics into shaped parts would be a major advance.