Micro‐Forming Using Ultrafine‐Grained Aluminum Processed by Equal‐Channel Angular Pressing

A very high‐purity (99.999%) aluminum was processed by equal‐channel angular pressing (ECAP) at room temperature through 1 to 8 passes using a die with a channel angle of 90°. Analysis shows that processing by ECAP produces an ultrafine‐grained (UFG) structure with a grain size of ≈1.3 μm and with microhardness and microstructural homogeneity. The mechanical properties and the fracture behavior were evaluated using micro‐tensile testing after ECAP processing. A micro‐forming process was used to fabricate a micro‐turbine at ambient temperature and subsequent examination demonstrated that UFG pure aluminum gives higher strength and more uniform mechanical properties by comparison with conventional coarse‐grained pure aluminum. The results confirm the very significant potential for using UFG pure aluminum for micro‐forming at ambient temperature.