Production of the Ultrafine-Grained Materials by Sandglass Extrusion Process
A new method of getting ultrafine grain has been investigated,which is called“Sandglass Extrusion”(SE).The ultrafine grain can be obtained in the billet material due to the large plastic strain and the dynamic recrystallization during SE.The microstructures,microhardness and superplasticity of test material after SE have been studied.The experimental results show that the equal axial ultrafine microstructures can be introduced to the bulk test material during sandglass extrusion.The high strain rate superplasticity can be realized.