Effect of Accumulated Strain on the Microstructure and Properties of TC4 Alloy Prepared by Continuous Various Cross-section Recycled Extrusion

摘要

The TC4 titanium alloy were deformed at 800°C, 2mm/s with various extrusion loops by a new sever plastic deformation method-Continuous Various Cross-section Recycled Extrusion, then the microstructure and microhardness of the specimen along the radial, the maximum deformation force in each extrusion procedure were also investigated. The results show that Continuous Variable Cross-section Recycled Extrusion is a better method for obtaining TC4 alloy with fine and equiaxed microstructure. With the increase of extrusion loops from 3 to 6, the grain size decreases and its size are about 2 to 3 μm. As the extrusion loops increases from 6 to 8, the grain size is similar to that of the 6 loops. However, the grain size increases slightly due to multiple heating as the extrusion loops increases from 8 to 12. Moreover, the microhardness and maximum deformation force of the specimen in each extrusion procedure are higher while the extrusion loops is from 6 to 8. Therefore, the extrusion loop of 6 is the optimal, the microstructure is fine and equiaxed and it also distributes homogeneously.