strain distribution for cp-ti in cyclic extrusion compression angular pressing by rsm

Cyclic extrusion compression angular pressing (cecap) is a novel severe plastic deformation (spd) method applied to improve the mechanical and metallurgical properties of materials. in this research, finite element analysis and response surface method were considered for cp-ti in cecap process. temperature, input extrusion diameter, exit extrusion angle, shear factor and longitudinal distance of input extrusion to the ecap region were selected as input parameters to study strain distribution in the current process. the analysis of variance (anova) was developed for current work, and the results showed that input parameters of input extrusion diameter and shear factor, and the interaction of the temperature and longitudinal distance of input extrusion to ecap region, and the shear factor and longitudinal distance of input extrusion to ecap region considerably affect the strain distribution. hardness measurement in section a at the points near the center and outer surfaces of the sample showed the hardness of 21 and 24 hrc respectively. at this point, the maximum difference for hardness was achieved at about 12% throughout the cross section which is in suitable agreement with the strain distribution model. moreover, the optical microscope (om), both current cdecap and conventional cecap, showed that the majority of deformed grains were enlarged. the average deformed grain size for the current cecap was reduced to 100 nm, which is considerably smaller than the conventional cecap with an average grain size of 300 nm. furthermore, the load-stroke diagram was achieved by executing experimental tests and comparing the results achieved the numerical model. the results showed a good agreement between them.