The application of the Equal Channel Angular Pressing (ECAP) process imposes severe plastic strains on the metallic billet. As a result of these imposed strains, the initially coarse grains are transformed into ultra-fined or nanostructured grains, and beneficial microstructural evolutions occur in the texture of the material, which lead to improvements in mechanical properties. In this study, commercially pure titanium (CP-Ti) BT1-0, as a hard-to-deform material, was placed inside a casing made of pure copper and subjected to four passes of warm ECAP at a temperature of 250°C in a 135° channel using route Bc, accompanied by the application of back pressure through extrusion in the end of die. The simultaneous effect of back pressure and the casing on the grain structure and mechanical properties of the target material, i.e., CP-Ti, was evaluated. Experimental results showed that the grain size was refined from 49 µm in the initial annealed state to 710 nm after four ECAP passes. The compressive yield and ultimate strength, and also compressive elongation changed from 267 MPa, 899 MPa, and 51.8 mm/mm in the non-ECAPed condition to 958 MPa, 1375 MPa, and 30.7 mm/mm after ECAP processes, corresponding to increases of 359% and 153%, and a decrease of 59%, respectively. The average Vickers hardness also increased from 163 Hv in the initial annealed state to 289 Hv after four ECAP passes, representing a 77% enhancement.
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Naseri,R . (2026). Evaluation of mechanical properties of ultrafine-grained pure titanium produced via warm ECAP process by concurrently utilizing casing and back pressure. Science and Technology in Mechanical Engineering, 4(2), 47-63. doi: 10.22034/stme.2025.530050.1136
MLA
Naseri,R . "Evaluation of mechanical properties of ultrafine-grained pure titanium produced via warm ECAP process by concurrently utilizing casing and back pressure", Science and Technology in Mechanical Engineering, 4, 2, 2026, 47-63. doi: 10.22034/stme.2025.530050.1136
HARVARD
Naseri R. (2026). 'Evaluation of mechanical properties of ultrafine-grained pure titanium produced via warm ECAP process by concurrently utilizing casing and back pressure', Science and Technology in Mechanical Engineering, 4(2), pp. 47-63. doi: 10.22034/stme.2025.530050.1136
CHICAGO
R Naseri, "Evaluation of mechanical properties of ultrafine-grained pure titanium produced via warm ECAP process by concurrently utilizing casing and back pressure," Science and Technology in Mechanical Engineering, 4 2 (2026): 47-63, doi: 10.22034/stme.2025.530050.1136
VANCOUVER
Naseri R. Evaluation of mechanical properties of ultrafine-grained pure titanium produced via warm ECAP process by concurrently utilizing casing and back pressure. STME. 2026;4(2):47-63 (In Persian). doi: 10.22034/stme.2025.530050.1136
Science and Technology in Mechanical Engineering