Strength and pore morphology of porous aluminum and porous copper with directional pores deformed by equal channel angular extrusion

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 528; no. 6; pp. 2363 - 2369
• Main Authors: Kim, T.B., Tane, M., Suzuki, S., Utsunomiya, H., Ide, T., Nakajima, H.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.03.2011; Elsevier
• Subjects: Aluminum; ALUMINUM ALLOYS (50 TO 99 AL); Aluminum base alloys; Condensed matter: structure, mechanical and thermal properties; Copper; Cross-disciplinary physics: materials science; rheology; DEFORMATION; Deformation and plasticity (including yield, ductility, and superplasticity); Equal channel angular extrusion; Exact sciences and technology; EXTRUSION; EXTRUSIONS; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; MORPHOLOGY; Orientation; Other heat and thermomechanical treatments; Physics; POROSITY; Porous metals; Treatment of materials and its effects on microstructure and properties; YIELD STRENGTH; Porous metals; Yield strength; Equal channel angular extrusion; Copper; Aluminum; Densification; Mechanical strength; Porous materials; Continuous casting; Aluminium; ECAP; Transition elements; Extrusion; Porosity; Microstructure
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.12.051

▶ Porous aluminum and porous copper with cylindrical pores oriented in one direction were deformed by equal channel angular extrusion using 150° die. ▶ Pores of porous aluminum with low porosity were collapsed by extrusions that were both parallel and perpendicular to orientation direction of pores. ▶ Yield strength of porous copper with high porosity drastically increased by extrusions that were parallel to orientation direction of pores, even though there was small decrease in porosity. ▶ Almost all pores of porous copper collapsed by extrusions that were perpendicular to orientation direction of pores. Porous aluminum with a porosity of 17.6% and porous copper with a porosity of 39.7% (the pores of both aluminum and copper were cylindrical and oriented in one direction) were deformed by equal channel angular extrusion using a 150° die with sequential 180° rotations (route C), and the mechanical strength and pore morphology after the extrusions were investigated. In the case of porous aluminum with low porosity, the pores were collapsed by the extrusions that were both parallel and perpendicular to the orientation direction of the pores. In contrast, the porosity of porous copper decreased slightly after extrusions that were parallel to the orientation direction of the pores, and the pores thus remained even after four extrusions. The yield strength after the second extrusion was 7.3 times greater than it was before the extrusion, even though there was a decrease in porosity of only 8%. On the other hand, almost all the pores of the porous copper collapsed after the fourth extrusion, when the extrusion direction was perpendicular to the orientation direction of the pores. Thus, the yield stress cannot be enhanced without being accompanied by progressive densification.