title: Effect of bimodal harmonic structure design on the deformation behaviour and mechanical properties of Co-Cr-Mo alloy.
abstract: In the present work, Co-Cr-Mo alloy compacts with a unique bimodal microstructural design, harmonic structure design, were successfully prepared via a powder metallurgy route consisting of controlled mechanical milling of pre-alloyed powders followed by spark plasma sintering. The harmonic structured Co-Cr-Mo alloy with bimodal grain size distribution exhibited relatively higher strength together with higher ductility as compared to the coarse-grained specimens. The harmonic Co-Cr-Mo alloy exhibited a very complex deformation behavior wherein it was found that the higher strength and the high retained ductility are derived from fine-grained shell and coarse-grained core regions, respectively. Finally, it was observed that the peculiar spatial/topological arrangement of stronger fine-grained and ductile coarse-grained regions in the harmonic structure promotes uniformity of strain distribution, leading to improved mechanical properties by suppressing the localized plastic deformation during straining.
authors.affiliation: Research Organization of Science and Technology, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan. Electronic address: vajpaisk@gmail.com.
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Vajpai
authors.affiliation: Department of Industrial Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand. Electronic address: choncharoen@step.cmu.ac.th.
authors.forename: Choncharoen
authors.initials: C
authors.lastname: Sawangrat
authors.affiliation: Department of Mechanical Engineering, College of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan. Electronic address: rm0011xh@ed.ritsumei.ac.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamaguchi
authors.affiliation: A14, Materials Science Centre, University of Manchester, Manchester, M1 7HS, England. Electronic address: octav.ciuca@manchester.ac.uk.
authors.forename: Octav Paul
authors.initials: OP
authors.lastname: Ciuca
authors.affiliation: Department of Mechanical Engineering, College of Science and Engineering, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan. Electronic address: ameyama@se.ritsumei.ac.jp.
authors.forename: Kei
authors.initials: K
authors.lastname: Ameyama
mesh_terms: D000497:Alloys / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D006245:Hardness Tests; D008982:Molybdenum / Q000737:chemistry; D013718:Tensile Strength
chemical_list: D000497:Alloys; D002857:Chromium; D003035:Cobalt; D008982:Molybdenum
keywords: Bimodal grain structure; Co-Cr-Mo alloy; Deformation mechanism; Harmonic structure; Powder metallurgy; Severe plastic deformation