Hot working analysis of a CuZn40Pb2 brass on the monophasic (β) and intercritical (α plus β) regions

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:627

Article

Suarez, L.^1,2  Rodriguez-Calvillo, P.^1,2  Cabrera, J. M.^1,2  Martinez-Romay, A.³  Majuelos-Mallorquin, D.³ 

[1] Univ Politecn Cataluna, Dept Ciencia Mat & Ingn Met, E-08028 Barcelona, Spain

[2] Fundacio CTM Ctr Tecnol, Manresa 08243, Barcelona, Spain

[3] GENEBRE SA, Lhospitalet De Llobregat 08908, Spain

关键词: Hot working;    Constitutive equations;    Intercritical region;    Brass;   

DOI  :  10.1016/j.msea.2014.12.093

来源: Elsevier

【 摘 要 】

The high temperature deformation behavior of a Cu4OZn2Pb brass was studied by means of compression and tensile tests in the beta monophasic and alpha/beta biphasic regions. The ductility evaluated in terms of elongation and area reduction allowed to distinguish three regions: one 13 monophasic region (above 720 degrees C), and two alpha/beta biphasic regions, between 720 degrees C and 600 degrees C, and below 600 degrees C. The fracture appearance was evolving from a ductile type, with dimple formation, to a more brittle one with grain decohesion as the deformation temperature was decreased or the amount of 13 phase reduced. The apparent creep exponent values for the peak and steady stresses were close to 4 and 3, respectively, indicating that the glide and climb of dislocations and grain boundary sliding were the main controlling deformation mechanism, respectively. On the other hand the apparent activation energy values for the peak and steady stresses were 268.83 +/- 11.64 and 254.9 +/- 20.62 kJ/mol; respectively, being all well above the self-diffusion activation energy values of either Cu (1971(kJ/mol) or Zn (91.7 kJ/mol). The modeling of the flow curves was carried out by physically-based constitutive equations considering the coexistence of recovery, work hardening and recrystallization on a two-phase material. The 13 phase, rich in Zn, enhanced the dynamic recovery and retarded the recrystallization kinetics, while the opposite was determined for the a phase, rich in Cu. (C) 2015 Elsevier B.V. All rights reserved.

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