A Mixed Hardening Model of Ultrafine-grained Materials and Numerical Simulation

Equal-channel angular pressing (ECAP) is a convenient processing method for refining the grain size of bulk materials to the submicrometer level. Metallic alloys processed by ECAP often exhibit excellent superplastic characteristics including superplasticity at high strain rates. This paper summarizes recent experiments designed to evaluate the occurrence of superplasticity in representative aluminum and magnesium alloys and in the Zn-22% Al eutectoid alloy.

Download Full-text

Modelling and numerical simulation of thick sheet double slitting process using continuum damage mechanics

International Journal of Damage Mechanics ◽

10.1177/1056789514520799 ◽

2014 ◽

Vol 23 (8) ◽

pp. 1150-1167 ◽

Cited By ~ 7

Author(s):

Yosr Ghozzi ◽

Carl Labergere ◽

Khemais Saanouni ◽

Anthony Parrico

Keyword(s):

Numerical Simulation ◽

Constitutive Equations ◽

Damage Mechanics ◽

Continuum Damage Mechanics ◽

Thick Sheet ◽

Technological Parameters ◽

Strongly Coupled ◽

Mixed Hardening ◽

Elasto Plasticity ◽

Fully Coupled

This work concerns the modelling and numerical simulation of specific thick sheet cutting process using advanced constitutive equations accounting for elasto-plasticity with mixed hardening fully coupled with isotropic ductile damage. First, the complex kinematics of the different tools is modelled with specific boundary conditions. Second, the fully and strongly coupled constitutive equations are summarized and the associated numerical aspects are shortly presented. An inverse material identification procedure is used to determine the convenient values of the material parameters. Finally, the double slitting process is numerically simulated and the influence of the main technological parameters studied focusing on the cutting forces.

Download Full-text

The New SPD Processing Trends to Fabricate Bulk Nanostructured Materials

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.114.7 ◽

2006 ◽

Vol 114 ◽

pp. 7-18 ◽

Cited By ~ 3

Author(s):

Ruslan Valiev

Keyword(s):

Plastic Deformation ◽

Severe Plastic Deformation ◽

Grain Refinement ◽

Nanostructured Materials ◽

Nanocrystalline Materials ◽

Commercial Production ◽

Materials Processing ◽

Ultrafine Grained ◽

Ultrafine Grained Materials ◽

Bulk Nanocrystalline

During the last decade severe plastic deformation (SPD) has become a widely known method of materials processing used for fabrication of ultrafine-grained materials with attractive properties. Nowadays SPD processing is rapidly developing and is on the verge of a transition from lab-scale research to commercial production. This paper focuses on several new trends in the development of SPD techniques for effective grain refinement, including those for commercial alloys and presents new SPD processing routes to produce bulk nanocrystalline materials.

Download Full-text

Improvement of formability of ultrafine-grained materials by post-SPD annealing

Materials Science and Engineering A ◽

10.1016/j.msea.2014.09.016 ◽

2014 ◽

Vol 619 ◽

pp. 119-128 ◽

Cited By ~ 20

Author(s):

O. Saray ◽

G. Purcek ◽

I. Karaman ◽

H.J. Maier

Keyword(s):

Ultrafine Grained ◽

Ultrafine Grained Materials

Download Full-text

The Processing of Ultrafine-Grained Materials Using High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.558-559.1283 ◽

2007 ◽

Vol 558-559 ◽

pp. 1283-1294 ◽

Cited By ~ 1

Author(s):

Cheng Xu ◽

Z. Horita ◽

Terence G. Langdon

Keyword(s):

Plastic Deformation ◽

Grain Size ◽

High Pressure ◽

High Pressure Torsion ◽

Metallic Materials ◽

Grain Sizes ◽

Ultrafine Grained ◽

Wide Range ◽

Ultrafine Grained Materials ◽

Thin Disks

It is now well-established that processing through the application of severe plastic deformation (SPD) leads to a significant reduction in the grain size of a wide range of metallic materials. This paper examines the fabrication of ultrafine-grained materials using high-pressure torsion (HPT) where this process is attractive because it leads to exceptional grain refinement with grain sizes that often lie in the nanometer or submicrometer ranges. Two aspects of HPT are examined. First, processing by HPT is usually confined to samples in the form of very thin disks but recent experiments demonstrate the potential for extending HPT also to bulk samples. Second, since the strains imposed in HPT vary with the distance from the center of the disk, it is important to examine the development of inhomogeneities in disk samples processed by HPT.

Download Full-text