Damage initiation and growth in metals. Comparison between modelling and tomography experiments

Abstract Damage in heterogeneous model materials was measured using high-resolution X-ray absorption tomography. The material consisted of an aluminium matrix containing 1% and 4% of spherical ceramic particles acting as nucleation sites for an interface decohesion mechanism of damage. The damage initiation stage was quantified using the global population of particles in the 4% material. A strain path change experiment was then applied to the 1% material. The sample was first deformed in tension in order to create elongated cavities and then compressed at 45 ∘ to rotate and close these cavities. The results of a model based on the Rice and Tracey approach accounting for the presence of particles inside the cavities and calculating their rotation with assuming a linear hardening plastic behaviour of the matrix were compared with the observations. The model was modified to account for the damage initiation phase. It was shown to give a good global prediction of the void volume fraction provided that the physical, mechanical and morphological information are corresponding in the experimental and the model cases. The cavity rotation experiment was also shown to compare well with the calculation although only one cavity was sufficiently opened after compression to allow the comparison.

[1]  F. M. Beremin.  Cavity formation from inclusions in ductile fracture of A508 steel , 1981 .

[2]  M. Elices,et al.  Particulate fracture during deformation , 1993, Metallurgical and Materials Transactions A.

[3]  D. M. Tracey,et al.  On the ductile enlargement of voids in triaxial stress fields , 1969 .

[4]  A. Gurson.  Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part I—Yield Criteria and Flow Rules for Porous Ductile Media , 1977 .

[5]  Peter Cloetens,et al.  Characterization of internal damage in a MMCp using X-ray synchrotron phase contrast microtomography , 1999 .

[6]  Yonggang Huang,et al.  Accurate Dilatation Rates for Spherical Voids in Triaxial Stress Fields , 1991 .

[7]  Laurent Babout,et al.  Characterization by X-ray computed tomography of decohesion, porosity growth and coalescence in model metal matrix composites , 2001 .

[8]  John W. Hutchinson,et al.  Void Growth and Collapse in Viscous Solids , 1982 .

[9]  B. J. Lee,et al.  Axisymmetric deformation of power-law solids containing a dilute concentration of aligned spheroidal voids , 1992 .

[10]  J. D. Embury,et al.  Tensile and bending properties of AA5754 aluminum alloys , 2001 .

[11]  C. Verdu,et al.  A study of physico-chemical mechanisms responsible for damage of heat treated and as-cast ferritic spheroïdal graphite cast irons , 1996 .

[12]  Thomas Pardoen,et al.  An extended model for void growth and coalescence - application to anisotropic ductile fracture , 2000 .

[13]  N. Fleck,et al.  Void growth in shear , 1986, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[14]  Laurent Babout,et al.  Damage initiation in model metallic materials: X-ray tomography and modelling , 2004 .

[15]  Jean-Baptiste Leblond,et al.  Approximate Models for Ductile Metals Containing Nonspherical Voids—Case of Axisymmetric Oblate Ellipsoidal Cavities , 1994 .

[16]  Y. Dafalias.  Issues on the constitutive formulation at large elastoplastic deformations, part 2: Kinetics , 1987 .

[17]  A. Needleman,et al.  Analysis of the cup-cone fracture in a round tensile bar , 1984 .

[18]  Jacques Besson,et al.  Plastic potentials for anisotropic porous solids , 2001 .

[19]  E. Maire,et al.  On the application of x-ray microtomography in the field of materials science , 2001 .

[20]  A. Needleman,et al.  Void Nucleation Effects in Biaxially Stretched Sheets , 1980 .

[21]  P. Thomason,et al.  Ductile Fracture of Metals , 1990 .

[22]  J. Llorca,et al.  Fracture toughness and fracture mechanisms of Al-Al2O3 composites at cryogenic and elevated temperatures , 1996 .

[23]  Pedro Ponte Castañeda,et al.  A general constitutive theory for linear and nonlinear particulate media with microstructure evolution , 1998 .

[24]  Amit K. Ghosh,et al.  Cavitation during hot tension testing of Ti–6Al–4V , 1998 .

[25]  B. Bilby,et al.  The finite deformation of an inhomogeneity in two-dimensional slow viscous incompressible flow , 1977, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[26]  Jean-Baptiste Leblond,et al.  An improved Gurson-type model for hardenable ductile metals , 1995 .