Micromechanical modelling of ductile crack growth in the binder phase of WC–Co

Abstract This study focuses on numerical simulation of ductile failure in the Co binder phase of WC–Co hardmetal. The growth of edge cracks under mode I loading is considered. A computational micromechanics approach is taken where the Co binder ligaments are explicitly represented in finite element models. An embedding technique is employed. Crystal plasticity theory is used to represent plastic deformation in the Co ligaments. Crack propagation in the binder is simulated using an element removal technique based on a modified Rice and Tracey model for ductile void growth, and fracture resistance curves are generated. Parameter studies are performed for variations in microstructrual parameters such as numbers of Co ligaments ahead of the crack tip and local Co volume fraction. The importance of thermal residual stresses and finite element mesh density are also investigated.

[1]  S. Schmauder,et al.  Mesomechanical simulation of crack propagation through graded ductile zones in hardmetals , 1998 .

[2]  Peter E. McHugh,et al.  Simulation of void growth in WC-Co hardmetals using crystal plasticity theory , 1997 .

[3]  P. E. McHugh,et al.  Void growth simulations in single crystals , 1997 .

[4]  Siegfried Schmauder,et al.  Finite element modelling of crack propagation in WC-Co hard metals☆ , 1988 .

[5]  Peter E. McHugh,et al.  Analysis of the mechanical performance of a cardiovascular stent design based on micromechanical modelling , 2004 .

[6]  H. F. Fischmeister,et al.  FE-modelling of the deformation behaviour of WC-Co alloys , 1993 .

[7]  V. Tvergaard.  Influence of voids on shear band instabilities under plane strain conditions , 1981 .

[8]  Norman A. Fleck,et al.  Strain gradient crystal plasticity: size-dependentdeformation of bicrystals , 1999 .

[9]  Viggo Tvergaard,et al.  Influence of void nucleation on ductile shear fracture at a free surface , 1982 .

[10]  H. F. Fischmeister,et al.  On the fracture toughness of cemented carbides , 1988 .

[11]  H. Fischmeister,et al.  Prediction of crack paths in WCCo alloys , 1992 .

[12]  Robert H. Dodds,et al.  Ductile tearing in part-through cracks: experiments and cell-model predictions , 1998 .

[13]  Peter E. McHugh,et al.  Computational modeling of metal matrix composite materials. I: Isothermal deformation patterns in ideal microstructures , 1993 .

[14]  Xiaosheng Gao,et al.  Cell model for nonlinear fracture analysis – I. Micromechanics calibration , 1998 .

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

[16]  L. S. Sigl,et al.  Experimental study of the mechanics of fracture in WC-Co alloys , 1987, Metallurgical and Materials Transactions A.

[17]  Y. Lei,et al.  Mechanistic Prediction of Fracture Processes in Ferritic Steel Welds Within the Transition , 1998 .

[18]  Leon Mishnaevsky,et al.  Computational mesomechanics of particle-reinforced composites , 1999 .

[19]  Robert M. McMeeking,et al.  On the toughness of brittle materials reinforced with a ductile phase , 1988 .

[20]  Peter E. McHugh,et al.  Modelling of creep in a Ni base superalloy using a single crystal plasticity model , 1997 .

[21]  A. Nordgren.  Microstructural characterization of cemented carbides using SEM based automatic image analysis , 1991 .

[22]  N. Fleck,et al.  Strain gradient plasticity , 1997 .

[23]  J. Hancock,et al.  On the mechanisms of ductile failure in high-strength steels subjected to multi-axial stress-states , 1976 .

[24]  Alan Needleman,et al.  Material rate dependence and localized deformation in crystalline solids , 1983 .

[25]  Peter E. McHugh,et al.  Fracture modelling of WC-Co hardmetals using crystal plasticity theory and the Gurson model , 1999 .

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

[27]  M. S. Bruzzi,et al.  Micromechanical modelling of the static and cyclic loading of an Al 2124-SiC MMC , 2001 .

[28]  S. Schmauder,et al.  A finite element study of crack growth in WC-Co , 1988 .

[29]  H. Riedel,et al.  A LIQUID PHASE SINTERING MODEL: APPLICATION TO Si3N4 AND WC-Co , 1997 .

[30]  Yonggang Huang,et al.  A User-Material Subroutine Incorporating Single Crystal Plasticity in the ABAQUS Finite Element Program , 1991 .