3D-modelling of the local plastic deformation and residual stresses of PM diamond-metal matrix composites

作者：Li B^*; Amaral P M; Reis L; Anjinho C A; Rosa L G; de Freitas M

来源：Computational Materials Science, 2010, 47(4): 1023-1030.

DOI：10.1016/j.commatsci.2009.12.001

• Diamond tools
• Plasticity
• Residual stresses
• Sintering process
• Finite element analysis

A computational strategy is developed to model the effects and interactions of non-metallic inclusions with metal bases. As an industrial case study, the present paper characterises the local elasto-plastic deformation and residual stress distribution induced through the sintering process of the diamond-metal matrix hot-pressed tool, which is a special metal matrix composite (MMC) reinforced by diamond particles, with average diameters ranging from 10 mu m to 0.5 mm, to increase the capability for cutting hard materials such as stones. The residual stress fields in the nearby region of a diamond particle via plastic deformation due to sintering process are examined to study the effects of the sintering temperatures and the compression pressure on the upper surface of the metal matrix during the sintering process. In the simulations, the metal matrix is modelled as an elastic-plastic material with combined isotropic-kinematic hardening. The diamond particle is modelled as isotropic and linear elastic. For simplicity, two geometries of the diamond particles are considered to study their effects on local plastic deformation and residual stress distributions. All simulations were performed using the ABAQUS finite element code. For the diamond particles embedded inside the metal matrix, 8-node axisymmetric quadrilateral, reduced integration ABAQUS solid element type CAX8 is used. For the diamond particles on the surface of the matrix, 4-node reduced integration ABAQUS solid element type C3D4 is used in the simulations. Simulating the sintering process and the cutting forces in service, it is demonstrated that the diamond retention capacity induced by the metal matrix (important for extending the life of a diamond tool) is mainly dependent on the sintering process. Optimum design of the diamond cutting tools can be achieved by selecting the appropriate sintering temperatures, the stress-strain behaviour of the metal matrix, the diamond particle shape and the compression pressure on the upper surface of the metal matrix during the sintering process.

• 出版日期2010-2