Experimental and numerical analysis of the deformation of ferrite segments during sintering

The thermo-mechanical behaviour of hard ferrite powder compacts at high temperature is investigated with a view to simulating dimensional changes occurring during sintering of industrial components. Emphasis is laid on the anisotropy in both shrinkage and viscosity, which is induced by the prior pressing operation performed under magnetic field. Anisotropic shrinkage and viscosity are described according to an original approach based on an orthotropic thermo-elastic equation, which assumes an analogy between the thermal and elastic terms of this equation and the viscous and free sintering deformations. Finite element calculations using this constitutive equation are then carried out on two industrial parts. The comparison between the obtained numerical results and experimental measurements proves the relevance of the proposed model.