Modeling of the densification of silver particles during sintering at controlled pressure and temperature

The control of the densification of a powder compact during the sintering process is of primary interest since this affects directly the obtained mechanical and physical properties. For example, silver sintering can be used to obtain joints for assembling optical or electronic components and, in such applications, an efficient thermal conductivity and a good material strength are requested. These properties are shown to be dependent on the density reached during compaction [1]. In our study, a well-established analytical model [2] is first employed to predict the main characteristics of the sintered material, such as the neck growth and the shrinkage during the initial stage of sintering. Effects of the temperature and the applied pressure are accounted for in the calculations, showing the ability of the model to find the optimal process parameters for some given objectives. The results are complemented with the densification estimation at the final stage of sintering obtained from a finite element simulation. The constitutive laws, which are implemented in the commercial code COMSOL Multiphysics, are based on a continuum approach of the sintered material as developed in [3,4]. (paper)