2.1.2.8 Modeling the Microhardness of Metal Matrix Composites.

MARIO ROBERTO ROSENBERGER; SCHVEZOV, C. E.; FORLERER, E.

San Diego, California, USA

Congreso; 15th International Conference on WEAR OF MATERIALS; 2005

WOM Steering Committee and Elsevier

The microhardness of metal matrix composites are affected by the presence of reinforcing particles in the subsurface of the material. The microhardness is directly related to the wear properties of the composite. In the present investigation a finite element method to model is developed to quantify the effect of the diameter of the indenter and the indentation depth in the indented diameter in the sample.  The model includes a spherical indenter, which is pressed against a soft metal like aluminum, which contains reinforcing particles. The results of the model are validated comparing the predicted values of indentation impression, the given properties of the model material and the standard impression given by the Brinell method. The results show a very good agreement between predicted and tabulated impressions. The model is employed as a first step, to predict indentation impressions in simple configurations of composites consisting of a matrix containing one particle of the same diameter as the indenter. The model is dynamic and simulates the constant load, which is applied during thirty seconds after which the indenter is retried. The diameters of the impression for reinforced and matrix materialsare compared, as well as the stress and strain fields in both materials. The results show that the impressions of reinforced materials are smaller than those for non-reinforced materials and the values depend on the position of the particle. The model results are discussed in relation with the resulting scatter of hardness values