A dispersion strengthening model based on differing elastic moduli applied to the iron-copper system

Abstract A model is presented for the interaction between a matrix slip dislocation and a second phase particle of lower shear modulus than the matrix. From this model the minimum included angle reached by the arms of a dislocation while cutting the precipitate can be calculated as a function of the energy of the dislocation on either side of the precipitate/matrix interface. This angle is used to calculate the yield stress as a function of interparticle spacing. The model is tested using data from the iron-copper system. Experimental results relating the maximum yield strength to volume fraction of precipitate and the overaged yield stress to interparticle spacing show good agreement with the theoretical predictions. The low work-hardening rates observed in the iron-copper system are consistent with the predictions of the model.