Effect of long range order on mechanical properties of partially recrystallized Fe49Co-2V alloy

As shown in a previous publication, yield strength of Fe49Co-2V alloy depends on both boundary spacing and degree of order. In the present investigation, the effect of long range order (LRO) on the frictional stress has been emphasized. Neutrons diffraction measurements of LRO and SRO (short range order) of samples having the same microstructure and different yield strengths have shown changes on LRO, though, SRO remains stable. Consequently, the LRO has been found to be linearly dependent on the frictional stress, while no effect has been shown on the constant k, the slope of the Hall-Petch relationship. In parallel, from a data-gathering of our experimental results and those of literature, empirical equations of evolutions of both magnetic losses and yield strength as a function of boundary spacing and moreover that of the frictional stress as a function of LRO have been identified. Those equations have been compared to experimental evolution of losses as a function of yield strength, and as a result, a very good agreement between them has been found. Therefore, the best theoretical compromise between magnetic and mechanical properties has been calculated. Estimations demonstrate that optimal compromise is limited by the opposite effect of boundary spacing and LRO on magnetic losses and yield strength.