Evaluación de la tenacidad de fractura en aceros sinterizados de alta densidad.

This paper shows the methodology to assess fracture behaviour in sintered steels. Fracture toughness and the microstructure of PM steel (Fe-4.0Ni-1.5Cu-0.5Mo-0.5C) have been studied as a function of sintered density in a range from 7.20 to 7.51 g/cm³. Highest densities were achieved by warm compaction and double pressing-double sintering using three different lubricants. A quantitative analysis of microstructure was correlated with fracture behavior to assess the influence of pore morphology on mechanical properties. Fracture toughness increased with density, being this performance a remarkable advantage over wrought steels. Results showed that the enhanced behavior of the denser samples is due to improved distribution of more spherical porosity. In spite of using different lubricants, the final results depend solely on sintered density reached by each processing route. [ABSTRACT FROM AUTHOR]