On the mechanical behavior of sintered Astaloy-85Mo: Influence of porosity and sinter conditions

Astaloy (TM) 85 Mo is a pre-alloyed, water-atomized 0.85% Mo steel powder. The aim of the present investigation is to study the influence of porosity, controlled by both mechanical and thermal processing, on the mechanical properties in a bainitic microstructure of a pressed and sintered steel. To achieve this, uniaxial tensile and compression testing is performed, together with Vickers macro- and microhardness experiments. Microhardness testing is carried out in order to determine the behavior of the matrix material at a scale where porosity influence is minimized. Both the influence from size and shape of the pores is investigated and compared with relevant mechanical analyses for porous solids. Such mechanical analyses are pertinent to both elastic and plastic properties, where in the latter case the well-known Gurson-Tvergaard model for solids with spherical pores is relied upon. It is shown that assuming a spherical pore shape is not sufficient in order to achieve good agreement between predictions and experimental results and will be further investigated in future studies.

Automated summary

The aim of this study is to investigate the influence of controlled porosity on the mechanical properties of a bainitic microstructure. Uniaxial tensile and compression testing, as well as Vickers macro- and microhardness experiments, are used to determine the behavior of the matrix material. The results show that assuming spherical pores is not sufficient in predicting experimental results.