Microstructure and mechanical behavior of porous sintered steels

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2005-01, Vol.390 (1), p.98-112
• Main Authors: Chawla, N., Deng, X.
• Format: Article
• Language: English
• Subjects: Applied sciences; Elasticity. Plasticity; Exact sciences and technology; Fatigue; Fe–Mo–Ni steel; Finite element analysis; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Powder metallurgy; Tensile
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2004.08.046

The microstructure and mechanical properties of sintered Fe–0.85Mo–Ni steels were investigated as a function of sintered density. A quantitative analysis of microstructure was correlated with tensile and fatigue behavior to understand the influence of pore size, shape, and distribution on mechanical behavior. Tensile strength, Young's modulus, strain-to-failure, and fatigue strength all increased with a decrease in porosity. The decrease in Young's modulus with increasing porosity was predicted by analytical modeling. Two-dimensional microstructure-based finite element modeling showed that the enhanced tensile and fatigue behavior of the denser steels could be attributed to smaller, more homogeneous, and more spherical porosity which resulted in more homogeneous deformation and decreased strain localization in the material. The implications of pore size, morphology, and distribution on the mechanical behavior and fracture of P/M steels are discussed.