Search Results

Due to their favorable properties, among them the excellent strength-to-weight ratio, aluminum alloys are applied in transport vehicles, like trucks and buses. With respect to their mechanical behavior, fatigue is a process that alters the life of a structural component producing local stresses and floating strains and consequently giving rise to crack nucleation and the fracture of the material. In this work it is shown the influence of microstructure and intermetallic particles in aluminum alloy AA6005-T6, AA6063-T6 and AA6351-T6 that were tested for tension and fatigue. The microconstituents and the crack path on the fracture surfaces were analyzed by optical microscopy and scanning electron microscopy (SEM). The variation of the geometry of the precipitated particles of Mg₂Si, intermetallics (Fe,Mn)₃SiAl₁₂ and irregular distribution of particles in the matrix of the alloys were observed.

The aim of the present work is to analyse the microstructural changes caused by distinct heat treatments and their relationships with the mechanical properties of a recently developed microalloyed steel with 0.08%C-1,5%Mn. This steel, designated as B550, is being considered as a promising alternative to replace the low carbon steel in some wheel`s components for the automotive industry. Various multiphase microstructures with different amounts of ferrite, martensite, bainite and retained austenite were obtained by means of heat treatments conducted at distinct temperatures. Tensile tests allowed evaluating the mechanical properties of the various material conditions. The experimental results showed that water quench from 800°C results in a better combination of mechanical properties of strength, hardenability and ductility.