Powder metallurgy processes are able to form net-shaped products and are widely used in the production of automobile parts to improve productivity. The choice of powder materials and production processes, including mixing, compaction, sintering and heat treatment are critical to achieve the desired mechanical properties. Nevertheless, many times, the size and shape of the final products make impossible to extract standard specimens to analyze their mechanical properties and estimations based on other physical or chemical properties (i.e. density or carbon content) must be employed.
Hub synchronizers are quite small and have a geometry that does not allow determining their mechanical properties by means of standard specimens. Furthermore, their different constitutive parts (cube, radius and tooth) have different thicknesses and will behave in a different way.
The mechanical properties of the different parts of synchronizer hubs have been analyzed in this research work, using very small samples, by means of the small punch test (SPT). The “cube“ region was also characterized using miniature tensile specimens and the obtained results were compared with the SPT results. The provided correlation was then used to estimate the tensile properties of the other regions of the synchronizer hub and also to analyze the influence of different manufacturing variables, like the type of powder and graphite and the effect of applying a tempering treatment.