First development to model aerosol emission from engineering materials subjected to mechanical stresses
Résumé
Many studies have shown that when the surface of traditional and nanostructured materials are subjected to mechanical stress, aerosolization of wear particles can occur (Shandilya et al., 2014a). Such an aerosol comprises of nano and micro particles which are prone to human interactions, either through their inhalation or dermal contact. To expand our knowledge on the release mechanisms of these particles, an attempt has been made to develop a mathematical model. Thanks to prior studies (Le Bihan et al. 2013, Shandilya et al. 2014b, Morgeneyer et al. 2015), this model considers an original and multidisciplinary approach that links different constitutive equations in Tribology, Material and Aerosol physics. Among other hypotheses, a Rossin-Rammler distribution is used to approximate the size distribution of generated abrasion wear particles in nanosize range (≤10-7 m). It is normally used to fit the size distribution of microparticles, generated during the fragmentation of rocks. Furthermore, the generated wear particles are hypothesized to be spherical in shape and their aerosolization probability depends upon its size, density, environmental conditions and the net mechanical force input. The experimental data showed varying levels of generated aerosol particles which primarily depends upon the type of material getting abraded i.e. it can be high (e.g. in case of brick and ceramic) as well as contrastingly low (e.g. in case of steel). This variability, observed in the experimental data, is also predicted by the model. A sensitivity analysis was also conducted to determine the relative importance of various key parameters (like material, process and environment parameters).