摘要：Surface modification and coating techniques are widely used to improve tribological properties of metallic materials for a wide range of manufacturing, transportation, defense, and consumer industries. However, in all these techniques a surface treatment is applied after the part has been fabricated, and this adds significantly to the overall costs. An alternative, costeffect method has been, proposed via functionalization of aluminum matrix composites uniformly reinforced with hard particles. A larger volume fraction of those particles can be attained near the wear surface via centrifugal casting,. The volume fraction of the heavier borides is controlled by inertial forces upon centrifugal processing the semisolid composite. In this study, boride particles are modeled as spherical particles subject to a drag force in a Stoke flow in the liquid aluminum matrix. This equation of motion for the particles under the applied centrifugal forces is solved numerically assuming a gaussian diameter size distribution with a spatial uniform random distribution of particles in the sample. The effect of temperature on the viscosity is also considered by solving the energy equation. From parametric studies in the numerical model, it is possible to better understand and control the experimental conditions to obtain an appropriate functionally-graded aluminum matrix for high wear resistance applications.
其他摘要：Surface modification and coating techniques are widely used to improve tribological properties of metallic materials for a wide range of manufacturing, transportation, defense, and consumer industries. However, in all these techniques a surface treatment is applied after the part has been fabricated, and this adds significantly to the overall costs. An alternative, costeffect method has been, proposed via functionalization of aluminum matrix composites uniformly reinforced with hard particles. A larger volume fraction of those particles can be attained near the wear surface via centrifugal casting,. The volume fraction of the heavier borides is controlled by inertial forces upon centrifugal processing the semisolid composite. In this study, boride particles are modeled as spherical particles subject to a drag force in a Stoke flow in the liquid aluminum matrix. This equation of motion for the particles under the applied centrifugal forces is solved numerically assuming a gaussian diameter size distribution with a spatial uniform random distribution of particles in the sample. The effect of temperature on the viscosity is also considered by solving the energy equation. From parametric studies in the numerical model, it is possible to better understand and control the experimental conditions to obtain an appropriate functionally-graded aluminum matrix for high wear resistance applications.
