A multiscale approach to modeling the frictional behavior of the materials produced by additive manufacturing technologies

Additive manufacturing allows fabricatingmaterials with complex structures and specific properties. For Cu-Al alloys that are widely used in the sliding friction units of many machines in different industries, the 3D printing technique using electron beam-induced deposition seems to be very promising due to its great possibility in fabricating materials with varied compositions and gradient structure. The material structure and its surface properties play the most important role in frictional behavior. Friction is a very complex phenomenon, which includes a wide range of mechanical, physical, and chemical processes occurring at various scales simultaneously. Despite the great importance of friction, just a few restricted theories have been proposed till now. The same is valid for computer-aided simulation approaches. This paper presents a multiscale approach for modeling the mechanical behavior of the metallic materials in friction zone under sliding. This approach uses coupled discrete-continuum computational scheme in which a narrow contact zone of interacting bodies is described by the discrete element method and the rest of the material, which experiences elastic deformation, by the conventional finite element method of solid mechanics. Thus, at the mesoscale of friction that corresponds to contacting layers and third body we use computational particle mechanics. Here, special attention is given to describing the mechanical behavior of shape memory alloys that looks very promising for tribological applications of Cu-Al alloys. It is also shown that for obtaining some parameters of the mesomodel it is possible to use molecular dynamics simulation at the atomic scale. Finally, the results of friction simulation are considered and discussed for different values of the model parameters corresponding to the shape memory effect.