Analysis of the mechanical, thermal and frictional behavior of Cu-sepiolite composite materials

To enhance the wear resistance of copper, sepiolite was used as a reinforcing element to explore the interface bonding strength between both. A comprehensive analysis was conducted from mechanical, thermal, and frictional perspectives to elucidate the role of sepiolite in copper. The results reveal that the interface between both remains undamaged under the applied loads of 0.4 N, with only minimal plastic deformation. However, excessive interface formation could compromise the continuity of the copper, resulting in reduced structural densification and impeded thermal conductivity. Moreover, sepiolite exhibited a particle strengthening effect, improving the mechanical strength. In which, H2 (20% sepiolite) exhibited the most significant characteristics, featuring a dense structure, small pores, and high shear strength and thermal conductivity, particularly excelling in Brinell Hardness (81.9HB). However, the frictional performance varied, gradually strengthening with the increasing amount of sepiolite. Notably, sepiolite acts as micro-protrusions to counteract friction forces. Partially fragmented sepiolite adheres to the friction surface, forming a mixed layer that facilitates the abundant generation of Cu ₂O. Besides, the CaCO ₃ in sepiolite undergoes thermal decomposition, resulting in the formation of CaO, both of which also function as micro-protrusions.