Layer-Graded Cu/B₄C/Graphite Hybrid Composites: Processing, Characterization, and Evaluation of Their Mechanical and Wear Behavior

Abstract

In this article, we synthesized and studied functionally graded multilayered Cu/B 4 C/graphite hybrid composites. Two classes of layer-graded composites were considered: pure Cu layer with two layers consisting of different particle sizes and uniform particle volume and a pure Cu layer with a single additional layer. The properties of the layer-graded composites were compared to those of single layer composites of two different particle sizes (1-20 mm and 60-90 mm). The composites were tested for compression strength, flexural strength, hardness, density, and wear and braking performance at a range of sliding speed conditions (5, 10, 30, and 35 m/s). The microstructure of the interfaces in the layergraded composites was characterized to determine the quality of bonding. We found that the layer-graded composites possess improved compression and flexural strength due to lower porosity and residual compressive stress in the composite layer aided by the work-hardening of the Cu layer. The presence of the ductile Cu layer improves the toughness and crack resistance properties of layer-graded composites by macrostructure toughening mechanism. The layer-graded composites possess improved wear resistance and braking performance at both low and high sliding speed conditions due to reduced third-body wear, oxidation, and softening of composites, aided by effective heat conduction through the Cu layer. Finally, the wear mechanisms operating at various speeds were discussed with the help of microscopic and X ray diffraction studies.

Effect of bimodal size particles reinforcement on the wear, friction and mechanical properties of brake composites

“…Most of the brake material studies on MMCs are Fe, Cu, Ni, Mg or Al-based MMCs with uniform size particle reinforcements. 12,[14][15][16][17][18][19][20][21][22][23][24][25] The factors influencing the wear and friction of MMCs are usually classified into two groups, one is the material and process parameters e.g. size, shape, volume fraction and size distribution of the particles, interface bonding strength, matrix type, type of processing and heat treatment, and other one is the testing conditions e.g.…”

Tribological and mechanical behaviour of dual-particle (nanoclay and CaSiO3)-reinforced E-glass-reinforced epoxy nanocomposites

“…These particles deviate and/or pin the cracks, retard its growth rate [34] and generate additional fracture surface area by making a tortuous path for crack propagation [7,[35][36][37][38][39]. This process demands additional consumption of energy for crack propagation [36][37][38][39]. Thus, the failure strain is improved in the composites filled with nanoparticles of the optimum amount.…”

A study on tribological behavior of Al-4%Mg incorporated with MoS2

“…Prabhu et al [12] described that Aluminium alloy− graphite particulate composites have importance as a self-lubricating material through the enhancement of the wear resistance, machinability and delayed onset of severe wear and seizure. Prabhu and vedantam [13] determined that the composite material attained through powder metallurgy process had attained inferior porosity with regulated stream of solid lubricant, however with extreme density ascribed to the deficiency of third-body wear which improved the braking function.…”