Role of Ultrasonic Treatment on Microstructure, Multiscale Mechanical, and Tribological Behavior of 2D Tungsten Disulfide Reinforced Aluminum Composites

This article is the first report on the role of ultrasonic treatment (UST) on microstructural evolution, multiscale mechanical behavior, and tribological response in 2D tungsten disulfide (WS2) reinforced aluminum (Al-6061) matrix composites. Delaunay triangulation calculations show that UST for 45 s enables a fourfold enhancement in the dispersion parameter of WS2 reinforcements in the Al-6061 matrix from 0.08 to 0.32. Improved WS2 dispersion contributes to higher nucleation density with 52.7% grain refinement efficiency, achieving a fine-grained Al-6061-WS2 composite. The role of UST-induced 2D reinforcement dispersion on the elastic deformation is established at progressively increasing length scales from individual grains to the bulk composite. It is accomplished by integrating the nanodynamic modulus mapping technique with a finite element modeling framework built on experimentally acquired microstructures and localized elastic moduli. It delineates a directly proportional relationship between UST-induced dispersion and elastic modulus enhancement at all length scales from 10 to 700 mu m. Excellent dispersion of the 2D layered WS2 homogenizes the tribological response of the composite material with a tenfold reduction in the volume of material lost during wear.