Title: Synthesis and mechanical characterisation of self-lubricating Al7075/MoS₂/ZrB₂ hybrid composite

Authors: Mukesh Dubey; Narendra Kumar; Sunil Mohan

Addresses: Dr. APJ Abdul Kalam Technical University, Lucknow, Uttar Pradesh 226031, India ' Department of Mechanical Engineering, B.I.E.T., Jhansi, India ' Department of Metallurgical Engineering, I.I.T. (BHU), Varanasi, India

Abstract: In the current study, Al7075-based hybrid composites reinforced with zirconium diboride (ZrB₂) and molybdenum disulphide (MoS₂) particles were synthesised through a two-step stir casting process. Three distinct compositions Al7075 alloy, Al7075 + 3 vol.%MoS₂ and Al7075 + 3 vol.%MoS₂ + 3 vol.%ZrB₂ have synthesised using the stir casting process. X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM) along with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and mechanical characterisation were performed on all synthesised samples to identify reinforcement particles, grain refinement, particle morphology, hardness, tensile properties and failure mode. Microstructural examination reveals refined grain structure, uniform distribution of particles, along with clear interface and good bonding. Mechanical characterisation reveals Al7075/MoS₂/ZrB₂ hybrid composite with highest hardness, strength, and ductility among all the compositions examined. Increased strength along with good ductility of composite over the unreinforced alloy is an important finding of the present study in contrast with many previous studies. Microstructure and mechanical features were correlated with results obtained for enhanced performance and life span of the hybrid composites.

Keywords: hybrid composite; Al7075; zirconium diboride; ZrB₂; molybdenum disulphide; MoS₂; stir casting; mechanical properties.

DOI: 10.1504/IJMPT.2023.127956

International Journal of Materials and Product Technology, 2023 Vol.66 No.1, pp.1 - 16

Received: 28 Sep 2021
Accepted: 03 Mar 2022
Published online: 22 Dec 2022 *