Vacuum degassing and actions of lithium fluoride on microstructural and mechanical properties of LM25 alloy composite embedded with carbide/oxide nanoparticles

Aluminium alloy (LM25) hybrid nanocomposite is familiar in lightweight automotive frames, heat exchangers, and heavy-duty machining parts applications because of its excellent fluidity, mechanical properties, and superior corrosion resistance. The stir-casting method is often used to create intricate designs. However, it has been disputed that degassing causes porosity to form, poor wettability causes particle agglomeration, and microstructure non-homogeneity restricts the functional qualities of composites. The primary goal of the study is to create a high-quality LM25 alloy hybrid nanocomposite with 3 wt% boron carbide (B4C) and 1–5 wt% alumina (Al2O3) nanoparticles using a stir cast process that overcomes the primary issue with liquid stir cast by using vacuum degassing with an applied vacuum pressure of 1X105 Pa, 0.1 wt% lithium fluoride (LiF), and 20 kHz Ultrasonication. The B4C/Al2O3 nanoparticles have a homogeneous and agglomeration-free structure, and the effects of vacuum degassing, wettability agents, and the Ultrasonication treatment on microstructural behaviour are examined using a Hi-Resolution Transmission Electron Microscope (HRTEM). Furthermore, the impact of hybrid filler on mechanical and physical characteristics is investigated. The LM25/3 wt% B4C/5 wt% Al2O3 hybrid nanocomposite has demonstrated a marginal improvement in actual density (2.3 g/cm3), decreased porosity ( < 1%), enhanced tensile strength performance (335MPa), enhanced impact toughness (12.5J/mm2), and a higher Vickers hardness number (98HV), as per the results of the investigation. Optimum properties of LM25/3 wt% B4C/5 wt% Al2O3 hybrid nanocomposite will be suggested for applications involving lightweight automotive frames.