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This article deals with fabrication and machinability analysis of squeeze cast Al 7075/h-BN/Graphene hybrid nanocomposite (HNC), which has been fabricated by reinforcing hexagonal boron nitride (0.5 wt% h-BN) and graphene nanoparticles (1 wt% GNPs). In order to utilize the self-lubricating property of h-BN and GNPs, their uniform mixing is essential, hence before squeeze casting of HNC ball milling (BM) technique has been employed which enables uniform mixing and also eliminates the agglomeration effect of nanoparticles. Scanning electron microscopy (SEM) and optical microscopic (OM) investigation confirm the uniform mixing of nanoparticles as well as refinement in the grain size. In order to examine the hardness of the proposed HNC, mechanical properties were investigated and observed improvement of 31.25%, 10.93% and 10.27% in the UTS, microhardness (Vickers) and Rockwell hardness respectively as compared to unreinforced Al 7075 alloy fabricated by stir casting. Based on the obtained results machinability analysis is performed considering numerous machining process parameter during CNC turning to investigate the influence of cutting speed (CS), feed rate (FR) and depth of cut (DOC) on surface roughness (SR), generated forces, tool wear and chip morphology of squeeze cast HNC subjected to dry and minimum quantity lubrication (MQL) machining. Finally, the acquired results are presented with the aid of comparative graphical presentation with squeeze casted conventional aluminium alloy.

The current study deals with the replacement of existing sintered bronze brake pad using hybrid composite brake pads for armour vehicle application. In the present work, fused mullite was added in three different weight percentages which was compensated by synthetic barites. The pads were produced by conventional manufacturing procedure. The physical and mechanical properties were measured as per industrial standards. The tribological performance was evaluated using Chase test following IS2742 Part-4 standards. The test results showed that 3 wt% of mullite abrasive in hybrid brake pad formulation produced reduced density, less squeal, less frictional undulations with the minimum wear of 0.887 g for 100 brake applications. Worn surface characteristics were analysed using scanning electron microscopy.

Copper-based sintered friction materials are most suitable for heavy-duty off-road vehicles, trains, aircraft, and military applications. This present study aims to investigate the tribological performance, dominating wear mechanism of an existing copper-tin sintered friction material that is being used in armoured fighting vehicle. The brake pad was tested as per IS 2742 using the chase test machine. Especially fade cycle was carried out till 441℃ to analyze the frictional response of the material. Physical, mechanical, and tribological properties were evaluated as per industrial standards. Morphological analysis was carried out using field emission scanning electron microscopy, and wear debris analysis was carried out using scanning electron microscopy–energy dispersive X-ray analysis and X-ray diffraction analysis. The dominating wear mechanisms were found to be delamination and abrasive wear. The investigated results showed a less wear rate of 0.05 cm3/MJ. However, results seem to be better for high-energy applications by exhibiting excellent mechanical properties.

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In the original publication of the article, Fig. 7 has been wrongly overwritten with Fig. 8. The correct Fig. 7 is given below, and the original article has been updated accordingly. Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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