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A novel material formulation method of polylactic acid (PLA)/tubular clay nanocomposites via electrospinning was introduced and the important processing parameters such as solution concentration, clay loading, material feed rate were particularly investigated. The hybrid fibre diameter, the clay dispersability and the thermal properties of such nanocomposites were then characterised by using the scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC), respectively, to establish a fundamental structure-property relationship for the future application.

Poly (lactic acid) (PLA)/halloysite nanotubes (HNT) composite fibres were prepared by using a simple and versatile electrospinning technique. The systematic approach via Taguchi design of experiments (DoE) was implemented to investigate factorial effects of applied voltage, feed rate of solution, collector distance and HNT concentration on the fibre diameter, HNT non-intercalation and nucleation effects. The HNT intercalation level, composite fibre morphology, their associated fibre diameter and thermal properties were evaluated by means of X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), imaging analysis and differential scanning calorimetry (DSC), respectively. HNT non-intercalation phenomenon appears to be manifested as reflected by the minimal shift of XRD peaks for all electrospun PLA/HNT composite fibres. The smaller-fibre-diameter characteristic was found to be sequentially associated with the feed rate of solution, collector distance and applied voltage. The glass transition temperature (T g ) and melting temperature (T m ) are not highly affected by varying the material and electrospinning parameters. However, as the indicator of the nucleation effect, the crystallisation temperature (T c Appl. Phys. A (2013) 112: 747-757. nucleating agent role is confirmed when embedded with HNTs to accelerate the cold crystallisation of composite fibres. Taguchi DoE method has been found to be an effective approach to statistically optimise critical parameters used in electrospinning in order to effectively tailor the resulting physical features and thermal properties of PLA/HNT composite fibres.

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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.