Phase stability and microstructural properties of high entropy alloy reinforced aluminium matrix composites consolidated via spark plasma sintering.

Spark plasma sintering (SPS) technique was employed in the consolidation of Cr20Mn20Ni20Cu20Nb10Co10 high entropy alloy (HEA) reinforced aluminium matrix composites. Phase stability and prediction expressions were used in the determination of the powder combination for the HEA. The microstructural analysis showed that an interdiffusion layer was formed between the aluminium matrix and the HEA particles in the sintered composites. Further investigation of the composites by X-ray diffraction (XRD) showed that in addition to the Al matrix phase present, other new phases (BCC, FCC and other intermetallics) were formed as a result of the reaction between the Al matrix and the atoms precipitated from the added HEA during sintering. The density of the HEA-reinforced Al matrix composites decreases with an increase in the wt.% of HEA from 98.6 % for pure aluminium to 98.1 % for the reinforced alloy with 10 % HEA, while the microhardness increases with an increase in the wt.% of the HEA from 35 HV for pure aluminium to 96.0 HV for the alloy reinforced with 10 % HEA.

Strength Characteristics of Electrospun Coconut Fibre Reinforced Polylactic Acid: Experimental and Representative Volume Element (RVE) Prediction.

Environmental conservation and waste control have informed and encouraged the use of biodegradable polymeric materials over synthetic non-biodegradable materials. It has been recognized that nano-sized biodegradable materials possess relatively good properties as compared to conventional micron-sized materials. However, the strength characteristics of these materials are inferior to fossil-based non-biodegradable materials. In this study, biodegradable polylactide (PLA), reinforced with treated coconut husk particulates (CCP) for improved mechanical properties, was fabricated using an electrospinning process and representative volume element (RVE) technique, and some of the obtained mechanical properties were compared. It was observed that the electrospun CCP-PLA nanofibre composites show improved mechanical properties, and some of these mechanical properties using both techniques compared favourably well. The electrospun fibres demonstrate superior properties, mostly at 4 wt.% reinforcement. Thus, achieving good mechanical properties utilising agro waste as reinforcement in PLA to manufacture nanocomposite materials by electrospinning method is feasible and provides insight into the development of biodegradable nanocomposite materials.