The role of in-situ ceramic reinforcements on microstructure evolution and mechanical properties on developed hybrid Mg-MMCs

Kumar

Journal of Composite Materials

2020

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Present work aims at developing Magnesium based metal matrix composite (MMC) through in-situ reaction. In-situ generation of micro and nano particles in the Mg-melt is supposed to have a better bonding with the matrix. Ceric ammonium nitrate (CAN) is added to initial Magnesium melt (with an aim to generate CeO2 and MgO through in-situ reaction) at temperatures of 670 °C and 870 °C. The developed MMCs are solution treated to get rid of intermetallic. The nature of particles is explored with X-ray diffraction (XRD) and Energy dispersion spectroscopy (EDS). The morphology and sizes of particles are keenly jotted using scanning electron microscope (SEM). Mechanical responses of developed MMCs are recorded through Hardness, Compression and scratch tests. The compression fractured surfaces are analyzed with SEM and scratched samples are analyzed on 3 D optical profilometer to explore deformation behavior. The observations indicate the in-situ formation of CeO2, MgO and CeMg12 intermetallic phases in different types and sizes. Further, these particles are responsible for improved mechanical properties. The findings are supported by the contribution of different strengthening mechanisms.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of magnesium-based hybrid metal matrix composite through in situ micro, nano reinforcements

Kumar

Journal of Composite Materials

2020

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“…The morphology of adhered platelets on the surface of heparin functionalized stents was examined by SEM as present in Figure 11. In comparison to the previous literature (Singh et al , 2020), it was observed that platelet adhesion was remarkably reduced after functionalization of heparin on the surface of Art18z, Palmaz-Schatz and Abbott Bvs1.1 stents, as revealed in Figure 11 (Singh et al , 2020). The reduction in platelets attachment was due to charge repulsion as negative charge was induced due to heparin functionalization.…”

Section: Biological Characterizationsmentioning

confidence: 39%

“…It was also observed from Figure 11 that the adhered platelets did not represent any dendritic or fibrous structure around which reflected zero activation of the platelets. Thus, the results revealed that heparin functionalization was more effective to reduce the platelet adhesion and activation (Singh et al , 2020).…”

Section: Biological Characterizationsmentioning

confidence: 99%

“…In the present investigation, SC3P technique was used to fabricate the polymeric stent by blending PCL and iron pentacarbonyl powder (CIP). In the previous investigations, PCL/CIP blend had been acknowledged as a trustworthy material for cardiovascular application (Singh et al , 2020, 2021). Besides good mechanical characteristics, CIP was used as a blending material because of its biocompatible and hemocompatible behavior (Oriňaková et al , 2016; Zhao et al , 2009).…”

Section: Introductionmentioning

confidence: 99%

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Effect of heparin drug loading on biodegradable polycaprolactone–iron pentacarbonyl powder blend stents fabricated by solvent cast 3D printing

Pandey

Kaur

et al. 2022

RPJ

Purpose The purpose of this paper is to fabricate pre-existing geometries of the stents using solvent cast 3D printing (SC3P) and encapsulation of each stent with heparin drug by using aminolysis reaction. Design/methodology/approach The iron pentacarbonyl powder and poly-ɛ-caprolactone blend (PCIP) were used to print stent designs of Art18z, Palmaz-Schatz and Abbott Bvs1.1. The properties of antithrombosis, anticoagulation and blood compatibility were introduced in the stents by conjugation of heparin drug via the aminolysis process. The aminolysis process was confirmed by energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy due to presence of amide group and nitrogen peak in the respective analysis. Biological studies were performed to depict the cell viability, hemocompatibility and antithrombotic properties. Besides, mechanical behaviors were analyzed to study the behavior of the stents under radial compression load and bending load. Findings The amount of heparin immobilized on the Art18z, Palmaz-Schatz and Abbott Bvs1.1 stents were 255 ± 27, 222 ± 30 and 212 ± 13 µg, respectively. The cell viability studies using L929 fibroblast cells confirmed the cytocompatibility of the stents. The heparinized SC3P printed stents displayed excellent thrombo-resistance, anticoagulation properties and hemocompatibility as confirmed by blood coagulation analysis, platelet adhesion test and hemolysis analysis. Besides, mechanical behavior was found in context of the real-life stents. All these assessments confirmed that the developed stents have the potential to be used in the real environment of coronary arteries. Originality/value Various customized shaped biodegradable stents were fabricated using 3D printing technique and encapsulated with heparin drug using aminolysis process.

Reinforcing the Near Eutectic Aluminum–Silicon Alloy with Graphene: An Approach toward Self‐Lubricating Composite

Kumar

et al. 2020

Adv Eng Mater

Self Cite

Mechanical and physical properties of aluminum alloys make them suitable for automotive and other structural applications. The high silicon content in aluminum improves the hardness to a great extent but at the cost of ductility. Herein, the reinforcement of near eutectic Al–Si (ADC12) alloy with the reduced graphene oxide (rGO) is demonstrated. The ADC12 alloy and its composite with rGO are cast using the gravity stir die‐casting process. The structural, mechanical, metallurgical, and tribological characteristics are conducted to understand the role of rGO as a reinforcement phase. The 0.7 wt% rGO as a reinforcement phase to ADC12 alloy reduces the friction and wear volume by 50% and ≈90%, respectively, whereas it improves the hardness by 27%. The high‐resolution transmission electron microscopy (TEM) image reveals the wrapping of microstructural silicon by rGO, which inhibits the growth of primary silicon and improves the interfacial strengthening. The high mechanical strength and low shearing properties of rGO, uniform dispersion in the ADC12 alloy, and restrained growth of primary silicon make the ADC12 alloy‐based composites potential materials for structural and low‐frictional building blocks in a diversified range of applications.