Structural and morphological analysis of zinc incorporated non-stoichiometric hydroxyapatite nano powders

In this study, Zn incorporated non-stoichiometric hydroxyapatite (nHAp) was synthesized via precipitation method and effect of the incorporation of Zn (fraction: 2, 4, 6 and 8 mol-%) on the microstructure of nHAp was studied by XRD, FTIR analysis and SEM-EDS techniques. The formation of nHAp was confirmed by XRD and FTIR those showed that no secondary phase was formed through the Zn incorporation. The SEM studies also revealed that particles were formed in nano-metric size (30-60 nm). It was found that crystallite and particle size of Zn incorporated nHAp gradually decreased up to 6 mol-%, and started to increase while the Zn fraction reached up to the 8 mol-% and hence the morphology of the aggregated products was also changed. It can be concluded that the incorporation of Zn cations cause to form nHAp phase. Furthermore, the nHAp microstructure has deviated from stoichiometric condition by incorporation of more Zn cations.Keywords: Microstructure; Nanopowder; Non-Stoichiometric Hydroxyapatite; Zn Incorporatio

Structural and morphological analysis of zinc incorporated non-stoichiometric hydroxyapatite nano powders

ABSTRACT In this study, Zn incorporated non-stoichiometric hydroxyapatite (nHAp) was synthesized via precipitation method and effect of the incorporation of Zn (fraction: 2, 4, 6 and 8 mol-%) on the microstructure of nHAp was studied by XRD, FTIR analysis and SEM-EDS techniques. The formation of nHAp was confirmed by XRD and FTIR those showed that no secondary phase was formed through the Zn incorporation. The SEM studies also revealed that particles were formed in nano-metric size (30-60 nm). It was found that crystallite and particle size of Zn incorporated nHAp gradually decreased up to 6 mol-%, and started to increase while the Zn fraction reached up to the 8 mol-% and hence the morphology of the aggregated products was also changed. It can be concluded that the incorporation of Zn cations cause to form nHAp phase. Furthermore, the nHAp microstructure has deviated from stoichiometric condition by incorporation of more Zn cations

Mechanically activated self-propagating high-temperature synthesis of titanium silicide-molybdenum disilicide composite using constituent elements

Silicides with potential to form a protective silica layer have garnered considerable attention as engineering ceramic materials. This research investigates the influence of initial composition and mechanical activation on the synthesis performance and microstructure of products in the Ti–Si–Mo system. Several compositions, including Ti8Mo29Si63, Ti15Mo25Si60, Ti22Mo22Si56, Ti40Mo12Si48, Ti52Mo6Si42, Ti62.5Si37.5, and Mo33Si67, were prepared and synthesized via mechanically activated self-propagating high-temperature synthesis (MASHS). XRD, SEM, and EDS analyses, along with related investigations such as grain size calculations and morphology studies, were performed. The results indicate that at low Ti concentrations, the composite contains (Ti0.8,Mo0.2)Si2 and MoSi2, whereas moderate Ti concentrations enable the formation of the MoSi2–Ti5Si3 composite. Moreover, a high amount of Mo can extensively dissolve into the titanium and titanium silicide structure, resulting in the synthesis of the (Ti,Mo)5Si3 phase in Ti-rich samples. The dissolution of Mo in the crystal structure of the compound decreases the lattice parameters of titanium silicide. Furthermore, mechanical activation facilitates the initiation of reactions in compositions with lower Ti content and yielding fine-grained products

Effect of milling time on XRD phases and microstructure of a novel Al67Cu20Fe10B3 quasicrystalline alloy

The quasicrystalline materials represent a new materials group with definite crystallite structural characteristics, in which the AlCuFe(B) quasicrystalline alloys have been widely studied owing to its various technological advantages such as easily accessible in nature, thermal stability, affordability as well as not having toxic constituent elements. Although these materials can be achieved by different procedures, the synthesis of more extensive amounts of AlCuFeB quasicrystalline single-phase powders is more complicated. In this study, the Al _67 Cu _20 Fe _10 B _3 quasicrystalline alloys were synthesized through the mechanical alloying process and afterward consolidated to the bulk specimens by cold isostatic pressing (CIP) technique. The structural and microstructural evolutions, as well as the morphology of as-milled powders and phase transformations, were studied during the ball milling process using field-emission scanning electron microscopy (FESEM) and x-ray diffractometry (XRD), while the thermal behavior was investigated using differential thermal analysis (DTA). The most fascinated result revealed that the stable AlCuFeB single quasicrystalline phase could be directly synthesized in short milling times (around ∼4 h) by a high-energy planetary ball milling. It was appreciated that the icosahedral phase is stable up to 300 °C, which is misplaced stability at superior temperatures and transforms into crystalline phases. The microhardness of consolidated ball-milled powders at various milling times was determined and it was figured out that the icosahedral phase has an extreme microhardness as much as 10.73 GPa