Hydroxyapatite is one of the most common bio-ceramic materials which is currently used in the biomedical field. The development of hydroxyapatite is due to their crystallographic and chemical similarity to the hard tissue of human body. The present study aims to prepare hydroxyapatite from a bio-waste material (carp fish bone) as an ecofriendly and inexpensive source by calcination treatment. The calcination process was applied at various calcining temperatures; the heating rate was kept constant at 10 °C min −1. FTIR results proved the formation of hydroxyapatite at 950 °C due to the founding peaks corresponding to phosphate (632 cm −1) and hydroxyl (3572 cm −1). XRD analysis confirmed the formation of HAp at 950 °C by the presence three main peaks: (211), (112), and (300), which correspond to the characteristic peaks of hydroxyapatite. Raman analyses which displayed the calcining process remove organic components from a bones matrix. AFM showed that the size of particles is ranged between nano and microns. EDS analysis found that the Ca/P reaches 1.6589 for fish bone after calcination at 950 °C, which is close to stoichiometric HAp (1.67).
Phase transformations in dissimilar resistance spot welds of dual phase steel and ferritic stainless steel are analysed. In contrast to a full martensitic microstructure predicted by the Schaeffler and Balmforth diagrams, a ferrite-martensite microstructure was observed in the fusion zone. The formation of ferrite phase in the fusion zone can be attributed to the rapid cooling rate of resistance spot welding, which suppresses the post-solidification ferrite-austenite transformation. The grain growth and martensite formation were main metallurgical features of the heat affected zone of ferritic stainless steel side. Microstructure gradient of heat affected zone in dual phase steel side was dictated by martensitic transformation. The effect of weld thermal cycle on the mechanical performance of the joint is discussed.
The paper aims at investigating the microstructure, failure mode transition, peak load and energy absorption of DP600 dual phase steel during the tensile-shear test. It was found that the welding current has profound effect on the load-displacement characteristics. In the low welding current, welds failed in interfacial failure mode. Increasing welding current resulted in sufficient weld nugget growth to promote double-sided pullout failure mode with improved mechanical properties. Further increase in the welding current caused expulsion and failure mode was changed to single-sided pullout with reduced energy absorption capability. It was found that the fusion zone size is the key parameter controlling the mechanical properties of DP600 resistance spot welds in terms of peak load, maximum displacement and failure energy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.