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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).

The present study investigates comparison between corrosion behavior of 2507 and 2205 DSS in artificial saliva for orthodontic wires. The heat treatment is necessary for 2507 and 2205 duplex stainless steel to remove or dissolve intermetallic phases, removed segregation and to relieve any residual thermal stress in DSS which may be formed during production processes. The corrosion behavior of a 2507 and 2205 DSS in artificial saliva was studied by SEM, HV test and potentiodynamic measurements. The results indicate that the corrosion resistance mainly depends on presence of secondary phases (sigma phase) and ferrite /austenite ratio, it's revealed that the corrosion resistance of 2507 DSS higher than 2205 DSS in artificial saliva at 37 °C.

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Hydroxyapatite (HAp) is one of the vital and bioactive materials that are commonly used in biomedical field and concentrated in clinical area. It is a bio-ceramic powder synthesized by using different bio-waste materials such as bovine femur bone. In this study, the bovine femur bone powder was prepared to obtain nano powder. The purpose of this study was to reach the optimal temperature to obtain nanoparticles HAp. The resulted powder was calcinated in a furnace at different temperatures (900, 950, 1000, 1050 and 1100 °C) for 2 h at the heating rate of 10 °C/min and cooled slowly in a furnace. Results showed, the formation of pure HAp by the presence of peaks corresponding to (PO 4 ) 3-at 632/cm and OH -at 3,572/cm in fourier transformation infrared spectroscopy (FTIR). For the calcined samples, there were three main peaks of 211, 112 and 300 planes at 2θ near 31.8, 32.2 and 32.9 respectively. The amorphous raw bones were transformed into crystalline phase and the lattice parameters for HAp c and a were calculated in X-ray diffraction (XRD), Raman analysis showed that the calcination process removed the organic compound from the bovine femur bones matrix. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) showed that the shape of the granules was irregular, containing quantities of oxygen, magnesium, sodium and carbon; the ratio of calcium to phosphate was calculated, Atomic force microscopy (AFM) showed that the particles sizes ranged from nanometers to microns. EDX result found that the calcium to phosphate ratio reached 1.7058 after calcination at 950 °C which was close to stoichiometric hydroxyapatite (1.67). This result implied the formation of pure HAp phase at 950 °C.