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X-ray fluorescence provides a powerful means of non-destructively determining the elemental composition of a sample. X-rays from a Molybdenum (Mo) source was fired on copper, molybdenum, lead, steel and brass samples to determine their composition and relative abundance of their constituent elements. Two different detectors : the Cadmium Telluride (CdTe) and Silicon(Si) detectors were used to pick up the signals from the scattering of the X-rays at the sample surfaces and their energy resolutions as well as efficiencies were compared. With a non-noisy amplifier, the Si detector had a higher resolution (0.27 % ) when compared to the 0.38 % for the CdTe detector but it had a lower efficiency when compared to that of the CdTe detector. It was also discovered that higher energies produced lower detector efficiencies. [ABSTRACT FROM AUTHOR]

Poor formability and corrosion resistance are the limitations that restrict the widespread applications of biodegradable magnesium alloys as surgical staples. In this study fine-grained Mg–2Zn-0.5Nd (ZN20) alloy wire with a diameter of 0.23 mm was fabricated by a combination of equal-channel angular pressing (ECAP), friction stir processing (FSP), extrusion and hot drawing. ECAP could be beneficial to the subsequent deformation by texture weakening, and FSP could improve the corrosion resistance by decreasing the number of second phases. A typical microstructure with similar diameter of matrix grains and second phase particles was observed in ZN20 alloy wire after combined processing of ECAP, extrusion and hot drawing. The strength of ZN20 alloy wire after combined processing of FSP, extrusion and hot drawing was increased from 292 MPa to 392 MPa due to the grain boundary strengthening, precipitates strengthening and texture strengthening. It was beneficial to the ductility by promoting shear band nucleation and inhibiting its prolongation when the diameter of matrix grains and second phase particles was similar, and the ductility was increased by 3.5 times. The immersion test showed that the corrosion rate could be decreased by nearly 31% after combined processing of FSP, extrusion and hot drawing. Grain refinement could improve the corrosion resistance by stabilizing the corrosion product layer, and the smaller amount of second phase also had a positive influence on the corrosion resistance by avoiding the galvanic corrosion. [ABSTRACT FROM AUTHOR]

Mg-Zn-Ca metal glass shows good promising applications in biomaterials. MAO coating and Ca-P coating was applied on Mg69Zn27Ca4 metal glass in order to improve the alloy biodegradation resistance and biocompatibility. Microstructure observation, electrochemical experiment, immersion experiment and cell cytotoxicity experiment (MG63 cells) were carried out. The result revealed that Ca-P coating exhibited better degradation resistance than MAO coating due to its relatively thick and uniform structure. The cell cytotoxicity showed both coatings showed better bioactivity than the uncoated Mg69Zn27Ca4 metal glass. Moreover, Ca-P-coated samples had better bioactivity than those of MAO coated. Therefore, Ca-P coating improved not only the degradation resistance but also the bioactivity of Mg69Zn27Ca4 metal glass. Ca-P coating has a good promising application on Mg69Zn27Ca4 metal glass. [ABSTRACT FROM AUTHOR]

The durability and functionality of many metallic structures are seriously threatened by corrosion, which makes the development of anticorrosive coatings imperative. This state-of-the-art survey explores the recent developments in the field of anticorrosive organic coatings modulated by innovations involving nano/microcontainers with porous matrices. The integration of these cutting-edge delivery systems seeks to improve the protective properties of coatings by enabling controlled release, extended durability, targeted application of corrosion inhibitors, and can be co -constructed to achieve defect filling by polymeric materials. The major highlight of this review is an in-depth analysis of the functionalities provided by porous nano/microcontainers in the active protection and self-healing of anticorrosive coatings, including their performance evaluation. In one case, after 20 days of immersion in 0.1 M NaCl, a scratched coating containing mesoporous silica nanoparticles loaded with an inhibitor benzotriazole and shelled with polydopamine (MSNs-BTA@PDA) exhibited coating restoration indicated by a sustained corrosion resistance rise over an extended period monitored by impedance values at 0.01 Hz frequency, rising from 8.3 × 104 to 7.0 × 105 Ω cm2, a trend assigned to active protection by the release of inhibitors and self-healing capabilities. Additionally, some functions related to anti-fouling and heat preservation by nano/microcontainers are highlighted. Based on the literature survey, some desirable properties, current challenges, and prospects of anticorrosive coatings doped with nano/microcontainers have been summarized. The knowledge gained from this survey will shape future research directions and applications in a variety of industrial areas, in addition to advancing smart corrosion prevention technology. [Display omitted] • Types and fabrication techniques of porous nano/microcontainers are summarized. • Anticorrosion, self-healing, anti-fouling and heat preservation are among the functionalities provided by nano/microcontainers in coatings. • Recent developments and evaluation techniques in smart anticorrosive coating are reviewed. • A summary of desirable properties and challenges of organic coating is presented. [ABSTRACT FROM AUTHOR]

Effects of solution treatment (T4), solution and ageing treatment (T6) on the degradation behaviours, mechanical properties and cytocompatibility of the extruded Mg-1.5Zn-0.5Y-0.5Zr alloy were studied in this work. Microstructural characterisation including SEM and TEM observation, degradation behaviours, tensile experiment and cytocompatibility tests was carried out. It showed that the alloy after 500°C × 2 h and 12 h ageing treatment exhibited the best degradation resistance with the degradation rate of 0.11 ± 0.01 mm/y in Hank's solution. Moreover, the fine and uniform distributed second phases after 12 h ageing treatment could effectively improve the ultimate tensile strength (UTS) of the alloy. Due to the low degradation rate, the alloy after 500°C solution and 12 h ageing treatment also exhibited good cytocompatibility with cell viability value of more than 90%. In essence, 500°C × 2 h and 12 h ageing was the best heat treatment practice for Mg-1.5Zn-0.5Y-0.5Zr alloy. [ABSTRACT FROM AUTHOR]

The influence of external magnetic and Aharonov‐Bohm (AB) flux fields on the energy spectra and thermal properties of N2, NO, CO and H2 diatomic molecules are investigated in this study. The two‐dimensional Schrödinger equation is solved with the Varshni‐screened Coulomb potential (VSCP) model using the well‐known Nikiforov‐Uvarov (NU) method. We obtained the energy eigenvalues and wavefunctions of the system and calculated the energy levels of some diatomic molecules in the m‐arbitrary state in the presence and absence of external magnetic and AB flux fields. The results show that combining the magnetic and AB flux fields eliminates degeneracy. We analyzed and plotted the partition function and other thermal properties in the presence of a magnetic field, an AB field, and a temperature‐dependent term. [ABSTRACT FROM AUTHOR]

Friction stir processing (FSP) can play an important role in grain refinement, redistribution of second phase and texture evolution. In this study, different rotation speed was employed during FSP to process Mg-Zn-Nd (ZN20) alloy with different grain size, texture and distribution of second phase. Immersion test combined with observation on corrosion morphology was carried out to evaluate the corrosion resistance of ZN20 alloy. After FSP, grain size in the alloy could be refined to 4 μm owning to dynamic recrystallisation, the volume fraction of second phase decreased as the rotation speed increased under the influence of heat input, and strong basal texture could be formed. Finer grain size could play a positive role in improvement of the corrosion resistance by stabilising the corrosion product and acting as a barrier for corrosion cracking. Less second phase and strong basal texture cloud improve the corrosion resistance by reducing the corrosion pits. [ABSTRACT FROM AUTHOR]

The high-temperature oxidation behaviors of Nimonic95 alloy at 800 °C, 900 °C and 1000 °C were studied. The diffusion process of alloying elements in different stages of oxidation was studied and analyzed, and the pre-oxidation process was established. The results showed that multilayer oxide films formed in the air at 800 °C, 900 °C and 1000 °C, the outer layer was mainly Cr 2 O 3 with a small amount of Al 2 O 3 , TiO 2 and composite oxides such as CrTi spinel. The inner layer was mainly Al 2 O 3. Nimonic95 alloy has excellent oxidation resistance at 800 °C and 900 °C, but poor oxidation resistance at 1000 °C and the oxide film peeled off in a short time. The oxidation resistance of Nimonic95 alloy at 1000 °C can be improved significantly by pre-oxidation at 800 °C for 140 h. • The oxidation behavior of Nimonic95 alloy at 800 °C, 900 °C and 1000 °C was studied. • The diffusion mechanism of the alloy elements during different stages of oxidation was revealed. • The mechanism of improving the oxidation resistance of Nimonic95 alloy at 1000 °C by pre-oxidation process was revealed. [ABSTRACT FROM AUTHOR]

The wide application of magnesium alloys as biodegradable implant materials is limited because of their fast degradation rate. Hydroxyapatite (HA) coating can reduce the degradation rate of Mg alloys and improve the biological activity of Mg alloys, and has the ability of bone induction and bone conduction. The preparation of HA coating on the surface of degradable Mg alloys can improve the existing problems, to a certain extent. This paper reviewed different preparation methods of HA coatings on biodegradable Mg alloys, and their effects on magnesium alloys' degradation, biocompatibility, and osteogenic properties. However, no coating prepared can meet the above requirements. There was a lack of systematic research on the degradation of coating samples in vivo, and the osteogenic performance. Therefore, future research can focus on combining existing coating preparation technology and complementary advantages to develop new coating preparation techniques, to obtain more balanced coatings. Second, further study on the metabolic mechanism of HA-coated Mg alloys in vivo can help to predict its degradation behavior, and finally achieve controllable degradation, and further promote the study of the osteogenic effect of HA-coated Mg alloys in vivo. [ABSTRACT FROM AUTHOR]

Currently, orthopaedic implant materials such as titanium alloy are biologically inert materials which are not easily integrated with bone tissues, thus resulting in implantation failures due to the loosening and infection. In this study, bioactive MgXCu(X = 0, 0.1, 0.4, 0.7) coatings were successfully fabricated on Ti6Al4 V substrate by arc ion plating (AIP) technique to improve the antibacterial property. The surface composition and morphology of the coating was characterised by X-ray diffraction, inductively coupled plasma-atomic emission spectrometry (ICP) and scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). The electrochemical experiment and immersion test showed the corrosion rate of MgXCu coating increased with the addition of Cu element. Antibacterial assays proved that the MgXCu coating could successfully reduce the viability of Staphylococcus aureus (S.aureus) and the thickness of the bacterial film. Consequently, it is concluded that MgXCu coated Ti6Al4 V with antibacterial property is much potential to be used in orthopaedic applications. [ABSTRACT FROM AUTHOR]

• Cu was introduced into the micro-arc oxidation coating successfully. • Cu enhanced the corrosion resistance of the MAO coating. • Cu + MAO coating could effectively inhibit the bacterial proliferation. Copper (Cu) has a good antibacterial effect and micro-arc oxidation (MAO) coating has good corrosion resistance for magnesium (Mg) alloys. If they are combined together, the coated Mg alloy is expected to have both good corrosion resistance and antibacterial effect. In this work, the degradation, antibacterial property and cytotoxicity of a Cu-containing MAO coating on an extruded Mg-2Zn-1Gd-0.5Zr alloy were systematically studied. The results revealed that the addition of Cu could further improve the degradation resistance of MAO coated alloy. After two weeks immersion, the corrosion rate of Cu + MAO coated alloy was 0.16 mm/y, lower than those of both MAO coated and uncoated alloy. The release of Cu2+ from Cu + MAO coated alloy inhibited the bacterial proliferation. After 12 h co-culture, the antibacterial rate reached 96%. Cytotoxicity test (MG63 cell) showed that Cu + MAO coated alloy had good biocompatibility. The Cu + MAO coating has great potential for application on Mg alloys due to its good corrosion resistance, antibacterial property and good biocompatibility. [ABSTRACT FROM AUTHOR]

Abstract Coating is one of the effective methods to improve the corrosion resistance of the biodegradable Mg alloys. In this work, comparative study on the effects of micro-arc oxidation (MAO) coating, Sr P coating and Ca P coating on the biodegradable and wear properties of Mg-2Zn-1Gd-0.5Zr alloy were investigated. The results showed that the degradation deposition contained Gd on the surfaces of both MAO coating and Sr P coating, which stabilized the coating, thereby increasing the degradation resistance of the alloy. The wear test showed that MAO coating and Ca P coating exhibited good wear resistance. For a 5 N loading, the sliding distances of MAO coating, Sr P coating and Ca P coating were 2.24 m, 0.29 m and 9.00 m respectively, before the coatings were completely destroyed. This investigation revealed that the MAO coating exhibits the best degradation resistance and the Ca P coating exhibits the best wear resistance. Highlights • (1) The degradation products contained Gd could increase the degradation resistance of the MAO and Sr P coated alloys. • Gd 2 O 3 in MAO coating could stabilize the coating and delay the degradation process. • The rod-like deposition could act as a barrier to improve the wear resistance of the Ca P coated alloy. [ABSTRACT FROM AUTHOR]

Rare earth-containing biodegradable magnesium alloys have attracted many researchers attention due to their good mechanical property and degradation resistance. In this paper, comparative study of the effect of Nd and Y content on the mechanical and biodegradable properties of Mg-2Zn-0.5Zr-xRE alloys was carried out. The results showed that there are mainly α-Mg, Mg12Nd, T-phase ((MgZn)92Nd8) and MgZn2 phase in Mg-2Zn-xNd-0.5Zr alloys. There were mainly α-Mg, I-phase, W-phase and MgZn2 phase in Mg-2Zn-xY-0.5Zr alloys. Minor addition of Nd could both improve the elongation (> 20%) of the alloys and decrease the galvanic corrosion between the matrix and the second phases. However, the addition of Y (1%) was beneficial in improving the ultimate tensile strength (UTS) of the Mg alloys. Minor addition of Y (0.5%) could also improve the degradation resistance of the alloys. The alloys with 0.5% Nd and 0.5% Y have great potential to be used as biomaterials. [ABSTRACT FROM AUTHOR]

Biodegradable Mg-Cu alloys have attracted many researchers attention due to their characteristics of osteogenesis, angiogenesis, and long-lasting antibacterial effects. In this paper, the effect of copper content on the corrosion behaviors and antibacterial properties of binary Mg-Cu alloys was studied. Microstructure characterization, immersion test, electrochemical test and antibacterial test were carried out. The results show that with the increase of Cu content, the corrosion rate of Mg-Cu alloys was increased greatly due to the galvanic corrosion between Mg matrix and Mg2Cu intermetallic phase. The corrosion rate of Mg-0·3Cu alloy was almost 10 times as fast as Mg-0·1Cu alloy in 0·9 wt-% NaCl solution. Antibacterial test showed that Mg-Cu alloys could efficiently reduce the viability of Candida albicans with the addition of Cu above 0·1 wt-%. Mg-0·1Cu has good potential to be used as antibacterial implants due to its good corrosion resistance and antibacterial property. [ABSTRACT FROM AUTHOR]