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This research mainly focuses on selecting phase change materials (PCM) and container materials for next-generation concentrated solar power plants (CSP). The present study investigates the hot corrosion behaviour of Inconel 617 and 625 in Na2SO4 + 45 wt-% diatomite PCM environment at 800°C for 40, 80 and 120 h. Oxide scales developed on the alloy surfaces were examined by Scanning electron microscope (SEM) and X-ray diffraction (XRD) to study morphology and oxide phases. The result indicates that Inconel 617 and 625 weight changes were 1.239 and 0.925 mg cm−2 at 800°C for a maximum duration of 120 h. The dense oxide of Cr2O3 is formed on alloys 617 and 625, which gives better oxidation resistance in a PCM environment. Moreover, the Inconel 625 shows lesser weight gain compared to Inconel 617 due to the presence of higher wt-% of Cr in the alloy and Nb formation oxides reducing corrosion species diffusion rate. [ABSTRACT FROM AUTHOR]

The study of laser cladding of 90Ti-10Al2O3, 90Ti-8Al2O3-2Zn and 90Ti-4Al2O3-6Zn coatings onto Ti-6Al-4V alloy, with intention to produce defect-less, high microhardness and wear resistant coating was carried out. The coatings were deposited onto Ti-6Al-4V alloy at 900 W laser power and 0.6 m/min laser scan speed. Microstructures and phase constituents of the developed coatings were investigated by using a scanning electron microscope (SEM) and X-ray diffractometer correspondingly. Vickers microhardness tester and pin-on-disk tribometer were employed to characterize microhardness and wear behaviour of the Ti-Al2O3/Zn coatings respectively. SEM was also used to examine the worn track. It was observed that 90Ti-10Al2O3 coating yielded optimal microhardness along with maximal wear resistance in comparison to the other coatings and Ti-6Al-4V alloy. It has been established that laser cladding of Ti-Al2O3 coating with Zn contents on Ti-6Al-4V alloy alleviates the formation of cracks, however, microhardness and wear properties are negatively affected. [ABSTRACT FROM AUTHOR]

The AlFeCoNiCrTi high-entropy alloy (HEA) powders were prepared by high-energy ball milling. The ultrafine-grained WC–HEA and WC–Co-cemented carbides were fabricated through planetary ball milling and heat-pressure sintering. The microstructures and properties of the sintered alloys were compared using scanning electron microscope, X-ray diffraction, mechanical property testing and electrochemical testing. It has been shown that the AlFeCoNiCrTi HEA can be used as a binder for the ultrafine-grained WC-based cemented carbide. The WC–HEA-cemented carbide has better performances than the WC–Co-cemented carbide. The suitable contents of HEA can inhibit the WC grain growth and improve the mechanical properties and corrosion resistance of cemented carbides. [ABSTRACT FROM PUBLISHER]

In the present work, time of calcium phosphate formation on Ti6Al4V alloy with or without alkali and heat treatments was investigated. Specimens were soaked in 0, 5 and 10M solutions of NaOH at temperatures of 60 and 80°C for 1 and 3 days and then their surfaces were characterised by using scanning electron microscopy and thin film X-ray diffraction. It was found that optimum condition is 3 days soaking in 5M NaOH in 80°C. Specimens treated under these optimum conditions were subsequently heat treated at 500, 600 and 700°C for 1 h to consolidate the sodium titanate hydrogel layer. With heat treatment at 600°C for 1 h and then soaking in simulated body fluid, apatite formed within 3 days. However, there were no signs of apatite formation in control samples (without alkali and heat treatment) up to 7 days soaking in SBF. [ABSTRACT FROM AUTHOR]

In this study, the Ti-6Al-4V alloy was diffusion bonded to austenitic stainless steel at temperatures of 820, 885, 930 and 980°C, under a pressure of 5 MPa for 30 min. The effect of temperature on interface formations and microstructure was investigated using a scanning electron microscope (SEM), energy dispersive spectrograph (EDS) microanalyses, X-ray diffraction and shear strength of bonded specimens. The results showed that intermetallic phases and a-phase formed in the interface region. [ABSTRACT FROM AUTHOR]

A method of accurate serial sectioning has been designed for three-dimensional texture measurement in aluminium alloy sheet. Using this method, determination of three dimensional texture in an AA6111-T4P sheet has been carried out by electron backscatter diffraction (EBSD) in a scanning electron microscope (SEM) from the sheet surface to 1/3 of the thickness. Optimal conditions for specimen preparation and SEM operation have been investigated to ensure minimum planar displacement or rotation among sections. It has been demonstrated that in the AA6111-T4P sheet the {001}<100> (cube), {011}<100> (Goss) and {011}<455> (P*) orientations are the major texture components. The through thickness averaged cube and Goss components are aligned parallel to the rolling direction forming a banded structure, and the bands of the cube and Goss are distributed alternately in the transverse direction. The variation in grain size is very limited compared with the texture components. [ABSTRACT FROM AUTHOR]