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Paper aims to an alloy development study was carried out to increase the mechanical properties of cylinder heads.

AlSi12 alloys are used to manufacture the compressor head cylinder by high-pressure casting for easy casting and superior properties. Therefore, 1.1%, 2.4% and 3.1% Mg were added to AlSi12. The microstructures of the produced samples were characterized by optical microscope, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction methods. Hardness and tensile tests as well as Charpy impact tests were performed. Wear tests were also carried out on the pin-on disc tester, and then the wear performance was examined on the tester, which simulates the actual operating condition.

AlSi12 has primary Si and eutectic Si in the Al matrix. However, alloys of Mg with AlSi12 have other intermetallics such as Mg₂Si and ß-Fe, as well as primary Si and eutectic Si. Hardness and tensile strength as well as improved wear performance with increased Mg content.

In this study, wear performance test to simulate the operation of the cylinder head produced by high pressure casting from AlSi12 alloy moreover tensile test, hardness test and impact test were performed. Therefore, in this study, the wear performance of the compressor head produced by high-pressure casting method by adding three different amounts of Mg to AlSi12 alloy was investigated.

This study aims to investigate the effect of microalloyed Ca and Ce on microstructure and corrosion behavior of Mg-1.5Zn alloy. Mg-1.5Zn-xCa-xCe alloys were prepared by melting, extrusion and rolling processes.

The effects of adding Ca and Ce elements alone or adding Ca and Ce elements simultaneously on the microstructure and corrosion resistance of Mg-1.5Zn-xCa-xCe (x = 0 or 0.2 Wt.%) alloys were studied by scanning electron microscopy, hydrogen evolution tests and electrochemical experiments.

The addition of Ca and Ce elements alone or the addition of Ca and Ce elements had little impact on the grain size of the rolled and annealed Mg-1.5Zn-xCa-xCe alloy, but had a greater effect on the type and quantity of the second phase.

The order of the corrosion rates for the three alloys was Mg-1.5Zn-0.2Ca < Mg-1.5Zn-0.2Ca-0.2Ce < Mg-1.5Zn-0.2Ce. Mg-1.5Zn-0.2Ca showed the best corrosion resistance, which was related to the second phase and corrosion products.

The influence of Zn concentration on microstructure and corrosion performance of the Mg–xZn alloys microalloyed with Ca and Ce was investigated through optic microscopy, scanning electron microscopy, hydrogen evolution, dynamic polarization and electrochemical impedance spectroscopy experiments.

In this paper, Mg–xZn alloys (x = 0.5∼2.0 Wt.%) microalloyed with Ca and Ce (0.2 Wt.% each) were prepared.

As the increase of Zn concentration, the number of second phase particles (Mg-Zn-Ca, Mg-Zn-Ce and Mg-Ce phases) increased, and when the Zn concentration increased to 2.0 Wt.%, the new second phase Mg-Zn phase was precipitated.

The influence of Zn concentration on corrosion mechanism of Mg-xZn alloys microalloyed with Ca and Ce was revealed. Increasing of the Zn concentration resulted in the intensification of galvanic corrosion. When Zn concentration was 0.5 Wt.%, the alloy showed the lowest corrosion rate (0.61 mm y-1), which was about 1/2 of that of Mg-2.0Zn-0.2Ca-0.2Ce alloy.

This paper aims to investigate the effect of aluminum addition on the microstructure and mechanical properties of Mg-8Gd-4Y-1Zn alloy.

Mg-8Gd-4Y-1Zn-xAl (x = 0, 0.5, 1.0, 1.5, 2.0 Wt.%) alloys were prepared by the conventional gravity casting technology, and then microstructures, phase composition and mechanical properties were investigated by material characterization method, systematically.

Results show that the as-cast microstructure of Mg-8Gd-4Y-1Zn alloy mainly consists of a-Mg matrix as well as Mg₁₂REZn (18 R LPSO structure), and island-like Mg₃(RE, Zn) phase is distributed at the grain boundary. The addition of a small amount of Al (0.5 Wt.%) can decrease the content of island-like Mg₃(RE, Zn) phase, but significantly increase the content of long-period stacking ordered (LPSO) structure, resulting in the improvement of both tensile strength and elongation of Mg-8Gd-4Y-1Zn alloy. However, the addition of excessive Al will consume Re element and decrease the amount of LPSO structure, leading to the decrease of tensile properties. When the content of Al is 0.5 Wt.%, the tensile strength and elongation are 225 MPa and 9.0% of Mg-8Gd-4Y-1Zn alloy, which are 14% and 29% higher than that of Mg-8Gd-4Y-1Zn alloy, respectively.

Adding aluminum to Mg-8Gd-4Y-1Zn alloy strengthens its mechanical properties. And the effect of Al content on the alloy strengthening. The formation mechanism of LPSO structure with different aluminum content was revealed.

This paper aims to figure out the conundrum that the corrosion resistance longevity of steel wires for bridge cables was arduous to meet the requirements.

The “two-step” hot-dip coating process for cable steel wires was developed, which involved first hot-dip galvanizing and then hot-dip galvanizing of aluminum magnesium alloy. The corrosion rate, polarization curve and impedance of Zn–6Al–1Mg and Zn–10Al–3Mg alloy-coated steel wires were compared through acetate spray test and electrochemical test, and the corrosion mechanism of Zn–Al–Mg alloy-coated steel wires was revealed.

The corrosion resistance of Zn–10Al–3Mg alloy-coated steel wires had the best corrosion resistance, which was more than seven times that of pure zinc-coated steel wires. The corrosion current of Zn–10Al–3Mg alloy-coated steel wires was lower than that of Zn–6Al–1Mg alloy-coated steel wires, whereas the capacitive arc and impedance value of the former were higher than that of the latter, making it clear that the corrosion resistance of Zn–10Al–3Mg was better than that of Zn–6Al–1Mg alloy coating. Moreover, the Zn–Al–Mg alloy-coated steel wires for bridge cables had the function of coating “self-repairing.”

Controlling the temperature and time of the hot dip galvanizing stage can reduce the thickness of transition layer and solve the problem of easy cracking of the transition layer in the Zn–Al–Mg alloy coating due to the Sandelin effect.

The purpose of this paper is to design and develop precipitation hardened Al-Mg alloy imparting enhanced strength with acceptable ductility through minor addition of Sc and Cr by using multi-objective genetic algorithm-based searching. In earlier attempts of strengthening aluminum alloys, owing to the formation of Al₃Sc and Al₇Cr phase, addition of Sc and Cr have yielded attractive precipitation hardening, respectively. Both the Al-Sc and Al-Cr system are quench sensitive due to presence of a sloping solvus in their phase diagrams. It is also known that both the Al₃Sc and Al₇Cr phases nucleate directly from the supersaturated solid solution without formation of GP-zones or transient phases prior to the formation of the Al₃Sc and Al₇Cr. Sc also found to have beneficial effect on the corrosion property of such alloys. In view of the above, it is of interest to explore the possibility of enhancing the age hardening effect in Al-Mg alloy by addition of Sc and Cr.

The paper uses an approach where experimental information of two different alloy systems (namely, Al-Mg-Sc and Al-Cr) has been combined to generate a single database involving the potential features of both the systems with the aim to formulate the suitable artificial neural network (ANN) models for strength and ductility. The models are used as the objective functions for the optimization process. The patterns of the optimized Pareto front are analyzed to recognize the optimal property of the alloy system. The hitherto unexplored Al-Mg-Sc-Cr alloy, designed from the Pareto solutions and suitably modified on the basis of prior knowledge of the system, is then synthesized and characterized.

The paper has demonstrated the ANN- and genetic algorithm (GA)-based design of a hitherto unexplored alloy by utilizing the existing information concerning the component alloy systems. The paper also established that analyses of the Pareto solutions generated through multi-objective optimization using GA provide an insight of the variation of the parameters at different combination of strength and ductility. It also revealed that the Al-Mg-Sc-Cr alloy has exhibited a two-stage age hardening effect. The first and second stages are due to the precipitation of Al₃Sc and Al₇Cr phases, respectively.

In the present study the two alloy systems are used in tandem to develop models to describe the properties involving the distinct mechanistic features of phase evolution inherent in both the systems. Though the ANN models having the capability to capture huge non-linearity of a system have been employed to predict the convoluted effects of those characteristics when an alloy containing Mg, Sc and Cr are added simultaneously, but the ANN models predictions can be checked experimentally by the future researchers.

The paper demonstrates the role of scandium and chromium addition on the ageing characteristics of the alloy by analyzing the age hardening behavior of the designed alloy in cast and cold rolled condition clearly.

The approach stated in this paper is a novel one, in the sense that experimental data of two different alloy systems have been clubbed to generate a single database with the aim to formulate the suitable ANN models for strength and ductility.

This paper aims to investigate microstructure, corrosion behavior and mechanical properties of Mg-4Li and Mg-4Li-3Al.

The microstructure was characterized by using scanning electron microscopy and electron backscatter diffraction. The corrosion behaviors were measured by hydrogen evolution and potentiodynamic polarization tests. The mechanical properties were evaluated by tensile tests.

The addition of Al results in the precipitation of some Mg-Al phase and Al3Li phase particles, and the formation of some fine recrystallized grains.

Mg-4Li-3Al showed a higher corrosion rate than that of Mg-4Li, attributed to the precipitate particles in Mg-4Li-3Al causing microgalvanic corrosion and the change of grain orientation. The addition of 3 Wt. per cent Al increased the tensile strength by solid solution strengthening, precipitation strengthening, refinement strengthening and texture strengthening, whilst the elongation decreased by almost half.

The purpose of this investigation was to synthesize a doped polyaniline‐containing coating and investigate the anti‐corrosion properties of the coating on Mg‐Li alloy.

The doped polyaniline pigments were prepared by two different methods using ammonium persulphate as oxidant and hydrochloric acid, phosphoric acid, p‐toluene sulfonic acid and sulfosalicylic acid as doping agents. The doped polyaniline was characterized by Fourier transform infrared (FT‐IR) analysis, X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The coatings consisted of polyaniline, epoxy resin and other additives that were formed on Mg‐Li alloy. The anti‐corrosion properties of the polyaniline‐containing coating on the Mg‐Li alloy were investigated in 3.5 wt.% NaCl solution using open circuit potential logging and electrochemical impedance spectroscopy.

The results of the electrochemical tests indicated that the polyaniline‐containing coatings showed better anti‐corrosion properties, as compared to conventional epoxy coatings on Mg‐Li alloy when exposed in 3.5 wt.% NaCl solution. The coating containing 2 wt.% polyaniline (relative to the mass of epoxy resin) doped with hydrochloric acid had the best anti‐corrosion properties on the Mg‐Li alloy.

Previous reports on the anti‐corrosion properties of polyaniline‐containing coatings focused mainly on the surface of iron, steel, aluminum and magnesium, and there have been few studies on the anti‐corrosion properties as protective coatings for Mg‐Li alloy.

MAGNESIUM, because of its low density, has obvious possibilities as an aircraft structural material. The useful magnesium alloys have densities in the range 1·76 to 1·83, compared with the aluminium alloys range of about 2·5 to 2·8. The melting point of magnesium is 650 deg. C., almost identical with that of aluminium (660 deg. C.), so that generally the alloys of each of these base elements have applications in much the same temperature band.

Porous implant surface is shown to facilitate bone in-growth and cell attachment, improving overall osteointegration, while providing adequate mechanical integrity. Recently, biodegradable material possessing such superior properties has been the focus with an aim of revolutionizing implant’s design, material and performance. This paper aims to present a comprehensive investigation into the design and development of low elastic modulus porous biodegradable Mg-3Si-5HA composite by mechanical alloying and spark plasma sintering (MA-SPS) technique.

This paper presents a comprehensive investigation into the design and development of low elastic modulus porous biodegradable Mg-3Si-5HA composite by MA-SPS technique. As the key alloying elements, HA powders with an appropriate proportion weight 5 and 10 are mixed with the base elemental magnesium (Mg) particles to form the composites of potentially variable porosity and mechanical property. The aim is to investigate the performance of the synthesized composites of Mg-3Si together with HA in terms of mechanical integrity hardness and Young’s moduli corrosion resistance and in-vitro bioactivity.

Mechanical and surface characterization results indicate that alloying of Si leads to the formation of fine Mg2 Si eutectic dense structure, hence increasing hardness while reducing the ductility of the composite. On the other hand, the allying of HA in Mg-3Si matrix leads to the formation of structural porosity (5-13 per cent), thus resulting in low Young’s moduli. It is hypothesized that biocompatible phases formed within the composite enhanced the corrosion performance and bio-mechanical integrity of the composite. The degradation rate of Mg-3Si composite was reduced from 2.05 mm/year to 1.19 mm/year by the alloying of HA elements. Moreover, the fabricated composites showed an excellent bioactivity and offered a channel/interface to MG-63 cells for attachment, proliferation and differentiation.

Overall, the findings suggest that the Mg-3Si-HA composite fabricated by MA and plasma sintering may be considered as a potential biodegradable material for orthopedic application.