Corrosion behaviour induced by crystal structure transformation of Mg alloy with AlTiB

The superlight Mg–Li alloys exhibit good formability but poor corrosion resistance due to the alloying of lithium. In this paper, the corrosion behaviour of Mg–8·8Li alloy was investigated by electrochemical measurements, corrosion morphology observations and weight loss determination. The results indicate that Mg–8·8Li alloy displays worse corrosion resistance than AZ91D alloy in the early stages of corrosion. However, the corrosion resistance of AZ91D alloy declines and becomes worse than Mg–8·8Li alloy with increasing exposure time. In addition, it is found that a 250°C annealing treatment has a detrimental effect on the corrosion resistance of Mg–8·8Li alloy.

Corrosion behavior and surface treatment of superlight Mg–Li alloys

Biodegradable Zn–Mn–Li alloy with a promising balance of mechanical property and corrosion resistance

Effects of Li addition on the properties of biodegradable Zn–Fe–Li alloy: Microstructure, mechanical properties, corrosion behavior, and cytocompatibility

Microstructural improvement of Al-Cu-Li alloys with high Li content plays a critical role for the acquisition of excellent mechanical properties and ultra-low density. In this regard, the Al-Cu-Li alloy castings with high Li content from 1.5wt.% to 4.5wt.% were prepared by near-rapid solidification, followed by two-stage homogenization treatment (490 °C/16 h and 530 °C/16 h). The microstructural evolution and solidification behavior of the as-cast and homogenized alloys with different Li contents were systematically studied by combining experiments with calculations by Pandat software. The results indicate that with the increase of Li content, the grain sizes decrease, the solution ability of Cu in the matrix α-Al phase increases, while the content of secondary dendrites increases and the precipitated phases change from low melting point phases to high melting point phases under the near-rapid solidification. Additionally, by the coupling of near-rapid solidification and two-stage homogenization, the metastable precipitated phases (Al7Cu4Li and AlCu3) can be dissolved effectively in the alloys with Li content of 1.5wt.%–2.5wt.%; moreover, the stable precipitated phases (Al6CuLi3 and Al2CuLi) uniformly distribute at the grain boundaries in the alloys with Li content of 3.5wt.%–4.5wt.%. As a result, the refined and homogenized microstructure can be obtained.

The process of electroplating with Cu on the surface of Mg–Li alloy

Nickel aluminum bronze alloy, a complex alloy containing multiple phases, has become the most common material for naval propellers due to its good corrosion resistance. Traditional cast nickel aluminum bronze shows serious corrosion behavior in harsh service environments. This article reviews progress on the corrosion behaviors and corrosion mechanism of nickel aluminum bronze in highly corrosive and complex marine environments and systematically discusses the research status of the surface modification technologies such as laser surface strengthening, mechanical shot peening, friction stir and thermal spraying, and so on. To improve the comprehensive performance of nickel aluminum bronze, this work focuses on analyzing the effect of process parameters on the corrosion resistance of nickel aluminum bronze alloy while researching propeller blade surface modification technology. Finally, the future research and development direction of nickel aluminum bronze in the fields of laser and arc additive manufacturing is prospected.

Selective laser melting (SLM) is an ideal method to directly fabricate products with high geometrical complexity. With low density and good corrosion resistance, aluminum alloys are widely used as important structural materials. Microstructures and mechanical properties of SLMed aluminum alloys have been recently widely studied. Corrosion behavior as a vital concern during the service of SLMed aluminum alloy parts has also drawn many attentions. Previous studies have found that SLM-processed aluminum alloys exhibit better corrosion resistance compared to the casted and wrought counterparts for both Al-Si alloys and high strength 2xxx Al alloys, which is mainly due to the unique microstructure features of SLMed Al alloys. For Al-Si alloys, with different shapes of Si networks, the different building planes show discrepant corrosion behaviors. Owing to the rougher surface with relatively larger numbers of defects, the as-printed surface is vulnerable to corrosion than the polished. Heat treatment has a negative effect on corrosion resistance due to the breakup of Si networks. The microstructure features correlated with the corrosion behaviors were also reviewed in this paper. Some suggestions on the future study of corrosion behaviors of SLMed Al alloys were put forward.

An attempt has been made in the present investigation to weld high nitrogen steel of 5mm thick plates using various process i.e., shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW) and autogenous electron beam welding (EBW) process. Present work is aimed at studying the microstructural changes and its effects on mechanical properties and corrosion resistance. Microstructure is characterized by optical, scanning electron microscopy and electron back scattered diffraction technique. Vickers hardness, tensile properties, impact toughness and face bend ductility testing of the welds was carried out. Pitting corrosion resistance of welds was determined using potentio-dynamic polarization testing in 3.5%NaCl solution. Results of the present investigation established that SMA welds made using Cr-Mn-N electrode were observed to have a austenite dendritic grain structure in the weld metal and is having poor mechanical properties but good corrosion resistance. GTA welds made using 18Ni (MDN 250) filler wire were observed to have a reverted austenite in martensite matrix of the weld metal and formation of unmixed zone at the fusion boundary which resulted in better mechanical properties and poor corrosion resistance. Fine grains and uniform distribution of delta ferrite in the austenite matrix and narrow width of weld zone are observed in autogeneous electron beam welds. A good combination of mechanical properties and corrosion resistance was achieved for electron beam welds of high nitrogen steel when compared to SMA and GTA welds.

Microstructural aspects of additive manufacturing of Al[sbnd]Li alloys with high Li content

The Mg–Li alloys with Li content of 5–11 mass-% will exhibit a dual phase structure of α (hcp) and β (bcc) phases. These dual phase Mg–Li alloys have excellent formability, as well as extra low density. However, the Mg–Li alloys still have disadvantages of poor corrosion and wear resistance. In the present study, the AlN films deposited on Mg–Li alloy by radio frequency magnetron sputtering were investigated. The microstructure, surface morphology and corrosion resistance of the AlN films were examined by means of X-ray diffraction, SEM, TEM, and potentiodynamic polarisation. Experimental results show that deposited AlN films exhibit an amorphous structure, which can effectively improve the corrosion resistance of Mg–Li alloy. Meanwhile, the sputtering parameters, such as the radiofrequency power and working pressure, are found to have significant effects on the corrosion behaviour of deposited AlN films on Mg–Li alloy.

Lithium isotope fractionation during incongruent melting: Constraints from post-collisional leucogranite and residual enclaves from Bengbu Uplift, China

Influence alloying elements of Al and Y in Mg Li alloy on the corrosion behavior and wear resistance of microarc oxidation coatings

Insight into role and mechanism of Li on the key aspects of biodegradable ZnLi alloys: Microstructure evolution, mechanical properties, corrosion behavior and cytotoxicity.

Corrosive behavior and interfacial conductivity of stampable a-C film on titanium bipolar plate in proton exchange membrane fuel cells