Performance Of Magnesium Alloy Research Articles

First-principles study of binary and ternary phases in Mg-Gd-Ni alloys

Given the high demand for magnesium alloys across industries, it's crucial to enhance their performance by developing alloys with superior characteristics. The performance of magnesium alloys is closely related to the properties of the precipitated phase. However, there has been insufficient exploration of the mechanical properties of precipitated phases in Mg-Gd-Ni alloys. Hence, this paper calculates the formation energy, electronic structure, elastic modulus, and elastic anisotropy of the precipitated phase in Mg-Gd-Ni alloys using first principles. Calculations of formation energies and elastic constants demonstrate that MgGdNi4, Mg2Ni, 18R-LPSO, Mg2Gd, and 14H-LPSO possess commendable thermodynamic and mechanical stability. Elastic modulus calculations reveal a significant increase in the elastic modulus of magnesium, especially the bulk modulus, upon the addition of Gd and Ni elements, increasing from 34.5 GPa to a peak of 84.9 GPa. Furthermore, the strength increments of the corresponding precipitated alloys, calculated based on the elastic modulus, underscore MgGdNi4 as exhibiting the most significant strength increment. The elastic anisotropy of each second phase is evaluated using the elastic anisotropy factor, the three-dimensional surface, and the projection onto each two-dimensional plane. The order of elastic modulus anisotropy for shear and Young's modulus is MgGdNi4 > Mg2Ni > 18R-LPSO > Mg2Gd > 14H-LPSO. This study provides valuable data for regulating properties in magnesium alloys.

The effect of texture on the very high cycle fatigue performance and deformation mechanism of rolled AZ31B magnesium alloys

AbstractRolling can result in anisotropy in the microstructure and mechanical properties of the sheet material. This study focuses on the very high cycle fatigue (VHCF) performance of magnesium alloys in the rolling direction (RD), normal direction (ND), and the bisecting angle between the ND and RD (ND–RD). The findings reveal that RD specimens demonstrate superior fatigue performance, while the ND specimens exhibit the lowest fatigue resistance. During the crack initiation stage, the primary influential factor is the maximum shear stress. Due to c‐axis alignment with ND direction in grains, the deformation mode for ND and RD specimens primarily involves first‐order pyramidal slip, while ND–RD specimens primarily undergo basal slip and prismatic slip. In early stable crack propagation, grain size and texture cause variations in the morphology of the rough area among the three directional specimens. Notably, the RD specimens show faster crack propagation during crack initiation than early stable propagation stage.

Influence of Processing Temperature and Strain Rate on the Microstructure and Mechanical Properties of Magnesium Alloys Processed by Single-Pass Differential Speed Rolling

Magnesium-based alloys show significant promise for widespread applications owing to their lightweight nature and improved mechanical properties achieved through grain refinement via hot rolling. This investigation focuses on Mg-xAl-yCa-zMn (AXM alloys), pre-heated to temperatures of 350, 400, and 450 °C and processed via both single-pass differential speed rolling (DSR) and conventional rolling (CR). The key findings reveal the interplay between processing temperature, strain rate during single-pass rolling, and an innovative approach for incorporating varying amounts of Ca, influencing grain size, quantity of dynamic recrystallization (DRX) grains, and overall mechanical properties, including strength and ductility. A noteworthy observation is the positive correlation between an increase in the total reduction during hot rolling and a higher fraction of DRXed grains. This leads to a significant reduction in average grain size, diminishing from 60.3 ± 54.3 μm to 19.5 ± 14.2 μm at 40%, nearly a third the size of T4 grains (the initial homogenized microstructure of the AXM alloys). The resultant material strength experiences a doubling from an average of 125 ± 10.2 MPa (T4) to 260 ± 25.8 MPa (DSR rolled at 40%) for the AXM alloys with potential improvement in the ductility depending on rolling speed conditions. This study also aims to analyze the combination of rolling temperature, rolling speed, thickness reduction, speed difference and Ca content implemented across a wide range of temperatures and strain rates to provide a holistic approach to the processing parameters affecting the microstructure and mechanical properties of AXM alloys. Furthermore, this study provides a deeper understanding of DRX mechanisms, including continuous DRX (CDRX), discontinuous DRX (DDRX), and twinning induced DRX (TDRX), while each of these mechanisms plays a distinct role in the overall enhancement of formability and performance of magnesium alloys.

Influence of Heat Treatment on the Weld Structure and Performance of Magnesium Alloy

To know the influence of heat treatment on the weld structure and performance of magnesium alloy. Use TIG weld method to research the performance variation of AZ31B magnesium alloy at different temperatures.The performance of AZ31B magnesium alloy at 300? and 400? improves; the performance of AZ31B magnesium alloy at 450? declines. The welding at 450? goes against improvement of the performance of AZ31B magnesium alloy, which indicates that temperature 450? shall not be used in actual heat treatment on AZ31B magnesium alloy.

Preparation and Performance of Electroless Nickel on AZ91D Magnesium Alloy

The corrosion of magnesium alloy in different plating solutions was researched. The results demonstrated that corrosive condition of the alloy immersed in nickel chloride solution and nickel sulfate solution is serious and in nickel acetate solution and nickel nitrate solution is less. Magnesium alloy was handled with four acid pickling formulas and two activation formulas and the effects of different pickling formulas and activation formulas were researched through comparative experiment. The experimental results indicated that after handed with pickling formula about 500 mL L−1 H3PO4 (85%), 110 mL L−1 HNO3 (68%), room temperature for 30 s and activation formula about 375 mL L−1 HF (40%), room temperature for 10 min, magnesium alloy could realize electroless nickel plating directly and the performance of the prepared plating was much better. The properties of the nickel-plating coating were researched by electrochemical workstation, scanning electron microscope, and X-ray diffraction. The results demonstrated that this Ni–P coating was very uniform and meticulous; the structure of Ni–P coating was amorphous; and comparing with magnesium alloy, the corrosion potential of this plating increased about 799 V and the corrosion current density declined obviously. The nickel-plating coating effectively improved the anticorrosion performance of magnesium alloy.

Mixing Y89 Influence on Mechanical Properties of Casting Mg17Al12

For its light quality, good thermal conductivity, and excellent electricity shielding performance, Magnesium alloy has been used in industry, agricultural and so on, for rare earth elements can improve the mechanical performance of magnesium alloy, the study of powder metallurgy is influence by rare earth magnesium is few at present. so, in this paper, by mixing powder metallurgy method the Y89 element was added in Mg17Al12 magnesium alloy, the influence of Y89 on microstructure, hardness and compression performance of Mg17Al12 magnesium alloy was studied, The experimental results show that when amount of Y89’s addition, the mechanical performance is more then and when is 1.22%, its mechanical performance is best, hardness is 66.7 HV, compressive strength is 113.6 MPa,increased respectively by 19.7% and 29.3% compared the Mg17Al12 magnesium alloy substrate, and the grain refinement effect of Mg17Al12 magnesium alloy is the best at this time.

Role of Surface Reactivity in Processing and Performance of Magnesium Alloys

The surface reactivity of magnesium alloys at high temperatures required for their processing in solid, semisolid and liquid states is reviewed emphasizing presently existing barriers of its understanding and control. In addition to general aspects of magnesium oxidation, other forms of reactivity such as ignition and flammability are discussed. Since surface oxide, composed of pure MgO, does not offer a sufficient protection, operations of raw alloy melting and component manufacturing require protective atmospheres what has detrimental implications on process economy and product performance. Efforts to develop ignition resistant magnesium alloys through modification of their chemistry are described with a particular role of rare earths and other elements with high affinity to oxygen. It is concluded that all forms of magnesium reactivity in solid and liquid state could be explained through diffusion characteristics of surface oxide formed during processing and service.

Two- and three- dimensional studies of dendritic morphology in magnesium alloy by means of synchrotron X-ray microtomography and cellular automaton modelling

Magnesium is the lightest structural material. As one of the dominant microstructure features, dendritic pattern determines the mechanical behaviour and performance of magnesium alloys. Dendritic topological observation was carried out on Mg-based alloy using synchrotron X-ray micro-tomography and the microstructure pattern of α-Mg dendrite was obtained. It was found that the α-Mg dendrite grew with eighteen primary stems, of which six lay in the (0001) basal plane, and the other twelve in the (1010) plane. An according numerical model based on the cellular automata method was developed. By defining a specific capturing functional mechanism, simulation of α-Mg dendrite in 3-D with eighteen branches was successfully achieved. The simulation results show that the model could reasonably describe the evolution of the dendritic microstructure and the subsequent dendrite morphology agrees well with that observed in the synchrotron X-ray tomography experiment.

Experimental research on degradation performance of magnesium alloy affected by mechanical environment

Objective To research the mechanical properties of magnesium alloy degradation affected by mechanical environment. Methods: After being divided into 4 groups randomly such as No.1, 2, 3 and 4,12 AZ31 magnesium alloy screws need suspending in the vessels containing 35ml simulated body fluid. No.1 was control group. Group 1 was under no load condition, experimental group 2, 3, and 4 were discontinuously applied fixed axial compression load of 30N, 60N, 90N respectively on time. The weight loss of magnesium alloy screws and the amount of gas generated were measured regularly. Results: From the cumulative amount of hydrogen production, group 1 and group 4 were relatively large, whereas group 2 and group 3 were relatively small. From the weight loss of magnesium alloy screws, group 3 > group 4 > group 2 > group 1. Conclusions: The general trend is the greater the load, the faster the degradation.

Effect of Nd and Dy Addition on AZ91D Ignition Temperature and Microhardness

Magnesium alloys are very active and readily ignite during heating and melting. In this study, the ignition-proof property of AZ91D with Nd and Dy addition was discussed, and the effects of these ignition-proof elements on the microstructure and microhardness of AZ91D investigated. The results show that the ignition-proof performance of magnesium alloy is improved obviously. The ignition resistance is attributed to the compact oxide films, which consist of MgO, Al2O3, Nd2O3, Dy2O3. When Dy content increased beyond 0.5%, the change tendency of ignition point of the alloy follows the shape of “v” curve, and the ignition point increased with Nd addition. The optimum composition of the newly developed magnesium alloy is AZ91D-3Nd-0.5Dy with the ignition point about 60K higher than AZ91D. And also AZ91D-3Nd-0.5Dy has fine microstructure and higher microhardness.

Research on Magnesium Alloy Melting Technology

The magnesium alloy smelting process is analyzed and designed from the protection of the melting, refining treatment, modification and many other aspects. The article puts forward the solvent and gas dual protection smelting measures that prevent the progress of chemical reaction of magnesium melt. The article also puts forward a variety of refining method for smelting process impurities and exhaust gas, It’s ensure that the qualified rate of alloy materials. In order to further improve the performance of magnesium alloy, the introduction of the modification treatment will make alloy grain refinement.Superfine grain organization will effectively improve the comprehensive mechanical properties of magnesium alloys.

Preparation of biomimetic hydrophobic coatings on AZ91D magnesium alloy surface

The hydrophobic coating has been a promising technology for improving surface performance. The surface performance of magnesium alloy has been limited in application. Furthermore, the hydrophobic of magnesium alloy is rarely investigated because magnesium alloy is an active metal alloy. In this paper, inspired by microstructure character of typical plant leaf surface such as lotus, the biomimetic hydrophobic coatings on AZ91D magnesium alloy surface were prepared by means of wet-chemical combining electroless. The samples were immersed into AgNO3 solution in wet-chemical method firstly. Then, biomimetic hydrophobic coatings were prepared by electroless after wet-method pretreatment. The microstructure was observed by SEM and the contact angles were measured by contact angle tester. The results indicated that the biomimetic hydrophobic coatings with uniform crystalline and dense structure could be obtained on AZ91D magnesium alloy surface. The results of contact angle revealed that the biomimetic nano-composite coatings were hydrophobic. The wet-chemical method treatment on the AZ91D magnesium alloy substrate provided a rough microstructure, thus improving adhesion of the coating and the substrate.

Research on Grinding Force and Surface Roughness Based on the Abrasive Belt Grinding to Magnesium Alloy

Magnesium alloy matrix quality is important for the quality of coating on the surface, and thus affecting the final performance of magnesium alloy. This paper developed a method to the abrasive belt grinding as a pre-treatment process for magnesium alloy. Based on the orthogonal test in the abrasive belt grinding of magnesium alloy, the effect of the processing parameters on grinding force and roughness has been studied. Finally, a predicting model of the grinding force and surface roughness was established by means of the neural networks. This model was verified from both the theoretical and experimental facets. The results showed that the model can be used to describe the influence of some machine tool inputs

A Comparison of Weld Properties with or without Filler Wire on Laser Welding of Magnesium Alloy for Car Industry

Magnesium alloys are becoming important material for light weight car body, due to their low specific density but high specific strength. However they have a poor weldability, caused by high oxidization tendency and low vapour temperature. In this study, the welding performance of magnesium alloy was investigated for automobile application. The material was rolled magnesium alloy sheet contains 3wt%Al, 1wt%Zn and Mg balance. The effects of filler wire addition was investigated on 2kW Nd:YAG laser welding. For the results, the mechanical properties of welded specimen were similar with base metal in laser welding with and without filler wire. The bridging ability was improved with filler wire without weld properties deterioration on laser welding of magnesium alloy.