Wear Resistance Of Magnesium Alloy Research Articles

Enhancing wear resistance of AZ61 alloy through friction stir processing: experimental study and prediction model

In this study, friction stir processing (FSP) is proposed for the treatment of AZ61 alloy, and an artificial neural network is built to predict and compare the experimental wear results. The effects of different processing parameters, including spindle speed (800–1200 rpm), traveling speed (5–15 mm min−1), and depth of press (0.8–1.2 mm) on the microstructural evolution, mechanical properties, and wear behavior are investigated. Microstructural analysis reveals a grain size of 14 ± 2 μm for the FSP1 sample, with observed shifting of x-ray diffraction (XRD) peaks, indicative of texture development. Increasing spindle and traveling speeds increase the surface roughness, as observed by average roughness (Ra) values of 68.4 nm for a rotational speed of 800 rpm, traveling speed of 5 mm min−1, and shoulder depth of 0.8 mm (FSP1) and 116.3 nm for rotational speed of 1200 rpm, traveling speed of 15 mm min−1, and shoulder depth of 1 mm (FSP9). Microhardness values increase to 113.36 Hv for FSP1 and 79. 51 Hv for FSP9 compared to 65.92 Hv for the base material (BM) sample. The decrement in hardness from FSP1 to FSP9 can be attributed to increased heat input, resulting in coarse microstructure. Wear results show that FSP1 exhibits the lowest weight loss (0.003 g) and coefficient of friction (COF) (0.28) compared to other FSP conditions and BM samples (weight loss of 0.022 g and COF of 0.68). This work demonstrates the efficacy of friction stir processing in enhancing the wear resistance of magnesium alloys.

Development of Ti/Ti-DLC multilayers on magnesium alloys. Part 1: Microstructure and mechanical properties

To improve both the corrosion resistance and wear resistance of magnesium alloys, titanium-diamond-like carbon (Ti-DLC) monolayer and Ti/Ti-DLC multilayer films with two periods were applied to AZ31 magnesium alloys through filter cathodic vacuum arc deposition technology. The Ti-DLC monolayer film exhibited an amorphous structure doped with TiC nanocrystals. After introducing the Ti sublayer, the Ti/Ti-DLC multilayer films exhibited a layered structure, resulting in improved adhesion strength and fracture toughness and lower hardness. Compared with the (Ti/Ti-DLC)4 multilayer film with a smaller period, the (Ti/Ti-DLC)2 multilayer film with a lager period exhibited better adhesion strength, higher fracture toughness, hardness, ID/IG ratio, and lower residual stress owing to its thicker Ti sublayers.

Development of Ti/Ti-DLC multilayers on magnesium alloys — Part 2: Corrosion and wear resistance

To improve corrosion and wear resistance of magnesium alloy, the Ti-DLC monolayer and Ti/Ti-DLC multilayer films were deposited on AZ31 magnesium alloys by filter cathodic vacuum arc deposition technology. All coatings showed good corrosion and wear resistance, and low friction coefficient. The corrosion resistance of the coated samples, from high to low, was Ti/Ti-DLC)2 multi coated-, Ti-DLC mono coated-, and Ti/Ti-DLC)4 multi coated samples. That is because the good toughness and film/substrate deformation coordination of multilayer films were beneficial for improving the corrosion resistance of coating, but the thinner Ti sublayer increased the risk of corrosion liquid penetrating the coating. Under friction test under 5 N load for 30 min, the Ti-DLC monolayer film showed best wear resistance with lowest wear rate as its combination effects of high hardness and good toughness. Whereas, under higher load, the higher toughness and film/substrate deformation coordination of multilayer films played a more positive role in its wear life. Under load of 10 N, comparing to the Ti-DLC monolayer film, the (Ti/Ti-DLC)4 multi and (Ti/Ti-DLC)2 multi films improved wear life by 15 % and 36 %, respectively. The (Ti/Ti-DLC)2 multi film had the best corrosion resistance and wear life.

Exploratory analysis and evolutionary computing coupled machine learning algorithms for modelling the wear characteristics of AZ31 alloy

The wear resistance of magnesium alloys is one of its key technological properties that could limit their practical application. In accordance with ASTM G99–95a standard, this study used a pin-on-disc method to analyze the wear behavior of ascast AZ31 magnesium alloy under dry-sliding conditions. With a track radius of 37.5 mm, varied sliding velocities of 0.25, 0.5, 1, and 1.5 m/s, and normal loads of 40, 60, and 90 N were employed to quantify wear rate over a fixed sliding distance of 600 m. The surface morphology of the alloy's corroded surface was investigated using a SEM/EDS. The effectiveness of two Evolutionary Computing integrated machine learning algorithms, Particle Swarm Optimization coupled Decision Tree (PSO-DT) and Particle Swarm Optimization coupled Gradient Boosting Regressor (PSO-GBR), is also compared in this study in predicting the particular wear rate of AZ31 magnesium alloy. The experimental observations of wear behavior at various sliding velocities and normal loads make up the dataset used in this study. The algorithms' prediction performance was assessed using the coefficient of determination (R2), mean squared error (MSE), and mean absolute error (MAE). The results show that when it comes to foretelling the precise wear rate of AZ31 magnesium alloy, the PSO-GBR algorithm works better than the PSO-DT algorithm resulting in the R2 value of 0.99970. The PSO-GBR algorithm's successful integration of Particle Swarm Optimization and the gradient-boosting regressor model is responsible for this higher performance. The PSO-GBR algorithm improved accuracy and better captured nonlinear patterns in the data by improving the algorithm's parameters and capturing complex wear mechanisms.

Preparation and properties of TiP/Mg-RE composites through laser melt injection

Hardness and wear resistance of magnesium alloys should be improved without reducing mechanical properties to realize their widespread application. By adding metal particles into magnesium instead of ceramic particles can reducing the influence caused by large difference of thermophysical and mechanical properties between ceramics and Mg. The existing methods for Mg based composites are time-consuming, cause agglomeration, and not suitable for preparing complex surfaces. In this study, Ti particles were injected into Mg-RE alloy through laser melt injection. Results show that the prepared TiP/Mg-RE composites with large surface area have no obvious welding defects in microstructure. Ti particles have good metallurgical bonding with the Mg-RE matrix. Microhardness of the TiP/Mg-RE composites is 100% higher than that of the Mg-RE matrix, at a cost of reducing partial mechanical properties. Moreover, the composites showed a stable friction coefficient and running-in stage. The TiP/Mg-RE composites show excellent comprehensive properties in a summary.

Joining of Magnesium Alloy with Hard Laminates by Shot Peening

Magnesium alloys are increasingly being used in the field of transportation equipment, such as automobiles and aircraft, where energy saving is being promoted. However, the problem with magnesium alloys is that they have lower corrosion and wear resistance than steel materials. Therefore, a lot of research on alloy development and surface modification has been attempted. In the present study, to improve the corrosion resistance and wear resistance of magnesium alloys, dissimilar materials were joined using shot peening. Using a cast steel projection material having a diameter of 1 mm, the projection was performed at a projection speed of 60 m / s and a processing temperature of 300 ° C. The base alloys are AZ31, AZ61, AZX611, and AZ91D. The dissimilar material was an aluminum laminated material containing ceramic powders and a heat-resistant resin sheet. The ceramic powders were alumina and zirconia, with a particle size of 0.1 to 0.3 mm. Resin was a sheet of polyimide, with a thickness of 0.025 mm. The joinability was determined by microstructure observation and bending test. The three-point bending test destroyed the joint surface, but did not cause peeling of dissimilar materials from the substrate. It was also found that wear resistance was improved by joining hard dissimilar materials.

Analysis and Development Review of Metal and Metal/Ceramic Composite Coating Prepared on Magnesium Alloy Surface

Magnesium, as one of the lightest metal structural materials, also has its advantages such as high specific strength, good electromagnetic shielding characteristics, good processability and easy recycling, so it has a wide application prospect. However, its poor insulation, corrosion resistance, wear resistance and other properties limited it to be an alloy that can be used in a large area. Therefore, how to improve the corrosion resistance and wear resistance of magnesium alloy is the key to promote the development of magnesium alloy field. This paper reviews the research progress of using magnetron sputtering technology to prepare ceramic composite film on the surface of magnesium alloy and briefly introduces the film corrosion resistance and wear resistance of the thin films. It analyzes the impact of metal transition layer, process parameters and other factors on structure and properties of metal / ceramic coatings and prospects for the development prospects of magnetron sputtering in the field of magnesium alloy surface protection.

Fretting Wear Behavior of Micro-Arc Oxidation Coating Fabricated on AZ91 Magnesium Alloy

Abstract In this study, the effect mechanisms between the fretting wear behavior and properties of micro-arc oxidation (MAO) coatings fabricated by different anodic voltages (AVs) on AZ91 magnesium alloy were investigated. The microstructure and macroscopic mechanical properties of the MAO coatings were analyzed by various characterization means. The evolution rule of fretting wear behaviors was carried out through sliding fretting wear experiment under different test parameters. The results showed that the increase in AV increased the MAO coating surface roughness and elastic modulus. The fretting wear resistance of magnesium alloy also enhanced after treatment by MAO, and the improvement effect was positively correlated to AV. Further studies revealed that the wear mechanisms of AZ91 magnesium alloy were oxidation wear and fatigue spalling, and that of MAO coating was mixed abrasive wear and fatigue spalling.

Optimizing the effect of wear test parameters on the specific wear rate of AZ91D magnesium alloy

Due to low densities, magnesium (Mg) alloys are highly used in the automotive and aerospace industry to decrease the weight of components and thus in turn to slash the fuel consumption and emission of greenhouse gases. The poor wear resistance of magnesium alloys restricts their use in many applications. In the present study, the effect of wear test parameters on as-received AZ91D magnesium alloy was analyzed by conducting pin-on-disc wear experiments. The parameters considered in this study were applied load (AL), sliding speed (SS), and sliding distance (SD). Optimization of wear test parameters was done using response surface methodology, and a quadratic model was established by incorporating these parameters to predict the Specific Wear Rate (SWR). The results indicated that the proposed model correlated well with the experimental results. The Specific Wear Rate had a direct relationship with AL and SD however varied inversely with SS. The AL of 44.74 (N), SS of 1.77 (m/s) and SD of 521.12 (m) were the optimized parameters proposed by the mathematical model.

Improved wear resistance of biodegradable Mg–1.5Zn–0.6Zr alloy by Sc addition

Magnesium alloys exhibit significant potential for use in next-generation biodegradable materials. Implanted magnesium alloys are expected to exhibit good wear resistance. In this work, the effects of rare earth metal Sc on the wear resistance of biodegradable magnesium alloys were studied. The average grain sizes of Mg–1.5Zn–0.6Zr–xSc (ZK21–xSc, x = 0, 0.2, 0.5, 1.0; wt%) alloys decreased with Sc content increasing. Unlike other rare earth metals, the grain refinement mechanism of Sc belongs to the heterogeneous nucleation mechanism. The yield tensile strengths and Vickers hardness of the ZK21–xSc alloys markedly improved with the addition of Sc increasing. This could be due to the grain refinement and enhanced bond energy resulting from Sc addition. Moreover, the friction and wear tests showed that the friction coefficient of the alloys decreased and the weight loss reduced with Sc addition increasing. This implies that Sc addition could enhance the wear resistance of magnesium alloys. With the addition of Sc increasing, the peeling phenomenon weakened gradually and the worn surfaces of samples became smoother. The major wear mechanisms of the as-cast ZK21–xSc alloys were abrasion wear and delamination wear.

Lining of Light Metals with Dissimilar Materials by Shot Peening

Since aluminum and magnesium are lightweight, they are used as parts of transportation equipment such as automobiles and aircraft. Magnesium alloys have attracted attention because of their characteristics of light weight, high specific strength and recyclability. However, the problem is that the wear resistance and corrosion resistance are considerably lower than steel materials. In this study, to enhance the surface properties such as corrosion resistance and wear resistance of magnesium alloys, we attempted to bond dissimilar materials to the alloy surface using shot peening (SP). The surface characteristics of the magnesium alloy were improved by dissimilar material bonding using SP.

Cold arc cladding of aluminum coatings on AZ61 magnesium alloy: A comparative study

The corrosion resistance and wear resistance of magnesium alloys seriously restrict their applications in industry. The objective of this work is to provide a comprehensive understanding, including parameters, microstructure and properties, of the cold arc cladding process of aluminum coatings on AZ61 magnesium alloy. Three kinds of cladding wires, Al-Mn alloy (AlMn1), Al-Si alloy (AlSi5) and Al-Mg alloy (AlMg5), were cladded on the surface of AZ61 magnesium alloy by pulsed direct current (P-DC) cold arc for a comparative study. The study revealed a correlated relation between the clad geometry and the heat input during the deposition process. The microstructure and composition of the coatings were carefully studied by SEM, EDS and XRD. The properties of the coatings were studied by the micro-hardness, wear resistance and electrochemical corrosion test. The Al-Mn alloy coating has the highest hardness, which is three times that of the AZ61 magnesium matrix. The Al-Si alloy coating has the lowest wear rate, which is about 13.9% of the Mg matrix. The corrosion performance of the Al-Mg alloy coatings is significantly improved byα-Al phase compared to the Mg matrix.

Enhanced corrosion and wear resistance of AZ31 magnesium alloy in simulated body fluid via electrodeposition of nanocrystalline zinc

In order to prolong the service life of magnesium-based implants in the human body, nanocrystalline zinc (30 nm) was electrodeposited on AZ31 magnesium alloy, its electrochemical and tribological properties in simulated body fluid (SBF) were investigated. It was demonstrated that electrodeposition of nanocrystalline zinc resulted not only in more than 4 times increase in corrosion resistance, but also in a significant enhancement in corrosive wear resistance of magnesium alloy. Detailed analyses were conducted to clarify the mechanism responsible for performance improvements. This is a biocompatible, economical and simple approach with the promise for large-scale application in surface modification of magnesium alloy implants.

Tribological behavior of in-situ nanosized TiB2 particles reinforced AZ91 matrix composite

To enhance the wear resistance of magnesium alloy to expand its applications, AZ91 matrix composite reinforced with TiB2 particles was developed by in-situ casting, and its tribological behavior was investigated. The dry sliding wear experiment was carried out with the sliding speeds of 0.25, 0.50 and 0.75 m/s, at different normal loads of 12.5, 25 and 37.5 N respectively. The hardened AISI 52100 bearing steel was selected as counterbody material. The experimental results reveal that the mechanical properties of composite are improved significantly due to grain refinement and numerous dislocations formed near TiB2 particles. The wear rate of composite reduces with the increase of sliding speeds at all normal loads and wear mechanism is transited from abrasive and mild oxidation wear to delamination and severe oxidation wear, similar to the wear mechanism in various normal loads. However, the mechanically mixed layer formed at higher speeds has a protective effect and the delamination and plastic deformation of subsurface is more severe at higher loads. The wear resistance of composite is greater than that of the matrix at all wear conditions, because TiB2/AZ91 composite possess improved hardness and strength, as well as increased work hardening capacity of subsurface due to the presence of nanosized TiB2 particles.

Evaluation of corrosion and wear resistance of friction stir welded ZK60 alloy

ABSTRACTOwing to the low corrosion and wear resistance of magnesium alloy, surface properties are the key factors affecting its application. But few studies have concentrated on the surface properties of friction stir welded Mg–Zn–Zr alloy. The aim of the present paper is to investigate the effects of friction stir welding (FSW) and subsequent ageing on the surface corrosion and wear resistance of ZK60 alloy. It is found that due to the significant grain refinement and redistribution of precipitates, the surface corrosion and wear resistance of ZK60 plates are enhanced by FSW. Morphology of inter-granular corrosion in base metal is changed into pitting corrosion after welding. Subsequent ageing can significantly reduce the corrosion resistance of the welded plates.

Composite Layers “MgAl Intermetalic Layer / PVD Coating” Obtained On The AZ91D Magnesium Alloy By Different Hybrid Surface Treatment Methods

Abstract Magnesium alloys have very interesting physical properties which make them ‘materials of the future’ for tools and machine components in many industry areas. However, very low corrosion and tribological resistance of magnesium alloys hampers the implementation of this material in the industry. One of the methods to improve the properties of magnesium alloys is the application of the solutions of surface engineering like hybrid technologies. In this paper, the authors compare the tribological and corrosion properties of two types of “MgAlitermetalic / PVD coating” composite layers obtained by two different hybrid surface treatment technologies. In the first configuration, the “MgAlitermetalic / PVD coating” composite layer was obtained by multisource hybrid surface treatment technology combining magnetron sputtering (MS), arc evaporation (AE) and vacuum heating methods. The second type of a composite layer was prepared using a hybrid technology combined with a diffusion treatment process in Al-powder and the electron beam evaporation (EB) method. The authors conclude, that even though the application of „MgAlitermetalic / PVD coating” composite layers can be an effective solution to increase the abrasive wear resistance of magnesium alloys, it is not a good solution to increase its corrosion resistance.

Wear performance of nano-Al2O3 particles and CNTs reinforced magnesium matrix composites by friction stir processing

To improve the wear resistance of magnesium alloys, nano-alumina (n-Al2O3) particles and carbon nano-tubes (CNTs) reinforced AZ31 magnesium alloy matrix composites and hybrid composites were fabricated by friction stir processing (FSP), and the friction and wear performance was investigated. The composites contain reinforcement of 0.3%CNTs, 0.1%A12O3+0.2%CNTs, 0.15%A12O3+0.15%CNTs, 0.2%A12O3+0.1%CNTs and 0.3% A12O3. The dry wear tests were carried out at room temperature, with the normal load of 0.65Mpa, 1.30MPa, 1.95MPa, 2.60MPa and 3.25MPa, correspondingly. The counterface material was 5140 alloy steel. The microstructure of the fabricated composites was void of obvious defect, with the reinforcements evenly distributed in the matrix. All the composites were more resistant in wear than FSP AZ31 alloy. The wear of the n-Al2O3 independently reinforced composite is lower than that of the CNTs independently reinforced composite; however, its friction coefficient is higher. Certain combination of n-A12O3 and CNTs possessed hybrid effect on the wear performance of the hybrid composites, because they had hybrid effect on the hardness and friction coefficient of the composites. When the load was higher than 1.95MPa, the wear of (0.1%A12O3+0.2%CNTs)/AZ31 hybrid composite was considerably lower than those of other composites and its friction coefficient was obviously lower than those of other composites. The wear mechanism of the composites was abrasive wear when the normal load was lower than 1.30MPa; otherwise it was delamination wear of the mechanically mixed layer.

Friction Stir Processing for Enhancement of Wear Resistance of ZM21 Magnesium Alloy

Present work pertains to surface modification of the magnesium alloy using friction stir processing (FSP). Silicon carbide and boron carbide powders are used in the friction stir processing of the ZM21 Magnesium alloy. Coating was formed by FSP of the alloy by placing the carbide powders into the holes made on the surface. Surface coating was characterized by metallography, hardness and pin-on-disc testing. Friction stir processed coating exhibited excellent wear resistance and is attributed to grain boundary pinning and dispersion hardening caused by carbide particles. Surface composite coating with boron carbide was found to possess better wear resistance than coating made with silicon carbide. This may be attributed to formation of very hard layer coating of boron carbide reinforced composite on the surface of magnesium alloy. In the present work an attempt has also been made to compare the wear behaviour of surface composite layer on ZM21 Mg alloy with that of conventionally used engineering materials such as mild steel and austenitic stainless steel. Wear data clearly shows that wear resistance of friction stir processed composite layer is better than that of mild steel and stainless steel. This work demonstrates that friction stir processing is an effective strategy for enhancement of wear resistance of magnesium alloys.

A Brief Review about Surface Treatment of Magnesium Alloys

Due to the low density and high specific strength, magnesium and its alloys have been extensively used in the automobile and aerospace applications, where the weight reduction is critical. However, they are highly prone to corrosion, which has greatly limited their application in the automotive and aerospace industries. This paper briefly reviews the technologies for improving the corrosion and wear resistance of magnesium alloys and finds that the widespread application of magnesium alloys is still limited by the lack of proper protective coatings. Therefore, there is still a need to explore new materials and methods for the effective protection of magnesium and its alloys.

Mechanical Properties, Aging Behavior and Microstructure Evolution of Mg-Nd-Zn-Zr Based Magnesium Matrix Composite Reinforced with Alumina Fibers

Metal matrix composites reinforced with discontinuous reinforcement (short fiber, whisker or particle) are attractive for applications requiring higher stiffness and strength than traditional alloys. Unlike continuously reinforced composites, where the properties are mainly influenced by fibers, the properties of the discontinuously reinforced composites seem to be influenced more by matrix properties. Most of the discontinuously reinforced composites are based on age-hardenable light alloys, so that aging treatments can be applied to develop the optimum properties of the composites. The aging behavior of discontinuously reinforced composites has been a subject of great interest both from scientific and technological view points. Recently developed NZ30K (Mg-3wt.%Nd-0.5wt.%Zn-0.5wt.%Zr) alloys exhibit higher specific strength at both room and elevated temperatures, better strength and creep resistance than the existing commercial magnesium alloys. Accordingly, this alloy can be considered as a candidate material for potential automobile applications, such as engine blocks and pistons, which experience high service temperature. Its use could save considerable mass weight in powertrain systems. However, low elastic modulus and wear resistance of magnesium alloys limit their widespread applications. Metal matrix composites have been proposed as the feasible and economical solution. The aim of this study is to investigate the effect of alumina fibers on the aging hardening kinetics and age-hardening efficiency of squeeze cast NZ30K/Saffil/15p magnesium matrix composite. The aging behavior has been examined using Vickers, combined with microstructure observation developed during heat treatment by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).