Wyniki wyszukiwania - BazTech

1

Tribological Properties of PEO Coatings Produced on Ultralight Magnesium Alloy in Contact with Plastic Materials

Niedźwiedź Mateusz, Bara Marek, Korzekwa Joanna

Tribologia

|

2025

|

nr 4

37--49

EN

This article presents the results of tribological studies of oxide coatings produced by plasma electrochemical oxidation (PEO) on an ultralight LA141 magnesium alloy. The coatings were obtained using identical process parameters, a rectangular voltage waveform, and an alkaline ternary electrolyte. The process was conducted under constant conditions: a peak current density of 15 A/dm², an oxidation time of 12 minutes, and a pulse frequency of 1,800 Hz, which allowed for the formation of homogeneous protective coatings. Tribological tests were conducted using a T-17 tester under technically dry friction conditions in a reciprocating motion. Four materials were used as counter-samples: PEEK, PEEK-HPV, T5W, and T7W. In addition to tribological tests, profilographometric measurements of the coating surface topography were performed before and after the tests, allowing for an analysis of the nature of wear. The studies enabled the assessment of wear resistance and of the effect of the counter-sample material type on the friction coefficient and wear mechanisms. The research was supplemented with measurements of coating thickness and microscopic imaging. The results confirm that the counter-sample materials influence the tribological properties of the tested coatings.

PL

W artykule przedstawiono wyniki badań tribologicznych powłok tlenkowych wytworzonych metodą plazmowego utleniania elektrochemicznego (PEO) na ultralekkim stopie magnezu LA141. Powłoki uzyskano przy zastosowaniu identycznych parametrów procesu, wykorzystując prostokątny przebieg napięcia oraz alkaliczny elektrolit trójskładnikowy. Proces prowadzono przy stałych warunkach: szczytowa gęstość prądu 15 A/dm², czas utleniania 12 minut, częstotliwość impulsów 1800 Hz, co pozwoliło na uzyskanie jednorodnych powłok ochronnych. Testy tribologiczne przeprowadzono przy użyciu testera T-17 w warunkach tarcia technicznie suchego, w ruchu posuwisto-zwrotnym. Jako przeciwpróbki zastosowano cztery tworzywa: PEEK, PEEK-HPV, T5W oraz T7W. Oprócz badań tribologicznych przeprowadzono również profilografometryczne pomiary topografii powierzchni powłok przed i po testach, co umożliwiło analizę charakteru zużycia. Badania pozwoliły na ocenę odporności na zużycie oraz wpływu rodzaju materiału przeciwpróbki na współczynnik tarcia i mechanizmy zużycia. Badania uzupełniono o pomiary grubości powłoki oraz jej obrazowanie mikroskopowe. Wyniki badań potwierdzają wpływ rodzaju materiału przeciwpróbki na właściwości tribologiczne badanych powłok.

2

Selected Problems of Effectiveness and Quality in the Dry Rough Milling of Magnesium Alloy AZ91D Using End Mills with Different Helix Angles

Zagórski Ireneusz, Korpysa Jarosław, Kulisz Monika, Skoczylas Agnieszka

Management and Production Engineering Review

|

2025

|

Vol. 16, No. 3

[nr art. 10], s. 1--21

EN

From the point of view of production and manufacturing processes, issues related to surface quality and machining efficiency are very important. This paper presents the results of a study investigating selected problems of quality and efficiency in dry rough milling. Roughness parameters 2D and 3D were analysed. Additionally, 3D surface topography maps and Abbott– Firestone curves were generated. Carbide end mills with different helix angles were used in the study. Experiments were conducted on AZ91D magnesium alloy specimens. The machining process was conducted using high-speed machining parameters. The results showed that the surface roughness of the AZ91D alloy depended to a great extent on the tool geometry and applied machining parameters. Moreover, ANOVA statistical analysis and post-hoc tests (Tukey) were performed to assess the differences between individual groups of the specimens. Additionally, an artificial neural network (ANN) model was developed to predict the Ra parameter, and the results demonstrated its high predictive accuracy (R = 0.966).

3

Role of Reinforcements on Mechanical and Wear Behaviour of AZ91D Hybrid Composites

Narendra Babu Y., Vijay Praveen D., Umamaheswarrao P., Ratna Sunil Buradagunta, Krugon Seelam

Archives of Metallurgy and Materials

|

2025

|

Vol. 70, iss. 2

1003--1009

EN

Composite materials offer a versatile and customizable solution for various industries, allowing for innovative designs and improved performance. Magnesium-based composites offer a compelling combination of lightweight, high strength, and other desirable properties, making them valuable materials for a variety of applications. The present study is focused on the microstructural, mechanical and wear characterization of the magnesium based hybrid composites which are developed with different combinations of Al2O3 and B4C microparticulates through stir casting route. The microstructural study reveals the diversity in the particle phase distribution. Composite with 2% Al2O3 and 6% B4C have shown higher hardness (78.5 HV0.2 and 67.3 HV0.2, respectively) and yield strength (273 MPa and 219 MPa, respectively) as compared to the other compositions. Furthermore, pin on disc test was conducted on the developed composites to study the wear and friction behavior. Test results revealed that the composite with 2% Al2O3 and 6% B4C has better wear resistance due to its superior mechanical properties as compared to the other developed composites. The results demonstrated the positive role of reinforcements in the AZ91D alloy, which can be a promising material for manufacturing structures and components in the automotive sector.

4

Influence of Deformation Process Parameters on Changes in Microstructure and Properties of Mg-8Li-2Ca Alloy

Bednarczyk Iwona

Archives of Foundry Engineering

|

2025

|

Vol. 25, iss. 2

81--88

EN

Currently, the aviation and automotive industries are seeing increasing interest in magnesium alloys. The manufacture of semi-finished and finished magnesium alloy products is mainly based on casting technology, which results from the good casting properties of these materials. There are some difficulties using plastic processing for magnesium alloys but it offers better mechanical properties. For these reasons, alternative ways of plastic forming are being sought for magnesium alloys. Research has also been undertaken into the development of production and forming technology of a new group of ultralight Mg-Li-Ca magnesium alloys, using conventional (classical extrusion) and unconventional plastic forming methods (KoBo extrusion). The paper presents the results of the study on plastic forming of Mg-8Li-2Ca alloy. The research material consisted of ingots with the dimensions ϕ 40 x 90 mm. Before the deformation process, the ingots were subjected to heat treatment. Classical extrusion tests and extrusion by SPD methods (KoBo) were performed. Using light and electron microscopy, the changes formed in the microstructure of the Mg-8Li-2Ca alloy in the initial state and after plastic deformation processes (classical extrusion, KoBo extrusion) are presented. Quantitative analysis of the microstructure of the Mg-8Li-2Ca alloy was performed using Metilo software after the deformation process. The mechanical properties were evaluated based on the results from the conducted HV0.2 hardness measurements and the static tensile test performed at room temperature.

5

Evolution of microstructure, texture, and mechanical performance of Mg-13Gd-2Er-0.3Zr alloy by double extrusion at different temperatures

Khan Muhammad Abubaker, Afifi Mohamed A., Hafeez Muhammad Arslan, Chaudry Umer Masood, Brechtl Jamieson, Zulfiqar Maryam, Tariq Hafiz Muhammad Rehan, Hussain Muhammad Asif, Kamran Muhammad, Ishtiaq Muhammad, Manzoor Muhammad Umar, Mansoor Adil, Jabar Bushra

Archives of Civil and Mechanical Engineering

|

2025

|

Vol. 25, no. 1

art. no. e26, 2025

EN

This study investigates a novel Mg-13Gd-2Er-0.3Zr (weight percent) alloy, focusing on the influence of varying double extrusion temperatures (390 °C–450 °C) on the evolution of grain structure, texture, and mechanical properties of double-extruded (DE) alloys. Results show that double extrusion markedly refines the recrystallized grains and enhances the dispersion of fine secondary precipitates, thereby significantly improving the tensile properties compared to a single extruded alloy. A notable increase in the dynamic recrystallization (DRX) and grain size is observed as the deformation temperature rises, with grain sizes enlarging from 2.2 µm at 390 °C to 10.2 µm at 450 °C. The DE alloy extruded at 390 °C demonstrates superior mechanical properties, which was attributed to the synergistic effects of refined recrystallized grains, the presence of un-recrystallized (un-DRXed) grains, abundant fine precipitates, and a weakened basal texture. Additionally, this study highlights that a lower fraction of fine precipitates and a higher fraction of DRX grains contribute effectively to the improvement of elongation (EL) in DE alloys which is ~ 75% higher in the DE alloy at 430 °C than the single extruded alloy. This comprehensive analysis underscores the critical role of extrusion temperature in tailoring the microstructure and mechanical performance of Mg-13Gd-2Er-0.3Zr alloy, offering valuable insights for optimizing the properties of magnesium alloys for industrial applications.

6

Corrosion behavior of nano bio coating on AZ31 magnesium alloy by electrophoretic deposition for biomedical application

Radhi Maream Ali, Mustafa Ali Mundher, Abdulkareem Makarim H.

Advances in Science and Technology. Research Journal

|

2025

|

Vol. 19, no. 8

296--312

EN

Magnesium alloy AZ31 is a promising material for biodegradable implants due to its mechanical similarity to bone and its natural degradation in the body, eliminating the need for surgical removal. However, its clinical application is limited by rapid corrosion and susceptibility to bacterial colonization. This study addresses these challenges by applying nano-scale bioactive coatings of hydroxyapatite (HA) and calcium oxide (CaO) onto AZ31 using electrophoretic deposition (EPD). Coatings were deposited under optimized conditions (20 V, 4 minutes, 5 wt%) and evaluated for morphology, thickness, wettability, antibacterial activity, and bioactivity. Single and multilayer coatings showed thicknesses from 21.23 µm to over 100 µm. SEM and EDS analyses confirmed uniform, crack-free coatings with strong adhesion. Zeta potential measurements above +30 mV indicated stable suspensions, while contact angle measurements revealed significantly enhanced hydrophilicity, especially in triple-layer coatings, which showed a contact angle as low as 1. 58°.Antibacterial assays demonstrated strong inhibition of Staphylococcus aureus, with inhibition zones up to 46 mm, while the uncoated alloy showed no antibacterial effect. After 14 days in simulated body fluid, all coated samples exhibited apatite formation, indicating improved bioactivity. The best performance was observed in the triple-layer configuration (CaO + (HA+CaO) + HA), which achieved the lowest corrosion current density (0.0619633 µA) and the highest corrosion potential (-895.349 mV). These results indicate that this multilayer coating forms an effective protective barrier against corrosion and enhances the biological performance of AZ31.Overall, nano HA/CaO multilayer coatings significantly improve the corrosion resistance, antibacterial properties, and bioactivity of AZ31, supporting their potential use in biodegradable implant applications.

7

The Influence of Graphite Modification of Oxide Coatings Produced on MG-AZ31B Alloy by Plasma Electrolytic Oxidation on their Tribological Properties

Niedźwiedź Mateusz, Bara Marek, Korzekwa Joanna

Tribologia

|

2024

|

nr 3

107--118

EN

The manuscript discusses the impact of graphite modification of oxide coatings formed on the AZ31B magnesium alloy through plasma electrolytic oxidation on tribological properties. Constant oxidation parameters were applied: current density of 18 A/dm2, oxidation time of 30 minutes, pulse frequency of 100 Hz, and voltage limitation in positive current cycles of 400 V. Graphite modification was carried out using an ultrasonic method, with process parameters (modifier content and treatment time) selected based on a two-dimensional experimental design. Tribological tests were performed on a T-17 tester under dry friction conditions using a PEEK-HPV pin. Graphite modification resulted in a reduction in the friction coefficient and mass wear of the pin, as well as an increase in the mass change of the sample. Additionally, roughness and coating thickness measurements were carried out.

PL

W artykule omówiono wpływ modyfikacji grafitem powłok tlenkowych wytworzonych na stopie magnezu AZ31B poprzez plazmowe utlenianie elektrolityczne na właściwości tribologiczne. Zastosowano stałe parametry utleniania: gęstość prądu 18 A/dm2, czas utleniania 30 minut, częstotliwość impulsów 100 Hz oraz ograniczenie napięciowe w cyklach prądu dodatniego 400 V. Modyfikację grafitem przeprowadzono wykorzystując metodę ultradźwiękową, a parametry procesu (zawartość modyfikatora i czas obróbki) zostały dobrane na podstawie dwuwymiarowego planu badawczego. Testy tribologiczne przeprowadzono na testerze T-17 w warunkach tarcia technicznie suchego z użyciem trzpienia PEEK-HPV. Modyfikacja grafitem wpłynęła na zmniejszenie współczynnika tarcia i zużycia masowego trzpienia, a także na wzrost zmiany masy próbki. Ponadto przeprowadzono pomiary chropowatości oraz grubości powłok.

8

Comparative analysis of microstructure and selected properties of WC-Co-Cr coatings sprayed by high-velocity oxy fuel on S235 and AZ31 substrates

Jonda Ewa, Myalska-Głowacka Hanna, Łatka Leszek, Szymański Krzysztof, Dziekońska Małgorzata

Materials Science Poland

|

2024

|

Vol. 42, No. 1

32--41

EN

The purpose of this work was to carry out comparative studies of WC-Co-Cr coatings deposited using the high velocity oxy fuel (HVOF) method onto two types of substrate material: structural steel S235 and magnesium alloy AZ31. The influence of the substrate material type on the microstructure, phase composition, crystallite size, porosity, Vickers microhardness, instrumental hardness (HIT), Young’s modulus (EIT), and fracture toughness was investigated. For both substrates, the deposited coatings deposited were characterized with fine-grained and compact microstructure. The X-ray diffraction (XRD) revealed presence of following phases: WC, W2C, Co0.9W0.1, and Co3W9C4. The WC phase was the most desirable and stable one with crystallites were below 100 nm. On the other hand, the size of the W2C crystallites was below 30 nm. The coatings obtained showed porosity values equal to 2.3 ± 0.4 vol% and 2.8 ± 0.7 vol% for AZ31 and S235, respectively. The average Vickers microhardness for both types of sample was appproximately 1200 HV0.3. The average HIT values for carbide particles and metallic matrix were around 29 GPa and 6.5 GPa, respectively. In the case of EIT, it was around 620 GPa and 190 GPa for WC and Co-Cr, respectively. The differences between coatings were negligible. The EIT value for both coatings was equal to 344 ± 11 GPa. The fracture toughness was around 4.5 MPa · m1/2 in both cases. The investigations revealed that it is possible to replace steel substrate material with a much lighter equivalent, in this case AZ31 alloy, without deterioration of the coating properties.

9

Experimental investigation and machining analysis of Mg/TiC composites during EDM

Dash Dharmeswar, Devarajaiah Devarasiddappa, Dash Santosh Kumar, Samanta Sutanu, Rai Ram Naresh

Composites Theory and Practice

|

2024

|

R. 24, nr 1

9--16

EN

Electrical discharge machining (EDM) is one of the prominent non-conventional machining processes used to machine metal matrix composites. Mg/TiC composites are found in many industrial applications and conventional machining of the same is highly challenging. This paper aims to study the machinability analysis of Mg/TiC composites using EDM with pulseon time (Ton), pulse-off time (Toff) and input current (I) as the process variables with the material removal rate (MRR) and surface roughness (SR) as the performance measures. Stir cast Mg-alloy reinforced with TiC (0, 5, 10, 15 and 20) by weight was used as the workpiece. The EDM experiments were conducted as per L25 orthogonal array (OA) and the results were analyzed to study the effect of the process variables on MRR and SR. The parametric study showed that SR increases linearly with Ton and is attributed to larger craters produced at a higher pulse energy. MRR was also observed to grows with the rise in Ton as more material melts due to high-intensity pulses. As per the ANOVA results, Ton was found to be the most influential process variable affecting SR and MRR with a 79% and 34% contribution, respectively. Surface morphology investigations using SEM micrographs revealed the presence of globules and sphere-shaped metal deposits and were found responsible for increased SR.

10

Effect of Tin (Sn) Addition on the Corrosion Behavior of Hydroxyapatite (HAP) Coated Mg/MgSn Alloys using Different Coating Methods

Salleh Siti Hawa Mohamed, Malek Rohaya Abdul, Zaidi Nur Hidayah Ahmad, Abdullah Salmie Suhana Che, Khantachawana Anak, Błoch Katarzyna

Archives of Metallurgy and Materials

|

2024

|

Vol. 69, iss. 3

1199--1204

EN

This study investigates the effect of tin (Sn) addition on the corrosion behavior of hydroxyapatite (HAP) coated Magnesium (Mg)/MgSn alloys by using two different coating methods. Mg/Mg alloys have gained significant attention in recent years due to their lightweight, high strength, and potential for use in a wide range of industrial applications. However, their corrosion properties during cathodic reactions with abundant hydrogen evolution have limited their widespread use, particularly in biomedical applications. In this study, pure Mg, Mg2Sn, Mg3Sn, Mg4Sn, and Mg5Sn alloys were prepared by powder metallurgy method. Then samples were coated by two different methods, dip-coating and electro-deposition. Potentiodynamic polarization and hydrogen evolution reaction analysis were performed to evaluate the corrosion rate and the hydrogen volume released from the alloys. The results indicate that the addition of Sn does not significantly increase the corrosion resistance of MgSn alloys. However, the current density and hydrogen evolution of the alloys are apparently improved after the coating process. The better corrosion resistance was observed for the Mg with higher composition, which are Mg4Sn and Mg5Sn. Overall, the study demonstrates that coating HAP onto the surface of MgSn alloys is able to improve their corrosion behavior and suppress the hydrogen evolution rate (HER) of the MgSn alloys. This improvement in other ways will increase their potential for industrial applications specifically in biomedical applications.

11

Latest advances in extrusion processes of light metals

Leśniak Dariusz, Zasadziński Józef, Libura Wojciech, Gronostajski Zbigniew, Śliwa Romana, Leszczyńska-Madej Beata, Kaszuba Marcin, Woźnicki Antoni, Płonka Bartłomiej, Widomski Paweł, Madura Jacek

Archives of Civil and Mechanical Engineering

|

2024

|

Vol. 24, no. 3

art. no. e184, 2024

EN

The paper presents a review of the literature and authors’ research on the current achievements in the field of extrusion of aluminium alloys, magnesium alloys, powders and aluminium-based composites in particular. The microstructure transformations taking place during homogenisation of billets from the medium- and high-strength heat-treatable aluminium alloys are still an object of interest of researchers. The recently published papers are related to dissolution of soluble phases formed during solidification and elimination of microsegregation, precipitation of the dispersoids, insoluble phases’ transformation as well as particles re-precipitation during cooling. The novelties in the extrusion of magnesium alloys and aluminium-based composites are shortly reported. Specifics of the extrusion dies design and their working conditions, which limit the products quality and working life of the tools, are extensively reported. The computer-aided designing (CAD) and finite-element method (FEM) and 3D optical scanning were used in analysis aimed at dimensional deviations of the dies and the extruded products. The surface engineering techniques such as welding techniques, diffusion layers and protective coatings such as produced by physical vapour deposition (PVD), plasma-enhanced physical vapour deposition (PAPVD), chemical vapour deposition (CVD) and plasma-enhanced chemical vapour deposition (PECVD) are described. Various original methods of extrusion including the severe plastic deformation processes (SPD), such as cyclic extrusion compression (CEC), equal-channel angular pressing (ECAP) and hydrostatic extrusion (HE) are discussed. The above techniques as well as the new KOBO extrusion process with oscillating die movement generate significant refining of the microstructure of metals and alloys and enable consolidation of the powdered materials. The application of the rapid solidification process connected with the hot extrusion permits production of beneficial microstructure and above-standard mechanical properties of the extruded products. Finally, the opportunities and directions of development of the extrusion process of metals and alloys are indicated.

12

Influence of temperature and number of passes during twist channel angular pressing (TCAP) on the microstructural, mechanical, and corrosion properties of Mg-4Li-Ca

Bednarczyk Iwona, Dobkowska Anna, Hilšer Ondřej, Rusz Stanislav, Pastrňák Martin, Čada Radek, Jabłońska Magdalena, Tkocz Marek, Kowalczyk Karolina, Palgan Daria, Necas David, Mizera Jarosław

Archives of Civil and Mechanical Engineering

|

2024

|

Vol. 24, no. 2

art. no. e89, 2024

EN

In this study, the possibilities of improving the mechanical and corrosion properties of Mg-4Li-1Ca processed using twist channel angular pressing (TCAP) were investigated. There was a special focus on the optimization of the TCAP parameters through analyzing how the temperature of TCAP influences the microstructural, mechanical, and corrosion properties of the alloy, and how an increasing number of TCAP passes affects these properties. It was shown that among specimens extruded with one pass, the highest mechanical properties were achieved at 180 °C. Microstructural changes were noted at higher temperatures and caused a decline in the mechanical properties. The influence of an increasing number of passes through the TCAP channel was rather minor and did not lead to significant microstructural strengthening. In contrast, the best corrosion performance was observed after four passes at 180 °C and after a single pass at 300 °C. The results of this study show that TCAP is an efficient method for the grain refinement of hcp-structured metals, lowering the costs of the plastic deformation of Mg-based alloys.

13

Powierzchniowa obróbka wibro-ścierna klamek ze stopu magnezu AZ91

Gołąbczak Marcin, Woźniak Kazimierz, Wincenciak Mariusz, Gołąbczak Andrzej, Jędrzejczak Anna, Niewiadomski Michał

Obróbka Metalu

|

2023

|

nr 3

27--33

PL

Przedstawiono wyniki badań dotyczące wpływu warunków obróbki wibro-ściernej na kształtowanie morfologii i struktury geometrycznej powierzchni klamek ze stopu magnezu AZ91. Zakres prezentowanych badań obejmował obróbkę odlewanych klamek ze stopu magnezu w wygładzarce wibro-ściernej z zastosowaniem różnego typu kształtek ściernych ceramicznych, żywicznych i porcelanowych oraz ich wybłyszczania i suszenia granulatem z kolby kukurydzy w suszarce wibracyjnej. Pomiary morfologii i struktury geometrycznej powierzchni klamek ze stopu magnezu wykonano po każdym etapie obróbki wibro-ściernej z zastosowaniem mikroskopu i profilometru optycznego.

EN

In the paper there were presented the results of studies on the influence of vibration-abrasive treatment conditions on the morphology and geometric structure of surfaces of handles made of magnesium alloy AZ91. The scope of the presented studies included attempts to process cast magnesium alloy handles in a vibratory-abrasive smoothing machine using various types of ceramic, resin and porcelain abrasive fittings as well as their polishing and drying with granules from the corn cob in a vibratory dryer. The morphology and geometric structure of the surface of the magnesium alloy handles were measured after each step of the vibration-abrasive treatment using a microscope and an optical profilometer.

14

Effects of SPD by Biaxial Alternate Forging on the Tensile Properties and Microstructure of AZ31B Magnesium Alloy

Shin Young-Chul, Ha Seong-Ho, Shah Abdul Wahid

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 1

97--101

EN

The forming limit of AZ31 alloy, a representative Mg-Al-Zn-based wrought alloy, and the effect of severe plastic deformation (SPD) by examining the microstructure change caused by dynamic recrystallization led by high temperature and high dislocation density at 300℃ using a biaxial alternate forging (BAF) were investigated in this study. As a result of BAF test for AZ31 Mg alloy, significant cracks on the ends of workpieces occurred after 7 passes. The microstructure of as-extruded specimen showed the non-uniform distribution of the relatively coarse grains and the fine grains considered to be sub-grains. However, as the number of passes increases, the area of coarse grains gradually disappeared and the fine grains became more dominant in the microstructures. The result of tensile test for workpieces with each forging pass showed an increase in strength depending on pass number was shown with a slight increase of elongation. The Electron Backscatter Diffraction (EBSD) results exhibited that, the microstructure showed the presence of coarse grains and twins after only 1 pass, while the grains appeared to be significantly refined and uniformly distributed after 3 pass, at which the strength and elongation began to increase, simultaneously.

15

Investment Casting of AZ91 Magnesium Open-Cell Foams

Kapłon Honorata, Dmitruk Anna, Naplocha Krzysztof

Archives of Foundry Engineering

|

2023

|

Vol. 23, iss. 1

11--16

EN

The process of investment casting of AZ91 magnesium alloy open-cell porosity foams was analysed. A basic investment casting technique was modified to enable the manufacturing of magnesium foams of chosen porosities in a safe and effective way. Various casting parameters (mould temperature, metal pouring temperature, pressure during metal pouring and solidifying) were calculated and analysed to assure complete mould filling and to minimize surface reactions with mould material. The foams manufactured with this method have been tested for their mechanical strength and collapsing behaviour. The AZ91 foams acquired in this research turned out to have very high open porosity level (>80%) and performed with Young’s modulus of ~30 MPa on average. Their collapsing mechanism has turned out to be mostly brittle. Magnesium alloy foams of such morphology may find their application in fields requiring lightweight materials of high strength to density ratio or of high energy absorption properties, as well as in biomedical implants due to magnesium’s high biocompatibility and its mechanical properties similar to bone tissue.

16

Influence of Defects on Deformation Behavior of High-Pressure Die-Casting Magnesium Alloys

Braszczyńska-Malik Katarzyna

Archives of Foundry Engineering

|

2023

|

Vol. 23, iss. 2

10--14

EN

The results of investigations of defects in AME-series magnesium alloys produced by the high-pressure die-casting method are presented. The analyzed magnesium alloys contain about 5 wt% aluminum and 1-5 wt% rare earth elements introduced in the form of mischmetal. The casts were fabricated using a regular type cold-chamber high-pressure die-casting machine with a 3.2 MN locking force. The same surfaces of the casts were analyzed before and after the three-point bending test in order to determine the influence of the gas and shrinkage porosity on the deformation behavior of the alloys. The obtained results revealed that the most dangerous for the cast elements is the shrinkage porosity, especially stretched in the direction perpendicular to the that of the tensile stress action. Additionally, the influence (Mg) solid solution and its interaction on the cracking process was described [alpha]  of deformation twins arise in the dendrites of the primary.

17

Effect of number of tool shoulders on the quality of steel to magnesium alloy dissimilar friction stir welds

Khalaf Hassanein I., Al-Sabur Raheem, Derazkola Hamed Aghajani

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 2

art. no. e125, 2023

EN

Due to magnesium and iron’s immiscibility, joining magnesium alloy and steel with modern welding procedures like friction stir welding (FSW) is still complicated. Insufficient chemical bonding and mixing of raw materials in the stir zone are the main problems of joining magnesium alloy and steel. Accordingly, this paper aims to use tools with different numbers of shoulders to boost the properties of the final joint. The different tools with 1, 2, 3 and 4 shoulders were produced and used between magnesium alloy and steel during FSW. The thermal changes during the process are monitored, material flow and mechanical properties are investigated, and fractography is done on the tensile test samples. The results show that increasing shoulder numbers enhances frictional heat generation but not leads to more mechanical interlocking of base metals at interfaces. The maximum heat was generated when welded by two shoulders (600 °C), and the lowest heat was generated in one shoulder joints (540 °C). The number of shoulders for achieving the best mechanical properties has limitations. The results show that the final quality of the joint improves from one shoulder tool to three, but shows decreases at joints that were welded by more than three shoulders. The most robust tensile strength was recorded in two shoulder samples (210 MPa) with brittle fracture behavior.

18

Natryskiwane metodą APS powłoki hydroksyapatytowe do zastosowań w implantologii

Dudek Agata

Ochrona przed Korozją

|

2022

|

nr 6

182--185

PL

Ze względu na możliwe zastosowanie biodegradowalnych implantów ze stopów magnezu w ortopedii oraz w celu zwiększenia ich odporności na korozję można pokryć ich powierzchnię bioaktywnymi powłokami, np. hydroksyapatytowymi. W pracy zaproponowano wprowadzenie modyfikacji w zakresie natryskiwanych plazmowo metodą APS (atmosferic plasma spraying) powłok hydroksyapatytowych, polegającej na zastosowaniu dodatku 20% wag. ceramiki YSZ (yttria stabilized zirconia). Analizowano morfologię oraz mikrostrukturę powłok za pomocą mikroskopu cyfrowego KEYENCE VHX-7000, a także grubość – miernikiem Testan DT-20 AN 120 157 oraz skład fazowy – z użyciem dyfraktometru Seifert T-T. W celu potwierdzenia możliwości zastosowania powłok w implantologii przeprowadzono badania odporności korozyjnej w symulowanym płynie ustrojowym, odwzorowującym warunki ludzkiego organizmu.

EN

Taking into account the potential use in orthopedics and obtaining an increase in corrosion resistance of biodegradable implants made of magnesium alloys, bioactive coatings, e.g. hydroxyapatite, can be applied to their surface. In this paper, a modification of the APS (atmosferic plasma spraying) plasma spraying method was proposed for hydroxyapatite coatings by adding 20% wt. YSZ ceramics (yttria stabilized zirconia). The morphology and microstructure of the coatings were analysed using the KEYENCE VHX-7000 digital microscope, thickness using the Testan DT-20 AN 120 157 meter and phase composition using a Seifert T-T diffractometer. In order to confirm the possibility of using coatings in implantology, corrosion resistance tests were carried out in a simulated body fluid mapping the conditions of the human body.

19

Vibration analysis during AZ31 magnesium alloy milling with the use of different toolholder types

Korpysa Jarosław, Zagórski Ireneusz

Eksploatacja i Niezawodność

|

2022

|

Vol. 24, no. 3

489--501

EN

Machining vibrations are an important issue as they occur in all types of machining processes. Due to its negative impact on machining results, this phenomenon is undesirable, and so there have been continuous efforts to find solutions that will minimise it, and thus improve the stability and safety of the machining process. The paper attempts to determine the impact of toolholder type and cutting condition on the vibrations generated while milling an AZ31 magnesium alloy. The tests were performed using the three most common types of toolholders: ER, Shrink Fit and hydraulic. The vibration displacement and acceleration signals were analysed based on parameters such as Peak-to-Peak, Peak, and Root Mean Square. Composite Multiscale Entropy was also applied to check the stability of cutting processes and define the level of signal irregularity. To determine the frequencies of vibrations and to detect chatter vibrations Fast Fourier Transform was performed. This provides information on the stability and enables vibrations to be minimized by avoiding unfavourable cutting conditions.

20

Optimization of process parameters in turning of magnesium AZ91D alloy for better surface finish using genetic algorithm

Pradeep Kumar Madhesan, Venkatesan Rajamanickam, Manimurugan Manickam

Acta Innovations

|

2022

|

no. 43

54--62

EN

This research examined at the optimum cutting parameters for producing minimum surface roughness and maximum Material Removal Rate (MRR) when turning magnesium alloy AZ91D. Cutting speed (m/min), feed (mm/rev), and cut depth (mm) have all been considered in the experimental study. To find the best cutting parameters, Taguchi's technique and Response Surface Methodology (RSM), an evolutionary optimization techniques Genetic Algorithm (GA) and Non-dominated Sorting Genetic Algorithm-II (NSGA-II) were employed. GA gives better results of 34.04% lesser surface roughness and 15.2% higher MRR values when compared with Taguchi method. The most optimal values of surface roughness and MRR is received in multi objective optimization NSGA-II were 0.7341 µm and 9460 mm3/min for the cutting parameters cutting speed at 140.73m/min, feed rate at 0.06mm/min and 0.99mm depth of cut. Multi objective NSGA-II optimization provides several non-dominated points on Pareto Front model that can be utilized as decision making for choice among objectives.