Optimum Load in Vickers Microhardness Testing of Treated Magnesium Alloy by Thermal Oxidation

In this study, annealed AL-6063 alloy was processed by the Equal Channel Angular Extrusion (ECAE) up to 6 passes at a temperature of 200°c following route A with a constant ram speed of 30 mm/min through a die angle of 90° between the die channels. The influence of ECAE processing on the evolution of microhardness in the material was studied using Vickers microhardness testing. The detailed analysis was carried out on the samples of as-received, one, two, three, four, five, and six pass conditions. The grain diameter reduced from 45μm to 2.8 μm after 6 passes of ECAE. The results indicated around 90% increase in Microhardness after 5 passes. Hardness of the inner surface where the billet was under compression was slightly higher than that of the mid-surface.

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Influence of number of ECAP passes on microstructure and mechanical properties of AZ31 magnesium alloy

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0077-5 ◽

2012 ◽

Vol 57 (3) ◽

pp. 711-717 ◽

Cited By ~ 7

Author(s):

K. Bryła ◽

J. Dutkiewicz ◽

L. Litynska-Dobrzynska ◽

L.L. Rokhlin ◽

P. Kurtyka

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Magnesium Alloy ◽

Grain Refinement ◽

Vickers Microhardness ◽

Az31 Alloy ◽

Az31 Magnesium Alloy ◽

Angular Pressing ◽

Microstructure And Mechanical Properties ◽

Transmission Electron

The aim of this work was to investigate the influence of the number of equal channel angular pressing (ECAP) passes on the microstructure and mechanical properties of AZ31 magnesium alloy. The microstructure after two and four passes of ECAP at 423 and 523 K was investigated by means of optical and transmission electron microscopy. The mechanical properties were carried out using Vickers microhardness measurements and compression test. The grain refinement in AZ31 alloy was obtained using ECAP routes down to 1,5 μm at 423 K. Processes of dynamic recrystallization during ECAP were observed. It was found that a gradual decrease of grain size occurs with the increasing of number of ECAP passes. The grain refinement increases mechanical properties at ambient temperature, such as Vickers microhardness and compression strength proportionally to d-0.5.

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Corrosion Resistance of Ti-6Al-4V Machined Surfaces Improved by Thermal Oxidation

Engineering Journal ◽

10.4186/ej.2020.24.5.185 ◽

2020 ◽

Vol 24 (5) ◽

pp. 185-193

Author(s):

Carolina Aurélia Ribeiro Maestro ◽

Marina Cristina Ferreira ◽

Alysson Helton Santos Bueno ◽

Artur Mariano de Sousa Malafaia

Keyword(s):

Corrosion Resistance ◽

Thermal Oxidation ◽

Body Fluid ◽

Vickers Microhardness ◽

The Other ◽

Machining Parameters ◽

Before And After ◽

Economical Process ◽

Better Than ◽

Machined Surfaces

Ti-6A-l4V alloy is widely used in implants and prosthesis applications. Although machining is a fast and economical process, the roughness generated can compromise corrosion resistance. Thus, the goal of this study was to overcome this limitation using thermal oxidation in machined surfaces. Samples with polished surfaces were used for comparison purposes. Two sets of machining parameters were used to generate different roughness, property evaluated in polished and machined samples before and after thermal oxidation. Vickers microhardness and polarization tests using simulated body fluid (SBF) were also performed. Thermal oxidation generated similar microhardness for polished and machined samples, higher than for polished and non-oxidized condition. On the other hand, oxidation increased the roughness only for polished condition. The corrosion resistance was improved in all oxidized samples, and the best result was found to the intermediate roughness (Ra = 0.76 um), in a machined sample. The results demonstrated that thermal oxidation can be used to overcome machining limitations regarding corrosion resistance, achieving behavior even better than polished samples.

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Nanoparticles as void fillers in glass ionomer cement for enhanced physicomechanical properties

Materials Express ◽

10.1166/mex.2020.1864 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1960-1964

Author(s):

Mansour K. A. Assery ◽

Abdulrahman Alshubat ◽

AlWaleed Abushanan ◽

Nawaf Labban ◽

Mohamed Hashem

Keyword(s):

Vickers Microhardness ◽

Testing Machine ◽

Glass Ionomer Cement ◽

Study Groups ◽

Control Group ◽

Glass Ionomer ◽

Universal Testing ◽

Microhardness Testing ◽

Diametral Tensile Strength ◽

Ionomer Cement

The study evaluated the addition of silver (Ag) and titanium dioxide (TiO2) nanoparticles to conventional glass ionomer cement (GIC), considering compressive strength (CS), diametral tensile strength (DTS), flexural strength (FS), and hardness. Ag and TiO2 nanoparticles were blended into the powder of a commercially available GIC restorative material at 5% (w/w). Unblended powder was used as a control. One hundred twenty samples were prepared from two study groups and one control group (n = 10). CS, DTS, and FS were evaluated using a universal testing machine, while hardness was measured by Vickers microhardness testing. The data obtained were analyzed using One-way analysis of variance and the Tukey?s test (p < 0.05). GIC containing Ag and TiO2 nanoparticles significantly improved the CS, DTS, and hardness compared to the control group (p < 0.05). However, the FS was not much affected by the addition of either of the nanoparticles (p >0.05). TiO2 blended GIC demonstrated significantly higher CS (154.20+2.38) and DTS (13.2±0.5 MPa) compared to control 117.2±1.2 MPa and 7.2 ±0.8 MPa, respectively. While Blend of GIC+Ag nanoparticles showed the highest FS (29.0±0.7 MPa). Additionally, the blend of GIC+TiO2 exhibited the highest hardness (90.4±1.1 VHN). Ag and TiO2 blended GICs might guarantee their use in occlusal or higher stress-bearing areas.

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Analysis of the Solid Solution Microstructure of (HF) Al-Zn Alloys

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.303-304.39 ◽

2010 ◽

Vol 303-304 ◽

pp. 39-53 ◽

Cited By ~ 4

Author(s):

H. Bedboudi ◽

A. Bourbia ◽

M. Draissia ◽

S. Boulkhessaim ◽

M.Y. Debili

Keyword(s):

High Frequency ◽

Vickers Microhardness ◽

Induction Melting ◽

Strengthening Mechanisms ◽

X Ray Diffraction ◽

Microstructural Characteristics ◽

X Ray ◽

Microhardness Testing ◽

Rapidly Solidified ◽

Zn Alloys

Rapidly solidified Al-Zn alloys with Zn contents ranging up to 50 wt.% were made under vacuum, by high-frequency (HF) induction melting, from compacted mixture targets of Al and Zn of fine (99.99 % purity) elemental powders. The microstructural characteristics and strengthening mechanisms were investigated. The crystallographic microstructures were characterized by means of X-ray diffraction (XRD) analyses and optical microscopy observations as well as Vickers microhardness testing. Detailed overviews of alloying solubility of zinc in aluminium were given. Extensive solid solutions of CFC Al were found in the (HF) Al-Zn alloys, and a higher Vickers microhardnesses compared to that of pure (HF) aluminium.

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Hardness Homogeneity in an AZ80 Magnesium Alloy Processed by High-Pressure Torsion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.139 ◽

2016 ◽

Vol 879 ◽

pp. 139-144

Author(s):

Saad A. Alsubaie ◽

Yi Huang ◽

Terence G. Langdon

Keyword(s):

High Pressure ◽

Magnesium Alloy ◽

Room Temperature ◽

Vickers Microhardness ◽

High Pressure Torsion ◽

Disc Diameter ◽

Az80 Magnesium Alloy

Experiments were conducted on an AZ80 magnesium alloy by processing by high-pressure torsion (HPT) at room temperature (296 K) for up to 10 turns under an imposed pressure of 6.0 GPa. Measurements of the Vickers microhardness along diameters and through the disk thicknesses were recorded after HPT to evaluate the evolution towards homogeneity. The results show hardness increases up to a factor of approximately 2 and the deformation is more homogeneous along the disc diameter than through the thickness.

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Low temperature thermal oxidation towards hafnium-coated magnesium alloy for biomedical application

Materials Letters ◽

10.1016/j.matlet.2017.01.009 ◽

2017 ◽

Vol 190 ◽

pp. 181-184 ◽

Cited By ~ 4

Author(s):

Dongfang Zhang ◽

Zhengbing Qi ◽

Binbin Wei ◽

Zhoucheng Wang

Keyword(s):

Magnesium Alloy ◽

Low Temperature ◽

Thermal Oxidation ◽

Biomedical Application

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The Effect of Microstructure and Mechanical Properties of Aluminium Aa6061 before and after Heat Treatment Using TIG

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.465-466.881 ◽

2013 ◽

Vol 465-466 ◽

pp. 881-885

Author(s):

Rosli Ahmad ◽

Samir Sani Abdulmalik

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Solution Heat Treatment ◽

Artificial Aging ◽

Vickers Microhardness ◽

Testing Machine ◽

Post Weld Heat Treatment ◽

Microstructure Characteristics ◽

Microhardness Testing ◽

Before And After

This work studies the effect of a post-weld heat treatment (PWHT) on the mechanical and microstructure properties of an AA6061 sample welded using Tungsten Inert Gas (TIG) method. TIG method is comparatively flexible and has good economy. The welded samples were divided into as-welded and PWHTs samples. The PWHTs samples were solution heat treatment, water quenching and artificial aging. Both welded samples were cut according to the ASTM E8M-04 standard to obtain the tensile strength and the elongation of the joints. The failure pattern of the tensile tested specimens was analysed using scanning electron microscopy (SEM). A Vickers microhardness testing machine was used to measure the hardness across the joints. From the results, the PWHTs were able to enhance the mechanical properties and microstructure characteristics of the AA6061 joints welded by the TIG method.

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