WEAR RESISTANCE OF AZ91D MAGNESIUM ALLOY WITH AND WITHOUT MICROARC OXIDATION COATING AND Ti6Al4V ALLOY IN ARTIFICIAL SALIVA

2009 ◽  
Vol 16 (06) ◽  
pp. 821-830 ◽  
Author(s):  
X. P. ZHANG ◽  
Y. S. ZOU ◽  
F. M. WU ◽  
Z. P. ZHAO ◽  
L. YOU ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Wear Mechanisms ◽  
Room Temperature ◽  
Artificial Saliva ◽  
Microarc Oxidation ◽  
Alloy Sample ◽  
Az91d Alloy ◽  
Oxidation Treatment ◽  
Az91d Magnesium Alloy

The wear resistances of AZ91D magnesium alloy with and without microarc oxidation (MAO) coating and Ti 6 Al 4 V alloy in artificial saliva were investigated at room temperature. The wear resistance of AZ91D magnesium alloy in artificial saliva was significantly improved after microarc oxidation treatment. The volume loss of untreated AZ91D magnesium alloy sample was 20.95 times of that of AZ91D magnesium alloy with MAO coating, and that of Ti 6 Al 4 V was 5.42 times of that of MAO. Furthermore, the wear resistance of AZ91D magnesium alloy was lower than that of Ti 6 Al 4 V alloy in artificial saliva. The wear mechanisms of AZ91D magnesium and Ti 6 Al 4 V were discussed. It was found that the wear mechanism of the MAO was associated with abrasion and microfracture. There were two dominative wear mechanisms for AZ91D alloy and Ti 6 Al 4 V alloy under the loading conditions used in the experiment, namely, micro-machining wear and deformation-induced wear.

Tribological and ageing behavior of Az91D magnesium alloy fortified with nano lanthanum and nanoceria by stir casting for aviation application

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Fahad ◽  
Bavanish B.
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Magnesium Alloy ◽  
Cerium Oxide ◽  
Stir Casting ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Az91d Alloy ◽  
Content Type ◽  
Az91d Magnesium Alloy

Purpose The aviation field requires a material with the ability to withstand severe environmental conditions. The purpose of this paper is to provide higher wear resistance and improve the lifetime of aircraft. Hence, it is vital to enhance the wear resistance and strength of the material. Design/methodology/approach In this investigation, the Az91D magnesium alloy was reinforced with lanthanum (La2O3) and cerium oxide (CeO2) nanoparticles by stir casting and heat treatment process and the tribological and mechanical properties were analyzed. Findings The results showed the Az91D/CeO2 composite exhibited higher density (1.96 g/cm3) and lower porosity (1.01%) compared to other materials due to the diffusion of CeO2 nanoparticles in between the atoms of Az91D alloy. The hardness of Az91D/ CeO2 & Az91D/ La2O3 was improved by 38% and 34%, respectively, compared to Az91D alloy owing to the reinforcing effect of hard nanoparticles. Further, the inclusion of nanoparticles decreased the mass loss and showed lower wear rate compared to the Az91D alloy due to the pinning effect of nanoparticles. In addition, the friction coefficient was observed in the order of Az91D > Az91D/ La2O3 > Az91D/ CeO2. Moreover, the heat treatment displayed positive results on the properties of all the materials. Originality/value This work is original as the combination of cerium oxide nanoparticles with Az91D magnesium alloy is not tried by earlier investigators. Further, the comparative performance of both lanthanum and cerium oxide nanoparticles on the tribological and mechanical behavior of Az91D alloy has been analyzed for aviation application. This study will provide new information to the scientific world to increase the lifetime of aviation structures.

Effect of Deformation on the Damping Capacity of Magnesium Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 737-740 ◽  
Author(s):  
Xiao Shi Hu ◽  
Kun Wu ◽  
Ming Yi Zheng ◽  
Shi Wei Xu ◽  
Y.K. Zhang
Keyword(s):  
Magnesium Alloy ◽  
Temperature Dependence ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Equal Channel Angular Extrusion ◽  
Damping Capacity ◽  
Amplitude Dependence ◽  
Az91d Alloy ◽  
Dynamic Mechanical Analyzer ◽  
Az91d Magnesium Alloy

Equal channel angular extrusion (ECAE) was applied to an as-cast AZ91D magnesium alloy. The strain amplitude dependence and temperature dependence of damping capacities of the as-cast and ECAE processed AZ91D alloys were investigated by dynamic mechanical analyzer (DMA). Microstructures of AZ91D alloys after ECAE were observed by optical microscopy (OM). In higher strain region, the damping value of 4-pass ECAE deformed AZ91D alloy was the highest among all the AZ91D alloys under different conditions. The damping peaks of ECAE deformed AZ91D alloys detected during heating from room temperature to 400°C were considered to be related to the migration of grain boundaries and the movement of dislocations during recrystallization.

Room Temperature Screw Form Rolling of AZ91D Magnesium Alloy through Processing by Extrusion-Torsion Simultaneous Working

2014 ◽  
Vol 783-786 ◽  
pp. 375-379
Author(s):  
Mitsuaki Furui ◽  
Shouyou Sakashita ◽  
Kazuya Shimojima ◽  
Tetsuo Aida ◽  
Kiyoshi Terayama ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Hardness Measurement ◽  
Rolling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Az91d Magnesium Alloy ◽  
Microstructure Observation ◽  
Fine Grain ◽  
Simultaneous Processing

Extrusion-torsion simultaneous processing is a very attractive technique for fabricating a rod-shape material with fine grain and random texture. We have proposed a new screw form rolling process combined with preliminary extrusion-torsion simultaneous working. Microstructure evolution and mechanical property change of AZ91D magnesium alloy during extrusion-torsion simultaneous processing was examined through microstructure observation, X-ray diffraction analysis and micro-Vickers hardness measurement. By the addition of torsion, the crystal orientation of AZ91D magnesium alloy workpiece was drastically changed from basal crystalline orientation to the random orientation. Crystal grain occurred through the dynamic recrystallization and tended to coarsen with an increase of extrusion-torsion temperature. Grain refinement under 2 um was achieved at the lowest extrusion-torsion temperature of 523 K. M8 gauge AZ91D magnesium alloy screw was successfully formed at room temperature using the extrusion-twisted workpiece preliminary solution treating at 678 K for 345.6 ks. It was found that the extrusion-torsion temperature of 678 K must be selected to fabricate the good screw without any defects.

Tribological behavior of AZ91D magnesium alloy composite: effect of hybrid WC – SiO2 nanoparticles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed Fahad ◽  
Bavanish B.
Keyword(s):  
Magnesium Alloy ◽  
Wear Rate ◽  
Az91d Alloy ◽  
Hybrid Particles ◽  
Wear Properties ◽  
Sliding Speed ◽  
Composite Effect ◽  
Content Type ◽  
Climate Conditions ◽  
Az91d Magnesium Alloy

Purpose Aviation field requires a material with greater tribological characteristics to withstand the critical climate conditions. Hence, it is of paramount importance to enhance the wear resistance of material. AZ91D magnesium alloy is a light weight material used in the aviation field for the construction work. The purpose of this study is to augment the wear properties of AZ91D alloy by reinforcing with hard particles such as tungsten carbide (WC) and silicon dioxide (SiO2). Design/methodology/approach In this work, three types of composites were fabricated, namely, AZ91D – WC, AZ91D – SiO2 and AZ91D – (WC + SiO2) by ball milling method, and the tribological properties were analyzed using pin-on-disc apparatus. Findings Results showed that the hardness of AZ91D alloy was greatly improved due to the reinforcing effects of WC and SiO2 particles. Wear study showed that wear rate of AZ91D alloy and its composites increased with the increase of applied load due to ploughing effect and decreased with the increase of sliding speed owing to the formation of lubricating tribolayer. Further, the AZ91D – (WC + SiO2) composite exhibited the lower wear rate of 0.0017 mm3/m and minimum coefficient of friction of 0.33 at a load of 10 N and a sliding speed of 150 mm/s due to the inclusion of hybrid WC and SiO2 particles. Hence, the proposed AZ91D – (WC + SiO2) composite could be a suitable candidate to be used in the aviation applications. Originality/value This work is original which deals with the effect of hybrid particles, i.e. WC and SiO2 on the wear performance of the AZ91D magnesium alloy composites. The literature review showed that none of the studies focused on the reinforcement of AZ91D alloy by the combination of carbide and metal oxide particles as used in this investigation.

Aging Property of AZ91D Magnesium Alloy Screw Thread-Rolled at Room Temperature Using Extrusion-Torsion Simultaneous Processing

2016 ◽  
Vol 879 ◽  
pp. 2450-2455
Author(s):  
Mitsuaki Furui ◽  
Shouyou Sakashita ◽  
Shougo Suzuki ◽  
Tetsuo Aida ◽  
Yuusuke Ishisaka ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Aging Treatment ◽  
High Strength ◽  
Extrusion Process ◽  
Peak Hardness ◽  
Screw Thread ◽  
Az91d Magnesium Alloy ◽  
Simultaneous Processing ◽  
Aging Property

We have proposed a new extrusion process functionally combined with torsion. Extrusion-torsion simultaneous processing is a very attractive technique for fabricating a rod-shape material with high strength and excellent workability. To improve the hardness, the aging treatment was performed with AZ91D magnesium alloy screw thread-rolled at room temperature using extrusion-torsion simultaneous processing. The distribution of hardness from the tip to center in as thread-rolled screw was modified to uniform distribution by the isothermal aging treatment at 423 K for 460.8 ks. The peak hardness was not depended on the working temperature and rotation speed during extrusion-torsion simultaneous processing. β-Mg17Al12 precipitates are obviously grown in as peak-aged condition comparing with as thread-rolled condition.

Corrosion Resistance of the Ceramic Coating Formed by Micro-Plasma Arc Oxidation on AZ91D Alloy

2007 ◽  
Vol 336-338 ◽  
pp. 2451-2453
Author(s):  
Shu Hua Li ◽  
Fu Chi Wang
Keyword(s):  
Magnesium Alloy ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Az91d Alloy ◽  
Plasma Arc ◽  
X Ray Diffraction ◽  
Compact Layer ◽  
Az91d Magnesium Alloy ◽  
Loose Layer ◽  
Salt Fog

The ceramic coating was formed by micro-plasma arc oxidation (MPAO) on AZ91D magnesium alloy. The surface and section morphology of coatings were observed using scanning electron microscopy. The phase composition of coatings was analyzed by X-ray diffraction. The method of salt fog experimental was carried out to proof-test performances of anti-corrosion of material. The results showed that the ceramic coating was composed by loose layer and compact layer. The coating surface has a large number of grains with various sizes. In addition, there is also a lot of pore in the loose layer, but the compact layer is tighter than the loose layer. Compact layer has a good combination with substrate magnesium alloy. The MPAO coating is mainly composed of silica oxide (MgAl2Si3O12 and β-Mg2SiO4 and (Mg4Al14) (Al4Si2)O20) and composite oxide of Mg and Al (δ-MgAl28O4). The performance of resistant corrosion of AZ91D coved by ceramic coating is higher than AZ91D magnesium alloy. The corrosion ratio of AZ91D alloy coved by ceramic coatings to AZ91D alloy is 1:8.61.

scholarly journals Wear and Corrosion Resistance of Al0.5CoCrCuFeNi High-Entropy Alloy Coating Deposited on AZ91D Magnesium Alloy by Laser Cladding

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 915 ◽  
Author(s):  
Kaijin Huang ◽  
Lin Chen ◽  
Xin Lin ◽  
Haisong Huang ◽  
Shihao Tang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Alloy Coating ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Az91d Magnesium Alloy ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance

In order to improve the wear and corrosion resistance of an AZ91D magnesium alloy substrate, an Al0.5CoCrCuFeNi high-entropy alloy coating was successfully prepared on an AZ91D magnesium alloy surface by laser cladding using mixed elemental powders. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction were used to characterize the microstructure of the coating. The wear resistance and corrosion resistance of the coating were evaluated by dry sliding wear and potentiodynamic polarization curve test methods, respectively. The results show that the coating was composed of a simple FCC solid solution phase with a microhardness about 3.7 times higher than that of the AZ91D matrix and even higher than that of the same high-entropy alloy prepared by an arc melting method. The coating had better wear resistance than the AZ91D matrix, and the wear rate was about 2.5 times lower than that of the AZ91D matrix. Moreover, the main wear mechanisms of the coating and the AZ91D matrix were different. The former was abrasive wear and the latter was adhesive wear. The corrosion resistance of the coating was also better than that of the AZ91D matrix because the corrosion potential of the former was more positive and the corrosion current was smaller.

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