scholarly journals Investigation of the Wear Behavior of Surface Welding AZ91 and AZ91+Gd Alloys under Variable Loading Conditions

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 554
Author(s):  
Qingqiang Chen ◽  
Yalei Yu ◽  
Jie Sun ◽  
Cainian Jing ◽  
Yanhua Zhao ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Wear Rate ◽  
Wear Mechanism ◽  
Sliding Friction ◽  
Wear Behavior ◽  
Az91 Alloy ◽  
Severe Wear ◽  
Surface Welding ◽  
Wear Transition

Adding rare earth elements to magnesium alloys is an effective way to improve their wear resistance. However, the effect achieved is closely related to the friction condition. In this paper, two different types of welding wires, AZ91 magnesium alloy and AZ91 + gadolinium (Gd), were used for surface welding. Dry sliding friction and wear experiments were performed on the surfacing alloys using the pin-on-disc test. The effects of Gd addition on the wear resistance and wear mechanism of the alloy were systematically studied under low to high loads. The results show that as the load increases, the friction coefficient of the surfacing AZ91 alloy gradually decreases as the wear rate increases. A mild–severe wear transition occurred at 100 N. The addition of Gd only slightly increased the wear rate under a load of 15 N. The wear rate was significantly decreased with loads in the range of 30 to 100 N and mild–severe wear transition was avoided. The influence of both Gd addition and load on the wear mechanism were considered. The overall wear resistance of the surfacing magnesium alloy was determined.

Wear Behavior and Microstructural Evolution during Dry Sliding Wear of AZ51 Magnesium Alloy

2014 ◽  
Vol 1061-1062 ◽  
pp. 674-678
Author(s):  
Yuan Bo Wang ◽  
Teng Fei Su ◽  
Ming Liang Yin ◽  
Xue Han ◽  
Xin Ying Li ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Microstructural Evolution ◽  
Wear Behavior ◽  
Thermal Softening ◽  
Surface Melting ◽  
Dry Sliding Wear ◽  
Near Surface ◽  
Severe Wear ◽  
Wear Transition ◽  
Subsurface Microstructure

Wear behavior of AZ51 magnesium alloy was studied using a pin-on-disc type wear apparatus at 20-360 N and 0.785 m/s. Wear mechanisms were determined using scanning electron microscope (SEM), including abrasion, oxidation, delamination, thermal softening and surface melting. Microstructural evolution, plastic deformation and microhardness in the subsurfaces were examined with optical microscope and hardness tester before and after mild to severe wear transition. The subsurface microstructure experienced deformation, dynamic recrystallization (DRX) and surface melting successively with increasing load. These changes in subsurface microstructure result in strain hardening and thermally-activated softening in the near-surface layers. The thermal softening originating from DRX and surface melting in subsurface is responsible for the mild to severe wear transition.

scholarly journals Masking Effect of LPSO Structure Phase on Wear Transition in Mg97Zn1Y2 Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1857
Author(s):  
Fujun Tao ◽  
Hongfei Duan ◽  
Lijun Zhao ◽  
Jian An
Keyword(s):  
Wear Rate ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Testing Machine ◽  
Masking Effect ◽  
Enhancement Effect ◽  
Severe Wear ◽  
Lpso Structure ◽  
Structure Phase ◽  
Wear Transition

Room- and elevated-temperature wear tests were conducted using a pin-on-disk testing machine to study wear behavior of Mg97Zn1Y2 alloy and role of long-period-stacking-ordered (LPSO) structure phase in mild–severe wear transition (SWT). Variation of wear rate exhibited a three-stage characteristic with load at various test temperatures, i.e., a gradual increasing stage, a slightly higher plateau stage, and a rapid rising stage. The wear mechanisms in the three stages were identified using scanning electron microscope (SEM), from which the first stage was confirmed as mild wear, and the other two stages were verified as severe wear. The interdendritic LPSO structure phase was elongated into strips along the sliding direction with Mg matrix deformation in the subsurface, plate-like LPSO structure phase precipitated at elevated temperatures of 150 and 200 °C. The fiber enhancement effect and precipitation effect of LPSO structure phase resulted in a little difference in wear rate between the first and second stages, i.e., a masking effect on SWT. Microstructure and microhardness were examined in the subsurfaces, from which the mechanism for SWT was confirmed to be dynamic recrystallization (DRX) softening. There is an apparently linear correlation between the critical load for SWT and test temperature, indicating that SWT is governed by a common critical DRX temperature.

The Effect on the Dry Sliding Wear Behavior of Gravity Cast A357 Reinforced with Dual Size Silicon Carbide Particles

2016 ◽  
Vol 829 ◽  
pp. 83-89 ◽  
Author(s):  
L. Avinash ◽  
T. Ramprabhu ◽  
Srikanth Bontha
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Transition Period ◽  
Wear Behavior ◽  
Cast Alloy ◽  
Dry Sliding Wear ◽  
Wear Loss ◽  
A357 Alloy ◽  
Severe Wear ◽  
Sliding Distance

In the present study, the composites of A357 (Al-7%Si) alloy reinforced with the bimodal sizes (~250µm (L) and ~38 µm (S)) of 6wt% SiCp and the A357 alloy were prepared by permanent mould die casting. Three different combinations of bimodal distributions were considered: (3% L + 3% S, 4% L + 2% S, and 2% L + 4% S). The wear behavior of the alloy and the composites was studied for the speed of 1 m/s and load conditions of 10-30 N with an interval of 5 N in a pin on disc apparatus. The hardness and microstructure of the composites were also characteristised. The results suggest that the addition of bimodal size of particles significantly improves the hardness and wear resistance of the alloy. Among the different combinations, the 4% L + 2% S bimodal distribution combination provides the highest wear resistance and the hardness. This result indicates that the higher amount of large size particles are more important than that of small size particles to improve the wear resistance, which implies that the particle decohesion is the rate controlling step in the present investigation. The wear rate increases with an increase of load and sliding distance. The critical load to enter into the severe wear regime for the alloy and composites is 25 N. The rapid wear loss begins above 1500 m sliding distance in the composites and the as cast alloy. The wear rate curve with respect to the sliding distance shows three regimes (1) transition period (2) steady state (3) severe wear state. The wear morphology studies show that the abrasive wear is the main wear mechanism in the bimodal size composites whereas the delamination wear is predominant in the alloy.

Wear Behavior of WC–Cu Deposited ZE41A Magnesium Alloy Using Wear Mechanism Map

2020 ◽  
Vol 12 (8) ◽  
pp. 1028-1033
Author(s):  
U. Elaiyarasan ◽  
V. Satheeshkumar ◽  
C. Senthilkumar
Keyword(s):  
Magnesium Alloy ◽  
Wear Rate ◽  
Wear Mechanism ◽  
Wear Behavior ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Sliding Speed ◽  
Pin On Disc ◽  
Wear Mechanism Map ◽  
Wear Modes

The present investigation studied the dry sliding wear behavior of WC–Cu deposited ZE41A magnesium alloy under various parameters such as normal load, sliding speed and sliding time and the responses are wear rate and coefficient of friction. In this investigation, WC–Cu deposited magnesium alloy specimens were tested using pin on disc apparatus against EN31 steel disc. Wear mechanism map is developed for wear rate of the deposited magnesium alloy against normal load and sliding speed to identify the different wear modes such as mild, severe and ultra sever wear. Worn surface samples is assessed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS) to confirm the different wear mechanism such as abrasion, oxidation, delamination and melting. Normal load is identified as the most dominant process parameter in this experiment. Magnesium alloy deposited using WC–Cu composite coating by EDC improved the wear behavior in the lower ranges of sliding conditions.

Effect Multiple Addition (TiO2 and Fly Ash) on Wear Behavior and Hardness of 2024 Al Alloy

2021 ◽  
Vol 1039 ◽  
pp. 201-208
Author(s):  
Ruaa A. Salman ◽  
Naser K. Zedin
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Wear Rate ◽  
Wear Behavior ◽  
Weight Percent ◽  
Al Alloy ◽  
Sliding Speed ◽  
Multiple Addition

This research is devoted to study the effect of addition (2%) TiO2 with different weight percent of fly ash particulate (0, 2, 4, 6%) to 2024 Al alloy on the wear behavior and hardness. The alloy was fabricated by the liquid metallurgy method. The results founds that the wear rate decreased from 0.55 with 0% fly ash to 0.18 at addition percentage of 6% fly ash. Also, the results reveal increasing the samples wear rate with increasing the load and loaded time. The rate of wear was decreased with increasing the sliding speed. Also, the values of hardness increased from 120VH to 160VH with rising the fly ash from 0% to 6%. Keywords: Fly Ash addition, TiO2, 2024 Al Alloy, Wear Resistance, Hardness.

Investigation of the Wear Behavior of AA6082 Against Different Counterparts

2021 ◽  
Author(s):  
Safiye İpek Ayvaz ◽  
Mehmet Ayvaz
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Behavior ◽  
Specific Wear Rate ◽  
Pin On Disk ◽  
Disk Method ◽  
Sliding Distance ◽  
Oxidation Wear

In this study, the effect of different counterparts on the wear resistance of AA6082 aluminum alloy was investigated. In tests using pin-on-disk method, 6 mm diameter Al2O3, 100Cr6 and WC-6Co balls were used as counterparts. The tests were carried out using 500 m sliding distance and 5N load. The lowest specific wear rate was measured as 7.58x10-4 mm3/Nm in WC-6Co / AA6082 couple, and the highest value was measured as 9.71x10-4 mm3/Nm in 100Cr6/AA6082 couple. In the Al2O3/AA6082 couple, the specific wear rate of the AA6082-T6 sample was determined as 8.23x10-4 mm3/Nm.While it was observed that the dominant wear type in the 100Cr6/AA6082 pair was abrasive wear, oxidation wear and oxide tribofilm were detected in the WC-6Co/AA6082 and Al2O3/AA6082 couple besides the abrasive wear.

scholarly journals Enhanced Tribological Properties of LA43M Magnesium Alloy by Ni60 Coating via Ultra-High-Speed Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 638 ◽  
Author(s):  
Osama Asghar ◽  
Lou Li-Yan ◽  
Muhammad Yasir ◽  
Li Chang-Jiu ◽  
Li Cheng-Xin
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Wear Mechanism ◽  
High Speed ◽  
Surface Engineering ◽  
Energy Dispersive Spectrometer ◽  
Wear Loss ◽  
Cross Sectional ◽  
Ultra High Speed

Laser modification techniques have been widely adopted in the field of surface engineering. Among these modified techniques, ultra-high-speed laser cladding is trending most nowadays to fabricate wear-resistant surfaces. The main purpose of this research is to provide a detailed insight of ultra-high-speed laser cladding of hard Ni60 alloy on LA43M magnesium alloy to enhance its surface mechanical properties. Multiple processing parameters were investigated to obtain the optimal result. The synthesized coating was studied microstructurally by field emission scanning electron microscopy (FESEM) equipped with an energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The microhardness and wear resistance of the Ni60 coating were analyzed under Vickers hardness and pin on disc tribometer respectively. The obtained results show that the dense Ni60 coating was fabricated with a thickness of 300 μm. No cracks and porosities were detected in cross-sectional morphology. The Ni60 coating was mainly composed of γ-Ni and hard phases (chromium carbides and borides). The average microhardness of coating was recorded as 948 HV0.3, which is approximately eight times higher than that of the substrate. Meanwhile, the Ni60 coating exhibited better wear resistance than the substrate, which was validated upon the wear loss and wear mechanism. The wear loss recorded for the substrate was 6.5 times higher than that of the coating. The main wear mechanism in the Ni60 coating was adhesive while the substrate showed abrasive characteristics.

scholarly journals Dry Sliding Wear Behavior and Mild–Severe Wear Transition of Mg97Zn1Y2 Alloy at Elevated Temperatures

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1735 ◽  
Author(s):  
Liang Li ◽  
Jihe Feng ◽  
Ce Liang ◽  
Jian An
Keyword(s):  
Test Temperature ◽  
Sliding Wear ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Hardness Measurement ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Softening Effect ◽  
Severe Wear ◽  
Wear Transition

Dry sliding wear behavior of Mg97Zn1Y2 alloy was investigated at test temperatures of 50–200 °C under three sliding speeds of 0.8 m/s, 3.0 m/s and 4.0 m/s. The wear mechanisms in mild and severe wear regimes were identified by examination of morphologies and compositions of worn surfaces using scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS), and from which wear transition maps under different sliding speeds were constructed on rectangular coordinate systems with applied load versus test temperature axes. It is found that under each sliding speed condition, mild–severe transition load decreases almost linearly within the test temperature range of 50 °C to 200 °C. Microstructure observation and hardness measurement in subsurfaces identify that the softening effect generating form dynamic crystallization (DRX) is the dominant mechanism for the mild–severe wear transition at elevated temperatures. The mild–severe wear transition at 50–200 °C follows the contact surface DRX temperature criterion, and the transition loads can be well evaluated using the criterion.

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