Dry sliding wear of a Ni-based superalloy as a function of the aging time.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3091-3102
Author(s):  
Luis E. Gonzalez A. ◽  
Arnoldo Bedolla-Jacuinde ◽  
Eduardo Cortés C ◽  
Francisco V. Guerra ◽  
A Ruiz

AbstractFrom the present work, the wear behavior of aged Ni-based superalloy was analyzed under dry sliding conditions. Such alloy was melted in a vacuum induction furnace and cast into a ceramic mold. Then the alloy was solubilized at 1080°C for 4 hours and then aged at 760°C for 4, 8, 16, 24, 48, 72 and 150 hours. The alloy was characterized as-cast and also in the heat-treated conditions by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Mechanical characterization included just Vickers hardness and wear resistance under dry sliding conditions by a block on ring configuration according to the ASTM G77 standard. Wear tests were undertaken for 2000 m at a speed of 0.7 ms-1 at two different loads (25 and 78 N). The worn samples were analyzed by an optical profiler to determine the wear volume and by SEM to analyze the worn surface and the microstructure below the worn surface. The main findings indicate the formation of an oxide layer mainly formed by Cr and Ni during sliding. The thickness of such a layer is about 10 μm for short aging times and about 5 μm for longer aging times. For this load, the wear resistance was 50% higher for the shorter aging times than that for the longer aging times. This behavior is described in terms of the thickness of the protecting layer, and on the availability of chromium to form such a layer since it forms Cr23C6 at long aging times. On the other hand, for a load of 78 N the wear behavior is in agreement with hardness. Wear resistance increases with aging time due to the higher precipitation of prime gamma phase.

Author(s):  
UmaMaheshwera Reddy Paturi ◽  
Narala Suresh Kumar Reddy

Dry sliding experiences high friction and wear thus influencing the life and quality of the parts under sliding. To provide low friction and improve wear resistance, solid lubricants have an edge over conventional choice. This article features a specific study of the application of solid lubricant in dry sliding operations and presents its influence on wear resistance. Using a pin-on-disc tribometer designed according to ASTM G99 standard, dry sliding wear tests on aluminum alloy AA6351-T6 specimens were performed against uncoated EN31 steel and molybdenum disulphide (MoS2) coated EN31 steel discs. In this study, counter surfaces (discs) were coated with micron sized MoS2 solid lubricant powder particles using electrostatic spray coating (ESC) method. The best results for wear volume and friction coefficient (minimum values) were registered when aluminum specimen slid against MoS2 coated EN31 steel. Outcome of this study shows that the presence of solid lubricant film on disc specimen will greatly influence the sliding performance of pin material in lubricating and preventing wear through reduction in the frictional force due to presence of lamellar structure as a transfer film and favorable change in sliding interaction.


2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Prosanta Biswas ◽  
Manas Kumar Mondal ◽  
Durbadal Mandal

The microstructural morphology and wear behavior of as-cast Al–X wt% Mg2Si (X = 0.0, 5.0, 10.0, 15.0, and 20.0) composites were investigated through optical microscopy (OM), energy dispersive X-ray (EDX) spectrometry, scanning electron microscopy (SEM), and field emission scanning electron microscopy (FESEM). The dry sliding wear behavior was studied against an EN 31 hardened steel disk at four different applied loads (19.6 N, 29.4 N, 39.2 N, and 49 N) with a sliding speed of 62.8 m/min for 1 h. The optical microscopy analysis exhibits that the primary Mg2Si particles average equivalent diameter and volume fraction are increased with an increase in Mg2Si (Mg and Si) concentration in the Al–Mg2Si composite. Therefore, the bulk hardness of the composites is increased, whereas the primary Mg2Si hardness decreased because the coarser primary Mg2Si particles have less compactness. The wear resistance of the commercially pure aluminum significantly improved due to Mg2Si reinforcement, and the wear resistance is increased with the increase in Mg2Si concentration up to 15.0 wt% and then decreased at 20.0 wt%. The tested composites worn surfaces and debris exhibit adhesion, delamination, microcutting-abrasion, abrasive- and oxidation-type wear mechanism.


2011 ◽  
Vol 306-307 ◽  
pp. 425-428
Author(s):  
Jing Li ◽  
Xiao Hong Fan ◽  
De Ming Sun

Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressing. The phases and dry sliding wear behavior were studied. The results show that Fe-28Al bulk materials are mainly characterized by the low ordered B2 Fe3Al structure with some dispersed Al2O3 particles. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There are obvious differences in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys under different testing conditions. Under the load of 100N, there is plastic deformation on the worn surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows, but micro-crack and layer splitting begin to form on the surface of Fe-28Al. Under the load of 200N, serious plastic deformation and work-hardening lead to rapid crack propagation and eventually the fatigue fracture of Fe-28Al. Plastic deformation is the main wear mechanism of Fe-28Al-10Ti under the load of 200N, which are characterized by micro-crack and small splitting from the worn surface.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 296 ◽  
Author(s):  
Chao Sun ◽  
Nannan Lu ◽  
Huan Liu ◽  
Xiaojun Wang ◽  
Xiaoshi Hu ◽  
...  

In this study, the dry sliding wear behaviors of SiC particle reinforced AZ91D matrix composites fabricated by stirring casting method were systematically investigated. The SiC particles in as-cast composites exhibited typical necklace-type distribution, which caused the weak interface bonding between SiC particles and matrix in particle-segregated zones. During dry sliding at higher applied loads, SiC particles were easy to debond from the matrix, which accelerated the wear rates of the composites. While at the lower load of 10 N, the presence of SiC particles improved the wear resistance. Moreover, the necklace-type distribution became more evident with the decrease of particle sizes and the increase of SiC volume fractions. Larger particles had better interface bonding with the matrix, which could delay the transition of wear mechanism from oxidation to delamination. Therefore, composites reinforced by larger SiC particles exhibited higher wear resistance. Similarly, owing to more weak interfaces in the composites with high content of SiC particles, more severe delamination occurred and the wear resistance of the composites was impaired.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1618 ◽  
Author(s):  
Zhaohuan Song ◽  
Songhao Zhao ◽  
Tao Jiang ◽  
Junjie Sun ◽  
Yingjun Wang ◽  
...  

In this work, a multiphase microstructure consisting of nanobainte, martensite, undissolved spherical carbide, and retained blocky austenite has been prepared in an Al-alloyed high carbon steel. The effect of the amount of nanobainite on the dry sliding wear behavior of the steel is studied using a pin-on-disc tester with loads ranging from 25–75 N. The results show that, there is no significant differences in specific wear rate (SWR) for samples with various amounts of nanobainite when the normal load is 25 N. While, the SWR firstly decreases and then increases with increasing the amount of nanobainite, and the optimum wear resistance is obtained for samples with 60 vol.% nanobainite, when the applied load increases to 50 and 75 N. The improved wear resistance is attributed to the peak hardness increment resulted from the transformation of retained austenite to martensite, work hardening, along with amorphization and nanocrystallization of the worn surface. In addition, the highest toughness of the samples with 60 vol.% nanobainite is also proven to play a positive role in resisting sliding wear. EDS (energy dispersion spectrum) and XRD (X-ray diffraction) examinations reveal that the predominant failure mechanism is oxidative wear.


Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 207
Author(s):  
Eleonora Santecchia ◽  
Marcello Cabibbo ◽  
Abdel Magid Salem Hamouda ◽  
Farayi Musharavati ◽  
Anton Popelka ◽  
...  

The applications of aluminum and its alloys are still limited by low hardness and low wear resistance properties. Surface modifications, such anodizing and plasma electrolytic oxidation, represent a feasible way to overcome these drawbacks. In this study, discs of AA6082 were subjected to the so-called G.H.A. hard anodizing process leading to an anodized layer having a honeycomb-like structure. Samples having alumina layer thicknesses of 10, 50 and 100 μm were subjected to unidirectional dry sliding wear tests, using bearing steel and silicon nitride as counterbody materials. Surface and structure characterization of the samples were performed before and after the tribological tests, using a wide range of techniques; atomic force microscopy and scanning electron microscopy techniques were used before the wear tests. The wear scars were characterized by scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy techniques. Results show that the different thickness of the anodized layer does not affect the pores dimensions but has an influence on the micrometric domains in which the pores are divided. These features coupled with the wear test conditions, show to have a strong influence on the wear behavior. The thinnest sample showed also the best performance against the ceramic counterbody.


2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Hui Tan ◽  
Jun Cheng ◽  
Shuai Wang ◽  
Shengyu Zhu ◽  
Yuan Yu ◽  
...  

Wear-resistant aluminum alloys have enormous potential applications. In this paper, the Al–20Si–5Fe–2Ni alloy was fabricated by hot-pressed sintering, and its dry sliding wear behavior was investigated from 25 °C to 500 °C sliding against Al2O3 ceramic and AISI 52100 steel. The microstructure, phase, high temperature hardness, and worn surface of the sintered alloy were examined. The results indicate that the uniform distribution of Si particles and Al5FeSi intermetallic in the Al matrix contribute to its superior tribological properties. Additionally, the correlation of the tribological behavior of the alloy with the sliding testing conditions was studied, and its wear mechanism was discussed.


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Roshita David ◽  
Rupa Dasgupta ◽  
B. K. Prasad

The in situ method of making zinc-aluminum composites wherein TiC has been introduced has been investigated in the present paper for its microstructural, physical, and dry sliding wear behavior and compared with the base alloy. In the present study, ZA-27 alloy reinforced with 5 and 10 vol % TiC was taken into consideration. The results indicate that the wear rate and coefficient of friction of composites were lower than that of base alloy. The material loss in terms of both wear volume loss and wear rate increases with increase in load and sliding distance, respectively, while coefficient of friction follows a reverse trend with increase in load. Better performance was obtained for 5% TiC reinforcement than with 10% probably due to agglomeration of particles resulting in nonuniform dispersion. Worn surfaces were analyzed by scanning electron microscopy (SEM) analysis.


Author(s):  
Akshay Shinde

Abstract: To improve the wear resistance of the hybrid powder coating, TiO2 nanoparticles was hot mixed to form a homogenous mixture with the powder in the range varying wt. dry sliding wear test conducted to determine the wear resistance. The experiments were design according to Taguchi L9 array to find the optimum nanoparticles content required to minimize the wear rate of the coating. ANOVA was used to determine the effect of the parameters on wear rate. It showed that reinforcement has the maximum contribution on the wear rate of the coating as compared to load and frequency. From the graph of means optimum parametric values was obtained at 2 % wt of reinforcement, 2 N load and 2 Hz frequency. The wear rate decrease with the increase in reinforcement. Keywords: Taguchi Method, Tribometer, Hybrid powder, TiO2, Wear Rate.


2014 ◽  
Vol 592-594 ◽  
pp. 175-180 ◽  
Author(s):  
M.S. Prabhudev ◽  
Virupaxi Auradi ◽  
Karodi Venkateshwarlu ◽  
S.M. Suresha ◽  
S.A. Kori

In the present investigation, effect of minor additions of magnesium (Mg) content on the dry sliding wear behavior of A356 alloy has been reported. Alloy composition, normal pressures and sliding distances on A356 alloy has been studied. The worn surfaces were characterized by SEM microanalysis. The results indicate that, the wear rate of A356 alloy increases with increase in normal pressures and sliding distances in all the cases and decreases with 0.7% Mg addition to the A356 alloy. This is due to the change in microstructure resulting in improvement of hardness and strength of the alloy. The worn surface study indicates that, the formation of oxide layer between the mating surfaces during sliding improves sliding wear performance.


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