High-Speed Dry Tribological Behaviors of CrNiMo Steel in Nitrogen and Oxygen Atmospheres

2011 ◽  
Vol 704-705 ◽  
pp. 877-885
Author(s):  
San Ming Du ◽  
Yong Zhen Zhang ◽  
Bao Shangguan
Keyword(s):  
Abrasive Wear ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Wear Mechanisms ◽  
High Speed ◽  
Normal Load ◽  
Dry Sliding ◽  
Tribological Behaviors ◽  
Electron Dispersion ◽  
Worn Surface

Abstract: In this article, the high-speed dry sliding tribological behaviors of CrNiMo steel against brass in nitrogen and oxygen atmospheres are investigated using a pin-on-disc tribometer. The worn surface is characterized by scanning electron microscopy and electron dispersion spectrums analysis. The wear mechanisms of CrNiMo steel are also analyzed. The results indicate that the tribological properties of CrNiMo steel are coincidental with the law of dry sliding of metal, where the friction coefficients decreases with an increase in sliding speed and with normal load. However, the atmosphere has obvious effects on the tribological properties of CrNiMo steel. In the sliding process, friction heat plays an important role on the tribological properties of materials in high-speed dry friction. The high-speed wear mechanism of CrNiMo steel varies at different atmospheres. In a nitrogen atmosphere, the wear mechanism of CrNiMo steel is mainly characterized by adhesion at a lower speed and load. When the speed and load are increased, melting trace is found in the worn surface accompanied by an abrasive wear. In an oxygen atmosphere, the mechanism is characterized by adhesion at a lower speed and load; with an increase in speed and load, it gradually transformed into oxidation wear and abrasive wear. The difference of the wear mechanisms in the different atmospheres and test parameters is primarily due to the transfer films formed on the contact surfaces of the sliding pairs. In our experimental conditions, the surface film is mainly the metal film in nitrogen, whereas, it is the oxide film in oxygen.

Effect of load on the tribological properties of Si3N4-hBN composite ceramics sliding against Si3N4

2018 ◽  
Vol 70 (9) ◽  
pp. 1699-1705
Author(s):  
Dong Qiang Gao ◽  
Rui Wang ◽  
Wei Chen
Keyword(s):  
Abrasive Wear ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Water Lubrication ◽  
Content Type ◽  
Lubrication Film ◽  
Pin On Disc ◽  
Lubrication Condition ◽  
Worn Surface

Purpose The effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 were investigated under dry and water lubrication condition. Design/methodology/approach Using a MMU-5G type pin-on-disc friction and wear tester. Findings Under the dry friction, the wear mechanism was dominated by ploughing and abrasive wear, and the contact status was elastic contact under the load less than 25 N. With the increase of the load, the friction coefficient decreased; the main wear mechanism was fatigue fracture, and the contact status turned into plastic contact. Under water lubrication, effective lubrication film could be produced on the worn surface, and it had a function of fluid lubrication under the load less than 15 N. With the increase of the load, the pin and the disc came into direct contact, and the friction and wear of the pairs were aggravated; the wear mechanism changed from chemical wear into abrasive wear and brittle spalling. Originality/value The study on the effect of the load on the tribological properties of Si3N4-hBN sliding against Si3N4 was investigated under dry and water lubrication condition in the way of contact stress.

Dry Sliding Tribological Behavior of Columnar-Grained Fe2B Intermetallic Compound Under Different Loads

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Kemin Li ◽  
Zhifu Huang ◽  
Ting Min ◽  
Jiamei Liu ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Intermetallic Compound ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Laser Scanning ◽  
Tribological Behavior ◽  
Normal Load ◽  
Dry Sliding ◽  
Dynamic Friction Coefficient ◽  
Worn Surface

The dry sliding tribological behavior of a columnar-grained Fe2B intermetallic compound under different normal loads was evaluated by scanning electron microscopy (SEM), XPS, and 3D laser scanning microscope. The results indicated that under a load of 12 N, after a 35 min break-in period, the dynamic friction coefficient decreased from 0.78 to about 0.6 and this low value was maintained until the end of test. When the normal load increased from 4 N to 20 N, both the average friction coefficient and wear rate values initially decreased and then increased. The lowest values of the average friction coefficient and wear rate were obtained under a load of 12 N. As the load increased from 4 N to 12 N, a complete film formed on worn surface. Nevertheless, when the load increased to 16 N, severe self-induced vibration occurred and a corrugated ribbon appeared on the surface. Furthermore, severe damage on the worn surface was caused by cycling vibration under the 20 N load. Under 4 N and 12 N, the main wear mechanism was abrasive wear, while under a load of 20 N, fracture wear and abrasive wear were the mian wear mechanisms. The friction products were composed of B2O3, H3BO3, SiO2, and FexOy. More specifically, Fe2O3 was generated under 4 N load, Fe2O3 and Fe3O4 were produced under 12 N load, and the mixture of FeO, Fe2O3, and Fe3O4 appeared under 20 N load.

Research on Tribological Properties of Cast Iron at High-Speed Dry Sliding Condition

2014 ◽  
Vol 936 ◽  
pp. 2063-2067
Author(s):  
Chen Yue ◽  
Shang Guan Bao ◽  
Ying Yu Huang
Keyword(s):  
Cast Iron ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Tribological Properties ◽  
High Speed ◽  
Friction Material ◽  
Dry Sliding ◽  
Oxidative Wear ◽  
Wear Properties

The friction and wear properties of cast iron with different graphite morphologies and matrix microstructure were investigated at high speed dry sliding against GCr15 steel on the MMS-1G high-speed tribometer apparatus. The various wear micro-mechanisms and tribo-metallographic phases were studied by using scanning electron microscopy. The results show that as friction material, vermicular iron exhibits excellent comprehensive tribological properties. The friction coefficient of cast iron sliding against GCr15 decreases while the wear rate increases with the increase of sliding speed, friction coefficient and wear rate decline with the increase of pearlite content. Under the experimental condition, the main wear mechanisms of flake iron are abrasive wear, of vermicular iron are abrasive wear and oxidative wear and of nodular iron are oxidative wear, abrasive wear and fatigue spalling.

Tribological properties of Fe-Cr-B alloy for sliding boot in coal mining machine under dry sliding condition

2017 ◽  
Vol 69 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Hongbin Xuan ◽  
Gongjun Cui
Keyword(s):  
Coal Mining ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Normal Load ◽  
Mining Machine ◽  
Dry Sliding ◽  
Wear Resistant ◽  
Content Type ◽  
Wear Rates ◽  
1045 Steel

Purpose To improve the wear resistance of the sliding boot, the wear-resistant Fe-21 Wt.% Cr-5 Wt.% B alloy is prepared, and the wear mechanism is studied under dry sliding condition. Design/methodology/approach The anti-wear Fe-21 Wt.% Cr-5 Wt.% B alloy is prepared by powder metallurgy technique. The tribological behavior of Fe-Cr-B alloy sliding against ASTM 1045 steel pin is studied at 30-60 N and 0.03-0.12 m/s using a reciprocating pin-on-disk tribometer under dry sliding condition. Meanwhile, the ASTM 5140 and 3316 steel are studied as compared samples. Findings The friction coefficients of tested specimens increase with the increasing normal load. However, this effect is the opposite in case of different sliding speeds. The specific wear rates increase as the sliding speed and normal load increase. The Fe-Cr-B alloy shows the best tribological properties under the dry sliding condition and the wear mechanism is mainly ploughing. Originality/value This wear-resistant Fe-21 Wt.% Cr-5 Wt.% B alloy can replace the traditional materials to process the sliding shoes and improve the service life of coal mining machine.

WEAR MECHANISM MAP OF MAGNESIUM ALLOY COATED WITH WC/CU ELECTRODE USING ELECTRO DISCHARGE ALLOYING

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Elaiyarasan U ◽  
Satheeshkumar V ◽  
Senthilkumar C
Keyword(s):  
Magnesium Alloy ◽  
Wear Mechanism ◽  
Normal Load ◽  
Dry Sliding ◽  
Sliding Speed ◽  
Severe Wear ◽  
Mild Wear ◽  
Pin On Disc ◽  
Wear Mechanism Map ◽  
Worn Surface

The objective of this research is to study the wear mechanism of ZE41A magnesium alloy coated with WC/Cu material using EDC (Electro discharge coating). Dry sliding experiments were conducted with pin on disc method with different sliding condition such as normal load (1.5 kg - 3.5 kg), sliding speed (100rpm - 300 rpm) and sliding time (3min - 7min). Wear mechanism map was drawn against sliding condition of normal load and sliding speed which has been utilized to study the dominance of particular wear mechanism that dominates a particular wear regime. Different wear regime such as mild wear, severe wear ultra severe wear was developed by adjustment of contour line of the wear rate map. Various mechanisms such as abrasion, oxidation, delamination, plastic deformation and melting were observed in the worn surface

scholarly journals Effect of High−Speed Powder Feeding on Microstructure and Tribological Properties of Fe−Based Coatings by Laser Cladding

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1456
Author(s):  
Qiang Wang ◽  
Runling Qian ◽  
Ju Yang ◽  
Wenjuan Niu ◽  
Liucheng Zhou ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
High Speed ◽  
High Efficiency ◽  
Adhesive Wear ◽  
Steel Substrate ◽  
Powder Materials ◽  
Powder Feeding

In order to improve the wear resistance of 27SiMn steel substrate, Fe−based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high−speed powder feeding (HF) process was used to prepare Fe−based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X−ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe−based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high−speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high−efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.

Dry sliding tribological properties of PI/UHMWPE blends for high speed application

2020 ◽  
Vol 146 ◽  
pp. 106262 ◽  
Author(s):  
Song Chen ◽  
Lei Wei ◽  
Bingxue Cheng ◽  
Yongliang Jin ◽  
Chao Li ◽  
...  
Keyword(s):  
Tribological Properties ◽  
High Speed ◽  
Dry Sliding

scholarly journals Investigation on Speed-Load Sensitivity to Tribological Properties of Copper Metal Matrix Composites for Braking Application

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 889
Author(s):  
Yelong Xiao ◽  
Pingping Yao ◽  
Haibin Zhou ◽  
Zhongyi Zhang ◽  
Taimin Gong ◽  
...  
Keyword(s):  
Wear Rate ◽  
Metal Matrix Composites ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Normal Load ◽  
Matrix Composites ◽  
Copper Metal ◽  
Video Microscope ◽  
Speed Up ◽  
Worn Surface

A sensitivity analysis of braking speed and normal load on tribological properties of copper metal matrix composites (Cu-MMCs) was investigated using a subscale dynamometer. The morphologies of the worn surface and subsurface were observed by a scanning electron microscope and 3D video microscope. The results indicated that temperatures on the Cu-MMC surface increased with increasing the braking speed and normal load. The average coefficient of friction gradually decreased as the braking speed or normal load increased, and a slight decrease in the wear rate with increasing the braking speed up to 17 m/s after which a clear increasing trend was observed. As the normal load increased from 612 N to 1836 N, the wear rate decreased firstly and then promptly decreased. The transition in wear mechanism of Cu-MMC significantly depended on braking speed and normal load.

scholarly journals Microparticle composites on the basis of scrap utilizable in the field of agricultural production

2016 ◽  
Vol 61 (No. 2) ◽  
pp. 92-97
Author(s):  
P. Valášek ◽  
M. Brožek
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Epoxy Resin ◽  
Tribological Properties ◽  
Agricultural Production ◽  
Abrasive Wear Resistance ◽  
Considerable Decrease ◽  
Ferrous Metals ◽  
Exponential Increase ◽  
Worn Surface

For renovation of functional surfaces of machines and devices for agricultural production it is possible to use, in addition to conventionally used methods, polymers with fillers – composites. The presence of microparticles in the polymeric matrix improves substantially the abrasive wear resistance and hardness. This contribution describes tribological properties of epoxy resin filled with chips of ferrous metals – the change of volume losses increase in dependence on the pressure increase (load) having effect on the worn surface. From the carried out experiments the considerable decrease of filled resin losses is evident compared with the resin without filler. At the same time the exponential increase of volume losses with the increased load was quantified in the course of tribological tests.

INVESTIGATION ON DRY SLIDING WEAR BEHAVIOR OF TITANIUM DIOXIDE-REINFORCED MAGNESIUM MATRIX COMPOSITE

2021 ◽  
pp. 2150106
Author(s):  
P. C. ELUMALAI ◽  
R. GANESH
Keyword(s):  
Titanium Dioxide ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Wear Mechanisms ◽  
Sliding Wear ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
Significant Change

In this work, the dry sliding wear behaviors of pure monolithic magnesium and magnesium–titanium dioxide (Mg–TiO2) composites were studied using pin-on-disc tribometer against an oil-hardened nonshrinking die steel (OHNS) counter-disc with a normal load of 0.5–2[Formula: see text]kg and a sliding velocity of 1.5–2.5[Formula: see text][Formula: see text] with the sliding distance and wear track diameter of 1500[Formula: see text]m and 90[Formula: see text]mm, respectively. The pin samples were characterized for their microstructural, nanomechanical and tribological properties such as wear rate, coefficient of friction and wear fractographs. Scanning electron microscopy (SEM) was used to analyze the worn-out surfaces of each pin sample in order to identify the different types of wear and wear mechanisms and the chemical constituents of each element were quantified by energy-dispersive spectroscopy. The influence of TiO2 reinforcements on the nanomechanical behavior was studied by nanoindentation technique. As compared with pure Mg, the nanoindentation strengths of Mg–1.5TiO2, Mg–2.5TiO2 and Mg–5TiO2 composites were found to increase by 11.9%, 22.2% and 35.8%, respectively, which was due to the addition of TiO2 particles and also due to the good bonding at the interface of TiO2 and magnesium particles. From the wear test results, a significant change in wear rate was observed with the change in normal load than that of sliding speed, whereas a significant change in coefficient of friction was noticed with the changes in both normal load and sliding velocity. The dominant wear mechanisms involved under the testing conditions were identified through plotting the contour maps and SEM fractographs. Also, from the fractographs it was noticed that delamination and plowing effect have been the significant wear mechanisms observed during low wear rate of samples, whereas melting, delamination and oxidation wear have been observed during high wear rate of pure Mg and its composites.

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