scholarly journals Adhesive wear mechanism under combined electric diamond grinding

2017 ◽  
Vol 129 ◽  
pp. 01002 ◽  
Author(s):  
Vyacheslav Popov ◽  
Pavel Arkhipov ◽  
Daniel Rychkov
Keyword(s):  
Wear Mechanism ◽  
Adhesive Wear ◽  
Diamond Grinding

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.

Influence of Neodymium on Wear Resistance of Hypereutectic Al-Si Alloy

2015 ◽  
Vol 1095 ◽  
pp. 135-139
Author(s):  
Wei Xi Shi ◽  
Cheng Wu Du ◽  
Gui Mao Li ◽  
Zhi Ming Liu
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Adhesive Wear ◽  
Primary Silicon ◽  
Oxidative Wear ◽  
Initial Sample ◽  
Unmodified Alloy ◽  
Resistance Tests

The morphology of eutectic and primary silicon phases was analyzed by OM and SEM. OM and SEM results show that pure Nd can significantly refine both eutectic and primary silicon of hypereutectic Al-20%Si alloy. Morphology of primary silicon is transformed from star-shaped and irregular morphology to fine polyhedral and grain size of primary silicon is refined from 80~120 μm to 20~50 μm. Friction and wear resistance tests show that friction coefficient of Al-20%Si alloy reduces after Nd modification. Wear resistance of Al-20%Si alloy after modification is significantly improved as compared to the initial sample. The dominant wear mechanism for 0.3% Nd modified alloy is abrasive wear, adhesive wear and oxidative wear mechanism, but wear mechanism for unmodified alloy is abrasive wear and adhesive wear mechanism.

scholarly journals High Temperature Tribological Behavior of Borocarburized Layer on Q235 Steel

2021 ◽  
Vol 27 (1) ◽  
pp. 42-49
Author(s):  
Zhengang YANG ◽  
Wenping LIANG ◽  
Yanlin JIA ◽  
Qiang MIAO ◽  
Zheng DING ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Carbon Steel ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Low Carbon Steel ◽  
Boride Layer ◽  
Low Carbon ◽  
Fatigue Wear ◽  
Carburized Layer

A borocarburized layer was successfully fabricated on the surface of Q235 low-carbon steel via double glow treatment to improve the wear resistance at elevated temperature. The phase composition and microstructure of borocarburized layer were investigated by XRD and SEM. The microhardness of borocarburized layer from the surface to the substrate were detected. And the tribological behaviors of borocarburized layer and substrate were investigated under the dry-sliding against ZrO2 ball at three temperatures. The results indicate that the borocarburized layer consists of an outermost boride layer and a transition layer of carburized layer. The boride layer with main phase of Fe2B has a high hardness around 1700 HV, and the hardness of transition layer with main phase of Fe5C3 is around 600 HV. The novel gradient structure of an outermost boride layer and inner carburized layer is design in this research decreases the hardness mismatch of coating to prevent the boride layer peeling off. The friction coefficient and specific wear rate of borocarburized layer are much lower than that of substrate at the same temperature. In addition, the wear mechanism of substrate is mainly fatigue wear and slightly adhesive wear at 20℃. When the wear test performs at 200℃, the substrate wear mechanism is adhesive wear and fatigue wear. The wear mechanism of borocarburized layer is main abrasive wear at 20℃ and 200℃. And the wear mechanism of both substrate and borocarburized layer are main oxidation wear and adhesive wear at 500℃. The borocarburized layer effectively improves the wear resistance of low carbon steel due to the higher hardness and great thermal stability at high temperature.

scholarly journals Effects of plasma surface Ta alloying on the tribology behavior of γ-TiAl

2021 ◽  
Vol 57 (1) ◽  
pp. 97-104
Author(s):  
D.-B. Wei ◽  
X. Zhou ◽  
F.-K. Li ◽  
M.-F. Li ◽  
S.-Q. Li ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Alloy Layer ◽  
Wear Volume ◽  
Plasma Surface ◽  
Glow Plasma ◽  
Oxidation Wear ◽  
Plasma Surface Alloying Technique

To improve the wear resistance of ?-TiAl alloy, Ta alloy layer was prepared on surface by double glow plasma surface alloying technique. The tribology behavior of Ta alloy layer against Si3N4 at 25?, 350? and 500? were comparatively studied. The results showed that Ta alloy layer comprised a deposition layer and a diffusion layer. The deposition layer played a role in protection as a soft film. With the increase of temperature, the wear mechanism of ?-TiAl changed from abrasive wear to coexistence of abrasive wear and oxidation wear. Ta alloy layer?s wear mechanism changed from adhesive wear to coexistence of adhesive wear and oxidation wear. Surface Ta alloying process significantly reduced the wear volume, the specific wear rate and the friction coefficient of ?-TiAl and improved the wear resistance properties of ?-TiAl.

scholarly journals A comparison of wear behaviour of heat-resistant steel engine valves and TiAl engine valves

2019 ◽  
Vol 234 (10) ◽  
pp. 1549-1562
Author(s):  
Fuqiang Lai ◽  
Shengguan Qu ◽  
Haidi Qin ◽  
Roger Lewis ◽  
Tom Slatter ◽  
...  
Keyword(s):  
Natural Gas ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Internal Combustion ◽  
Wear Loss ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Engine Valve ◽  
Heat Resistant ◽  
Engine Valves

The increasing demand for higher performance internal combustion engines has led to higher temperatures in the combustion chamber. As a result, TiAl valves have been investigated with a view to their use in a natural gas fuelled diesel internal combustion engine, taking advantage of their low density and good high-temperature resistance. In this work, comparison bench tests for traditional steel valves and TiAl valves were carried out through the use of specially designed wear testing apparatus. Compared to the traditional valves made from heat-resistant steel (X60, X85), the TiAl valves have 50% lower mass, leading to a decrease in the impact seating forces during the engine operation. With the reduction of the inertia of engine valve movement, the dynamic characteristics of the engine valve train system can be optimized. Each contact pair of valve and seat insert was tested for 3 million impact cycles. Compared to the austenitic exhaust valves (X60) tested at 700 ℃, the TiAl valve had better wear resistance and the wear loss decreased by 24.8 %. The predominant wear mechanism is considered to be a combination of oxidative wear and adhesive wear. However, for the intake valves tested at 400 ℃, the wear loss of the TiAl valve was three times higher than the martensitic intake valves (X85). The predominant wear mechanism can be identified as abrasive wear and adhesive wear. It is therefore concluded that the TiAl exhaust valve is a potential solution for a natural gas fuelled diesel.

Research on Wear Mechanism of Surface Build-Up Welding Material of Brake Disc for Drilling Rig

2008 ◽  
Vol 373-374 ◽  
pp. 535-538 ◽  
Author(s):  
Xin Hua Wang ◽  
Si Wei Zhang ◽  
De Guo Wang
Keyword(s):  
Wear Mechanism ◽  
Adhesive Wear ◽  
Variable Temperature ◽  
Surface Film ◽  
Brake Disc ◽  
Tribological Behaviour ◽  
Welding Material ◽  
Drilling Rig ◽  
Friction Temperature ◽  
Brake Block

In order to improve resisting performance of heat, wear and erosion as well as anti-thermal fatigue, surface build-up welding material of brake-disc for drilling rig with better performance is developed, and its wear mechanism is investigated based on friction and wear experiment at variable temperature. Morphology, constituents and phase structure of wear surface of brake disc are analyzed by employing SEM, EDAX and XRD when thermal equilibrium temperature is at 150°C and 300°C, and its tribological behaviour and wear mechanism of surface build-up welding materials are revealed. In initial stage of wear, friction temperature is lower and hard particles like AL2O3, SiO2, SiC, TiO in brake block plough the surface of brake-disc, oxide layer forms on friction surface with rise of friction temperature and its cracking and regenerating become a major way of wear, meanwhile hard grains in brake block slough off due to frequent ploughing and three-body abrasive wear occurs, and spalling of surface film is mainly caused by fatigue. In stage of high temperature wear, oxidization wear and plastic deformation of brake-disc increase greatly, brake-block starts to soften, severe adhesive wear occurs and spalling of surface film is mainly caused by adhesive tearing. Wear mechanism of brake-disc is comprehensive effects of abrasive, oxidizing and adhesive wear.

Wear Analysis of Head-Disk Interface During Contact

2005 ◽  
Vol 127 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Wei Peng ◽  
James Kiely ◽  
Yiao-Tee Hsia
Keyword(s):  
Hard Disk Drive ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Contact Stiffness ◽  
Hard Disk ◽  
Disk Drive ◽  
Head Disk Interface ◽  
Wear Coefficient ◽  
Disk Interface ◽  
Fly Height

To achieve a higher storage density in a hard disk drive, the fly height of the air bearing slider, as part of the magnetic spacing, has to be minimized. At an ultralow fly height, the intermittent–continuous contact at the head–disk interface (HDI) is unavoidable and directly affects the mechanical and magnetic performance of the hard disk drive, and is of great interest. The HDI wear has a nonlinear and time-varying nature due to the change of contact force and roughness. To predict the HDI wear evolution, an iterative model of Coupled Head And Disk (CHAD) wear, is developed based on the contact mechanics. In this model, a composite transient wear coefficient is adopted and multiple phases of the wear evolution are established. A comprehensive contact stiffness is derived to characterize the contact at the HDI. The abrasive and adhesive wear is calculated based on the extended Archard’s wear law. The plastic and elastic contact areas are calculated with a three-dimensional (3D) sliding contact model. Based on the CHAD wear model, for the first time, the coupling between head and disk wear evolutions is thoroughly investigated. Accelerated wear tests have also been performed to verify the disk wear effect on the slider wear. A wear coefficient drop with time is observed during the tests and it is attributed to a wear mechanism shift from abrasive to adhesive wear. A shift in the type of contact from plastic to elastic accounts for the wear mechanism change.

scholarly journals Microstructure and Properties of AA6061/SiCp Composites Sintered under Ultra High-Pressure

2020 ◽  
Vol 10 (20) ◽  
pp. 7363
Author(s):  
Lei Xu ◽  
Erkuo Yang ◽  
Yasong Wang ◽  
Changyun Li ◽  
Zhiru Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Wear Property ◽  
Ultra High Pressure ◽  
High Pressure Sintering

Ultra high-pressure sintering (UHPS) was used to prepare AA6061/SiCp composites with different contents and the effect of sintering temperatures on microstructure and mechanical properties was investigated in this study. The results showed that a uniform distribution of nano-SiC particles (N-SiCp) is obtained by the UHPS method. With the increase in N-SiCp contents, the higher hardness and better wear resistance could be inspected. The interfacial reactions and Al4C3 phase appeared above 550 °C. The relative density of composites first increased and then decreased; with the temperature raising it reached 99.58% at 600 °C. The hardness and wear property showed the same trend with the hardness reaching 52 HRA and wear rate being 1.0 × 10−6 g/m at 600 °C. Besides, the wear mechanism of the composites is mainly composed of abrasive wear and adhesive wear.

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