An Analysis of Crater Wear Based on the Adhesive Wear Mechanism

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.

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The machinability of Al/B4C composites produced by hot pressing based on reinforcing the element ratio

Science and Engineering of Composite Materials ◽

10.1515/secm-2014-0068 ◽

2016 ◽

Vol 23 (6) ◽

pp. 743-750 ◽

Cited By ~ 2

Author(s):

Ergün Ekici ◽

Mahmut Gülesin

Keyword(s):

Surface Roughness ◽

Wear Mechanism ◽

Cutting Forces ◽

Hot Pressing ◽

Matrix Material ◽

Cutting Tools ◽

Cutting Speed ◽

Reinforcement Ratio ◽

Depth Of Cut ◽

Crater Wear

AbstractIn this study, the effects of the particle reinforcement ratio on cutting forces and surface roughness were investigated when milling particle-reinforced metal matrix composite (MMCp) produced by hot pressing with different cutting tools. Alumix 123 alloy as the matrix material and B4C particles with an average size of 27 μm and 5%, 10% and 15% ratio as reinforcing elements were used for the manufacture of composite materials. The experiments were carried out in dry cutting conditions with four different cutting speeds, constant feed rate and depth of cut. Changes depending on the increased reinforcement ratio in cutting forces and surface roughness values were investigated; the effects of 10% B4C reinforced composite on tool wear were also examined. It was observed that cutting forces increased with the increase in cutting speed and particle ratio with carbide cutting tools, and it was seen that the cutting forces on the cutting tools decreased when cutting speed decreased and the cutting forces increased as the reinforcement ratios increased. In addition, with increasing the cutting speed, the surface roughness of the machined surfaces of composite samples increased with the carbide tools, while the cubic boron nitride (CBN) tools have the opposite effect. While it was seen that flank and crater wear occurred on the cemented carbide cutting tools, abrasive, adhesive and other wear mechanism tools in addition to the main wear mechanism, no remarkable flank and crater wear occurred on CBN cutting tools.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1095.135 ◽

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.

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High Temperature Tribological Behavior of Borocarburized Layer on Q235 Steel

Materials Science ◽

10.5755/j02.ms.24682 ◽

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.

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

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb200617002w ◽

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.

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

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650119872093 ◽

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.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.373-374.535 ◽

2008 ◽

Vol 373-374 ◽

pp. 535-538 ◽

Cited By ~ 1

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.

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