EFFECT OF COARSE-TO-FINE WC GRAIN RATIO ON MECHANICAL PROPERTIES AND ABRASIVE WEAR OF WC-8Co CEMENTED CARBIDES

Tribologia ◽  
2016 ◽  
Vol 265 (1) ◽  
pp. 103-115
Author(s):  
Der-Liang YUNG ◽  
Maksim ANTONOV ◽  
Irina HUSSAINOVA ◽  
Renno VEINTHAL ◽  
Sture HOGMARK
Keyword(s):  
Abrasive Wear ◽  
Rupture Strength ◽  
Ultrafine Grain ◽  
Cemented Carbides ◽  
Wear Properties ◽  
Fine Grain ◽  
Material Hardness ◽  
Fine Tungsten ◽  
Grain Distribution ◽  
Coarse To Fine

This study performs a comprehensive analysis concerning the amount of fine tungsten carbide (WC) grains needed for the appropriate reinforcement of the cobalt (Co) metallic binder in WC-8Co cemented carbides. The goal is to investigate the balance of coarse-to-fine grain distribution to achieve overall improvement of the material’s mechanical and wear properties. All samples possessed the same WC-8Co binder content, therefore, allowing the role of grain size distribution to be tested. It was found that a ratio of 8:1 wt% of coarse to ultrafine grain WC yielded an appropriate balance between material hardness, fracture toughness, and rupture strength. Upon adding grain growth inhibitors vanadium carbide (VC) and chromium carbide (Cr3C2), the overall wear resistance is further improved compared to undoped composites when samples are tested under abrasive wear conditions.

scholarly journals Yield Stress Model for Natural Debris Flows in Presence of Fine and Coarse–Grained Sediments

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1865
Author(s):  
Leonardo Schippa
Keyword(s):  
Yield Stress ◽  
Debris Flows ◽  
Rheological Behaviour ◽  
Coarse Fraction ◽  
Coarse Grained ◽  
Stress Model ◽  
Coarse Sediment ◽  
Fine Grain ◽  
Sediment Fraction ◽  
Coarse To Fine

When dealing with natural geo–hazards, it is important to understand the influence of sediment sorting on debris flows. The presence of coarse fraction is one of the aspects which affects the rheological behaviour of natural viscous granular fluid mixtures. In this paper, experiments on reconstituted debris flow mixtures with different coarse–to–fine sediment ratios are considered. Such mixtures behave just as non–Newtonian yield stress fluids and their rheological behaviour is largely affected by the presence of coarse fraction. Experimental results demonstrate that yield stress is very sensitive not only to bulk sediment concentration but also to coarse sediment fraction. A novel yield stress model is presented. It accounts for an empirical grading function depending on the coarse–to–fine grain content. The yield stress model performed satisfactorily in comparison with the experiments, showing that it is almost independent of the coarse–to–fine grain fraction in case of dominant coarse sediment content.

Effect of CeO2 addition on microstructure and tribological characteristics of laser cladded Cu10Al–MoS2 coating under oil lubrication

2021 ◽  
pp. 146442072110309
Author(s):  
Shao Lifan ◽  
Ge Yuan ◽  
Kong Dejun
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanism ◽  
Mass Fraction ◽  
Friction Reduction ◽  
Depth Of Field ◽  
Oil Lubrication ◽  
Wear Properties ◽  
Fatigue Wear ◽  
Wear Rates ◽  
Mass Fractions

In order to improve the friction and wear properties of Cu10Al–MoS2 coating, the addition of CeO2 is one of the present research hot spots. In this work, Cu10Al–MoS2 coatings with different CeO2 mass fractions were successfully fabricated on Q235 steel using a laser cladding. The microstructure and phase compositions of obtained coatings were analyzed using an ultra-depth of field microscope and X-ray diffraction, respectively. The friction-wear test was carried out under oil lubrication using a ball-on-disk wear tester, and the effects of CeO2 mass fraction on the microstructure, hardness, and friction-wear properties were studied, and the wear mechanism was also discussed. The results show that the laser cladded Cu10Al–MoS2 coatings with the different CeO2 mass fractions were mainly composed of Cu9Al4, Cu, AlFe3, Ni, MoS2, and CeO2 phases. The Vickers-hardness (HV) of Cu10Al–8MoS2–3CeO2, Cu10Al–8MoS2–6CeO2, and Cu10Al–8MoS2–9CeO2 coatings was 418, 445, and 457 HV0.3, respectively, which indicates an increase in hardness with the increase of CeO2 mass fraction. The average coefficients of friction (COF) and wear rates decrease with the increase of CeO2 mass fraction, presenting the outstanding friction reduction and wear resistance performances. The wear mechanism of Cu10Al–MoS2 coatings is changed from abrasive wear with slight fatigue wear to abrasive wear with the increase of CeO2 mass fraction.

Wear properties of cemented carbides/Cu-based alloy composite strengthening materials for milling shoes

Wear ◽  
2006 ◽  
Vol 260 (7-8) ◽  
pp. 699-704 ◽  
Author(s):  
Xinhong Wang ◽  
Min Zhang ◽  
Zengda Zou ◽  
Shiyao Qu
Keyword(s):  
Cemented Carbides ◽  
Alloy Composite ◽  
Wear Properties

scholarly journals Plasma-Assisted Chemical Vapor Deposition of TiBN Coatings on Nanostructured Cemented WC-Co

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1680
Author(s):  
Matija Sakoman ◽  
Danko Ćorić ◽  
Mateja Šnajdar Musa
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Hot Isostatic Pressing ◽  
Base Material ◽  
Surface Preparation ◽  
Chemical Vapor ◽  
Hard Coatings ◽  
Cemented Carbides ◽  
Wear Properties ◽  
Coating Adhesion

The plasma-assisted chemical vapor deposition (PACVD) technique has shown many advantages in applications, where thin coatings with superior wear properties are demanded, especially for geometrically complex parts. In this study, multilayered gradient TiBN coatings that were deposited on nanostructured cemented carbides by the PACVD method were investigated. Nanostructured samples of cemented carbides with the addition of 5 and 15 wt.% Co were sintered by the hot isostatic pressing, sinter-HIP technique. Surface preparation was conducted on samples in order to enable maximum coating adhesion. Tests that were conducted on produced samples aimed to investigate the mechanical and physical properties of coated samples. These tests included nanoindentation, surface layer characterization, and coating adhesion evaluation while using the Rockwell and scratch test. The obtained results confirmed that the PACVD process can be utilized for applying thin hard coatings to nanostructured cemented carbides that are produced by the sinter HIP process, resulting in a base material/ coating system that exhibits excellent physical and mechanical properties. The results presented in this paper give a valuable contribution to the research of TiBN coating systems and their potential for application under heavy wear conditions.

scholarly journals Effects of Cr3C2 Addition on Wear Behaviour of WC-Co Based Cemented Carbides

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 895 ◽  
Author(s):  
Luca Boccarusso ◽  
Fabio Scherillo ◽  
Umberto Prisco
Keyword(s):  
Grain Size ◽  
Rupture Strength ◽  
Ceramic Materials ◽  
Extrusion Process ◽  
Wear Behaviour ◽  
Cemented Carbides ◽  
Tribological Behaviour ◽  
Wear Performance ◽  
Bulk Hardness ◽  
Wear Tests

Microstructure, hardness, transverse rupture strength, and abrasion resistance of WC-10 wt% Co cemented carbides modified with the addition of different mass fraction of Cr3C2, in the range of 0–3 wt%, are studied. The influence of the microstructure, composition and hardness on the mechanical properties and wear resistance is analysed. Considering that the material under investigation can be used as die for the extrusion process of hard ceramic materials, the tribological behaviour was evaluated by performing sliding wear tests in wet conditions using a block-on-ring tribometer. Wear mechanism principally based on binder removal and subsequent fragmentation and microabrasion of the WC grains is proposed. Carbide grain size and bulk hardness can be tuned as function of specific applications by adding different amounts of Cr3C2. In particular, increasing hardness and reducing grain size by the addition of Cr3C2 are demonstrated to considerably enhance the wear performance of these carbides.

Grain Refinement of an Al-Cu-Mg Alloy by Microalloying and Common Thermo-Mechanical Treatment

2007 ◽  
Vol 546-549 ◽  
pp. 917-922
Author(s):  
Bao Lin Wu ◽  
Gui Ying Sha ◽  
Yi Nong Wang ◽  
Yu Dong Zhang ◽  
Claude Esling
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Mechanical Treatment ◽  
Grain Structure ◽  
Mg Alloy ◽  
Ultrafine Grain ◽  
Fine Grain ◽  
Thermo Mechanical Treatment ◽  
Ultrafine Grain Structure ◽  
Thermal Stability Of

Heavy deformation plus micro alloying could be an effective way to obtain ultrafine grain structure of metals. In the present work, an Al-Cu-Mg alloy was microalloyed with Zr to obtain homogeneous precipitates and then heavily deformed by conventional forging at high temperature. The possible refining processing routes were studied and the superplasticity behaviors of the alloy was investigated. Results show that the micro alloyed alloy can be stably refined to 3-5μm under conventional processing routes. The Al-3Zr precipitates act both as additional sites to enhance recrystallization nucleation rate and pins to impede grain growth to increase the thermal stability of the fine grain structure. However, as the Al3Zr precipitates remains along grain boundaries, the superplastic capability of the material is not high. At 430°C with 1×10-4S-1 strain rate, the elongation obtained was 260%.

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