scholarly journals Structure and Properties of New Antifriction Composites Based on Tool Steel Grinding Waste

2021 ◽  
Vol 13 (16) ◽  
pp. 8823
Author(s):  
Tetiana Roik ◽  
Ahmad Rashedi ◽  
Taslima Khanam ◽  
Abhay Chaubey ◽  
Gurusami Balaganesan ◽  
...  
Keyword(s):  
Tool Steel ◽  
Tribological Properties ◽  
High Speed ◽  
Production Cycle ◽  
Steel Matrix ◽  
Friction Behavior ◽  
Mechanical And Tribological Properties ◽  
Antifriction Properties ◽  
Antifriction Composites ◽  
The Impact

This article investigates the impact of manufacturing technology on the structure, mechanical, and tribological properties of new antifriction composite materials based on R6M5 high-speed tool steel grinding waste. The characteristics of the new composite’s structure formation and its impact on properties after use of the established technological modes, including grinding waste regeneration, were illustrated. It was demonstrated that such technology is capable of ensuring microheterogeneous structure. The material’s structure consists of the metal matrix based on R6M5 high-speed tool steel waste and uniformly distributed CaF2 solid lubricant in the steel matrix. As compared to known iron-based composites, this structure promotes a high degree of mechanical and tribological properties. During tribological tests, anti-seize thin films of 15–20 μm are formed on the contacting surfaces. These constantly renewable films contribute to the high antifriction properties of the composite under the studied friction conditions and provide a self-lubricating effect. Such films fully cover both the material’s surface and the counterface. The formation of antifriction films results in the self-lubrication mode. The findings of the study open up the possibility of predicting the friction behavior of a composite at high temperatures by selecting the initial metal grinding waste to ensure the appropriate level of properties. The extensive use of various alloy steel-based industrial grinding waste in the re-production cycle would significantly contribute to resolving the global environmental problem of protecting the environment from pollution.

Electroless Nickel-Phosphorus Composite Coatings

2016 ◽  
Vol 6 (1) ◽  
pp. 14-50 ◽  
Author(s):  
Prasanna Gadhari ◽  
Prasanta Sahoo
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Composite Coatings ◽  
Electroless Nickel ◽  
Friction Behavior ◽  
Factors Affecting ◽  
Conductive Materials ◽  
Mechanical And Tribological Properties ◽  
Coating Methods ◽  
Soft Particles

Electroless nickel composite coatings possess excellent mechanical and tribological properties such as, hardness, wear and corrosion resistance. Composite coatings can easily be coated not only on electrically conductive materials but also on non-conductive materials like as fabrics, plastics, rubber, etc. This review emphasizes on the development of electroless nickel composite coatings by incorporating different types of hard/soft particles (micro/nano size) in the electroless Ni-P matrix to improve the mechanical and tribological properties of the coatings. The preparation of electroless bath for nickel-phosphorus composite coating, methods to incorporate hard and/or soft particles in the bath, factors affecting the particle incorporation in the coating and its effect on coating structure, hardness, wear resistance, friction behavior, corrosion resistance, and mechanical properties are discussed thoroughly.

scholarly journals Impact of Cutting Environments on Sustainable Machining of H13 Tool Steel Alloy

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Vincent A Balogun ◽  
Isuamfon F Edem ◽  
Etimbuk B Bassey
Keyword(s):  
Tool Life ◽  
Tool Steel ◽  
High Speed ◽  
Machining Process ◽  
Steel Alloy ◽  
High Speed Machining ◽  
Sustainable Machining ◽  
H13 Tool Steel ◽  
Green Machining ◽  
The Impact

The use of electrical energy and coolants/lubricants has been widely reported in mechanical machining. However, increased research and process innovation in high speed machining has brought about optimised manufacturing cycle times. This has promoted dry machining and the use of minimum quantity lubrication (MQL). This work understudies the impact of different cutting environments in machining H13 tool steel alloys at transition speed regime with emphasis on sustainable machining of the alloy. To achieve this, end milling tests were performed on AISI H13 steel alloy (192 BHN) on a MIKRON HSM 400 high speed machining centre using milling inserts. After each cutting pass, the milling insert was removed for tool wear measurement on the digital microscope. The electrical power consumed was measured with the Fluke 435 power clamp meter mounted on the three phase cable at the back of the machine. It was discovered that MQL has a promising advantage in terms of tool life with 25 minutes of machining, net power requirement of 10% when compared to dry cutting, and environmental benefits when machining H13 tool steel alloy. This work is fundamentally important in assessing the environmental credentials and resource efficiency regime for green machining of H13 tool steel alloysKeywords— H13 tool steel, green machining, process optimization, tool life, cutting environments, energy consumption 

scholarly journals Mechanical and tribological properties of B-C-N coatings sliding against different wood balls

2019 ◽  
Vol 26 (1) ◽  
pp. 402-411 ◽  
Author(s):  
Zhiwei Wu ◽  
Yan Wang ◽  
Sihao Li ◽  
Xiaoyong Wang ◽  
Zhaojun Xu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
316L Stainless Steel ◽  
Rf Magnetron Sputtering ◽  
Chemical Compositions ◽  
Low Friction ◽  
Friction Behavior ◽  
Mechanical And Tribological Properties ◽  
Bonding Structure ◽  
C And N

AbstractBCN coatings with different chemical compositions were prepared using RF magnetron sputtering via adjusting N2 flow. The influence of N2 flow on the bonding structure, mechanical and tribological properties of coating was studied. The structural analysis indicated the coexistence of B-N, B-C, and N-C bonds, suggesting the formation of a ternary BCN hybridization. The maximum Vickers hardness of 1614.7 HV was obtained at the low N2 flow (5 sccm), whereas the adhesion strength of BCN coatings on 316L stainless steel was improved with an increase of N2 flow. The friction behavior of BCN coatings sliding against different materials (acerbic, beech and lauan wood) was performed using ball-on-disk tribo-meter in air. The low friction coefficient was easier to obtain as sliding against hardwood i.e. acerbic balls. BCN-5 and BCN-10 coatings presented better wear resistance regardless of softwood or hardwood, whilst other two coatings were more suitable for mating softwood i.e. beech and lauan.

scholarly journals Tribological properties of boron carbonitride coatings sliding against different wood (acerbic, beech, and lauan) balls

2019 ◽  
Vol 28 ◽  
pp. 096369351987573 ◽  
Author(s):  
Zhiwei Wu ◽  
Sihao Li ◽  
Zhaojun Xu ◽  
Qianzhi Wang ◽  
Fei Zhou
Keyword(s):  
Bias Voltage ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
Substrate Bias ◽  
Boron Carbonitride ◽  
Friction Behavior ◽  
Substrate Bias Voltage ◽  
Mechanical And Tribological Properties ◽  
C And N

Boron carbonitride (BCN) coatings were prepared using radio frequency (RF) magnetron sputtering via adjusting substrate bias voltage from −50 V to −200 V. The mechanical and tribological properties of the coatings were investigated. The coexistence of B–N, B–C, and N–C bonds was detected in coatings according to X-ray photoelectron spectroscopy analysis, indicating the formation of ternary BCN hybridization. The hardness of BCN coatings increased from 14.4 GPa to 24.3 GPa with an increase of substrate bias voltage, while their adhesion strength on substrate decreased. The friction behavior of BCN coatings sliding against different wood (acerbic, beech, and lauan) balls was examined using a ball-on-disk tribometer. The average friction coefficient fluctuated in a range of 0.74–1.02. The wear track of BCN coating sliding against hardwood (acerbic) presented obvious scratches, which were not noted as sliding against other softwood balls in comparison.

Influence of thermal cycling modes on VK8 hard alloy mechanical and tribological properties

2020 ◽  
pp. 55-65
Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Wear Resistance ◽  
Thermal Cycling ◽  
Hard Alloy ◽  
Tribological Properties ◽  
High Speed ◽  
Metal Cutting ◽  
Hard Alloys ◽  
Mechanical And Tribological Properties

Hard alloys are popular materials widely used in the toolmaking industry. Refractory carbides included in their composition make carbide tools very hard (80 to 92 HRA) and heat-resistant (800 to 1000 °С) so as they can be used at cutting speeds several times higher than those used for high-speed steels. However, hard alloys differ from the latter by lower strength (1000 to 1500 MPa) and the absence of impact strength, and this constitutes an urgent problem. We studied the influence of thermal cycling modes on the mechanical and tribological properties of VK8 (WC–8Co) hard alloy used in the manufacture of cutters and cutting inserts for metal working on metal-cutting machines. As the object of study, we selected 5×5×35 mm billets made of VK8 (WC–8Co) alloy manufactured by powder metallurgy methods at Dimitrovgrad Tool Plant. The following criteria were selected for heat treatment mode evaluation: Vickers hardness, flexural strength, and mass wear resistance (as compared to the wear of asreceived samples that were not heat treated). Plates in the initial state and after heat treatment were subjected to abrasion tests. Wear results were evaluated by the change in the mass of plates. Regularities of the influence of various time and temperature conditions of heat treatment on the tribological properties of products made of VK group tungsten hard alloys were determined. An increase in the number of thermal cycling cycles improved such mechanical properties of the VK8 hard alloy as strength and hardness. When repeating the cycles five times, an increase in abrasive wear resistance was obtained compared to the initial nonheat-treated sample. The elemental composition of the VK8 hard alloy changed insignificantly after thermal cycling, only a slight increase in oxygen was observed on the surface of plates. The grain size after thermal cycling increased in comparison with the initial VK8 hard alloy. It was found that VK8 hard alloy thermocyclic treatment leads to a change in the phase composition. X-ray phase analysis showed the presence of a large amount of α-Co with an hcp-type lattice on the surface of a hard alloy and a solid solution of WC in α-Co. A change in the cobalt modification ratio causes a decrease in microstresses. An analysis of the carbide phase structure state showed that the size of crystallites and microstresses changed after thermal cycling. The lattice constant of the cobalt cubic solid solution decreased, which may indicate a decrease in the amount of tungsten carbide and carbon dissolved in it. Statistical processing of experimental results included the calculation of the average value of the mechanical property, its dispersion and standard deviation in the selected confidence interval.

Modeling the impact–sliding wear characteristics of rare earth additive iron-based hardfacing alloys

2017 ◽  
Vol 231 (11) ◽  
pp. 1486-1499 ◽  
Author(s):  
Yogesh Kumar Singla ◽  
DK Dwivedi ◽  
Navneet Arora
Keyword(s):  
Rare Earth ◽  
Tribological Properties ◽  
Rare Earth Oxide ◽  
Oxide Content ◽  
Statistical Regression ◽  
Austenite Grain Size ◽  
Mechanical And Tribological Properties ◽  
Hardfacing Alloy ◽  
Iron Based ◽  
The Impact

This paper presents a systematic study of the effect of the cerium oxide content on the mechanical, microstructural and tribological properties of iron-based alloys. The results indicate that the microstructure of the hardfaced alloys is mainly composed of austenite, MC and M7C3 carbides. The primary austenite grain size was refined at first and then coarsened with the increase of the rare earth oxide additions. Meanwhile, the hardness of the hardfacing alloy was also increased. The increased area fraction of carbides was found to be beneficial for enhanced wear resistance. A statistical regression model was developed and verified with a number of test cases in order to evaluate the adequacy of the model. The optimal amount of rare earth was found to be less than 6 wt.%; below this composition, the microstructural, mechanical and tribological properties were excellent.

scholarly journals Investigation of changes in the properties of diamond-like films under friction by the XPS method

2021 ◽  
Vol 2131 (5) ◽  
pp. 052038
Author(s):  
A V Sidashov ◽  
M V Boiko ◽  
E I Luneva ◽  
A M Popov
Keyword(s):  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Etching Time ◽  
Energy Position ◽  
Dlc Coatings ◽  
Mechanical And Tribological Properties ◽  
Dlc Coating ◽  
Electron Line ◽  
Antifriction Properties

Abstract The combination of unique physicochemical, mechanical and tribological properties of diamond-like coatings determines the prospects for their use in critical friction units, including those operating in a rarefied atmosphere and vacuum. The properties of diamond-like carbon (DLC) coatings depend on the contribution of the sp2 and sp3 fractions of the carbon hybrid atomic electron orbitals. Modern methods of determining the graphite and diamond proportion in coatings are time-consuming and insufficiently accurate. In addition, the determination of the sp3/sp2 ratio is often difficult due to the displacement of the energy position of the C1s electron line. In this paper, the change in the chemical state of carbon over the thickness of a diamond-like coating is studied by X-ray photoelectron spectroscopy. Analysis of the carbon line fine structure of the differential graphite spectra (sp2 bonds) and diamond (sp3 bonds) allowed us to establish the parameter δ, which determines the ratio of the graphite and diamond components in the DLC coating. Profiling with Ar+ ions of the diamondlike coating surface showed that with an increase in the etching time, the proportion of amorphized carbon increases, which means that the antifriction properties increase with the abrasion of the coating. The obtained regularities allow us to predict changes in the tribological properties of DLC coatings during operation. Ion profiling also allows to determine the thickness of coatings with high accuracy.

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