scholarly journals Effect of Nickel–Phosphorus and Nickel–Molybdenum Coatings on Electrical Ablation of Small Electromagnetic Rails

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1082
Author(s):  
Li-Shan Hsu ◽  
Pao-Chang Huang ◽  
Chih-Cheng Chou ◽  
Kung-Hsu Hou ◽  
Ming-Der Ger ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Hardness ◽  
Electrical Energy ◽  
High Wear Resistance ◽  
X Ray Diffraction ◽  
Molybdenum Coating ◽  
Surface Areas ◽  
Heat Treated ◽  
Electrochemically Deposited ◽  
Iron Material

The electromagnetic rail catapult is a device that converts electrical energy into kinetic energy, which means that the strength of electrical energy directly affects the muzzle speed of armature. In addition, the electrical conductivity, electromagnetic rails and armature surface roughness, and the holding force of the rail are influencing factors that cannot be ignored. However, the electric ablation on the surface of the electromagnetic rails caused by high temperatures seriously affects the service life performance of the electromagnetic catapult system. In this study, electrochemically deposited nickel-phosphorus and nickel-molybdenum alloy coatings are plated on the surface of electromagnetic iron rails and their effects on the reduction of ablation are investigated. SEM (scanning electron microscopy) with EDS (energy dispersive spectroscopy) detector, XRD (X-ray diffraction), 3D optical profiler, and Vickers microhardness tester are used. Our results show that the sliding velocity of the armature decreases slightly with the increased roughness of the rail coating surface. On the other hand, the area of electric ablation on the rail surface is inversely related to the hardness of the rail material. The electrically ablated surface areas of the rails are in: annealed nickel–molybdenum < nickel–molybdenum < annealed nickel–phosphorus < nickel–phosphorus < iron material. Heat treatment at 400 and 500 °C, respectively for Ni–P and Ni–Mo alloys, significantly increases hardness due to the precipitation of intermetallic compounds such as Ni3P and Ni4Mo phases. Comprehensive data analysis shows that the annealed nickel–molybdenum coating has the best electrical ablation wear resistance. The possible reason for that might be attributed to the high hardness of the heat-treated nickel–molybdenum coating. In addition, the thermal resistance capability of molybdenum is better than that of phosphorus, which might also contribute to the high wear resistance to electric ablation.

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

Phase, microstructure, and wear behavior of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites

2019 ◽  
Vol 234 (3) ◽  
pp. 467-480
Author(s):  
Akash Saxena ◽  
Neera Singh ◽  
Bhupendra Singh ◽  
Devendra Kumar ◽  
Kishor Kumar Sadasivuni ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Metal Matrix ◽  
Alloy Composition ◽  
Wear Behavior ◽  
High Hardness ◽  
Industrial Applications ◽  
High Wear Resistance ◽  
Wear Properties ◽  
Metal Matrix Nanocomposites ◽  
Matrix Nanocomposites

In the present work, phase, microstructure, and wear properties of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites have been studied. Composites using 2 wt.% and 5 wt.% of Si and rest Fe powder mix were synthesized via powder metallurgy and sintered at different temperature schedules. Iron–silicon alloy specimens were found to have high hardness and high wear resistance in comparison to pure iron specimens. Addition of 5 wt.% and 10 wt.% alumina reinforcement in Fe–Si alloy composition helped in developing iron aluminate (FeAl2O4) phase in composites which further improved the mechanical properties i.e. high hardness and wear resistance. Formation of iron aluminate phase occurs due to reactive sintering between Fe and Al2O3 particles. It is expected that the improved behavior of prepared nanocomposites as compared to conventional metals will be helpful in finding their use for wide industrial applications.

ELID Grinding Technology of Nano-Ceramic Scalpel

2012 ◽  
Vol 468-471 ◽  
pp. 1560-1563 ◽  
Author(s):  
Ji Cai Kuai ◽  
Fei Hu Zhang ◽  
Ya Zhong Liu
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
High Hardness ◽  
High Wear Resistance ◽  
Preparation Technology ◽  
Elid Grinding ◽  
High Toughness ◽  
Edge Sharpness ◽  
Cutting Experiment ◽  
Promising Application

As the grain size of nano ceramic has reached nanometer grade, it possesses high hardness, high wear resistance and high toughness. Therefore, the scalpel made by nano ceramic has the virtue of high wear resistance, good corrosion resistance, long service life, non-toxic, non-static, sharp edge and so on, but the processing of this kind of scalpel is extremely difficult. This paper prepares the nano-ceramic scalpel by using ELID grinding technology, and also studies the thickness, surface roughness, edge sharpness of scalpel. The research results show that the thickness of prepared scalpel is 0.3 mm, the surface roughness is 6-60 nm and the edge radius is 200 nm, the cutting experiment on suture shows that this scalpel can meet the requirements of international standard for medical scalpel when the cutting force is less than 0.8 N. This further proves that the ELID grinding technology is suitable for the preparation of nano-ceramic scalpel. The preparation technology and technological equipment of nano-ceramic scalpel are proposed on the basis of above achievements, and this technology possesses promising application prospect.

Dry Sliding Wear Behavior of the Reinforced by Graphite Particle and Heat Treated of Recycled Aluminum AA6061 Based MMC Fabricated by Powder Metallurgy Method

2017 ◽  
Vol 740 ◽  
pp. 9-16
Author(s):  
Ahmed Sahib Mahdi ◽  
Mohammad Sukri Mustapa ◽  
Mahmod Abd Hakim Mohamad ◽  
Abdul Latif M. Tobi ◽  
Muhammad Irfan Ab Kadir ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Powder Metallurgy ◽  
Compression Strength ◽  
Sliding Wear ◽  
Wear Behavior ◽  
High Wear Resistance ◽  
Dry Sliding Wear ◽  
Powder Metallurgy Method ◽  
Heat Treated ◽  
Improvement Ratio

The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different microstructure and constituent powder metallurgy method. Five specimens were selected to investigate the compression strength and microhardness. The first, as fabricated specimen (as compacted), the second was as heat treated by quenching and aging process. Three specimens were mixed with Graphite particles as a reinforcement material. Compression strength values were tested for the specimens as fabricated and heat treated which were 195 and 300 MPa, respectively. The improvement ratio was 52% for the specimen as heat treated. On the other hand, high wear resistance was given by the specimen as heat treated, whereas, the lower wear strength was at the specimen mixed with 4.5% Graphite. These results were attributed to that the wear resistance related to the microhardness value.

scholarly journals Laser alloying of bearing steel with boron and self-lubricating addition

2016 ◽  
Vol 36 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Mateusz Kotkowiak ◽  
Adam Piasecki ◽  
Michał Kulka
Keyword(s):  
Wear Resistance ◽  
Calcium Fluoride ◽  
High Hardness ◽  
Bearing Steel ◽  
Operating Conditions ◽  
High Wear Resistance ◽  
Laser Alloying ◽  
Amorphous Boron ◽  
Rolling Bearings ◽  
Borided Layer

Abstract 100CrMnSi6-4 bearing steel has been widely used for many applications, e.g. rolling bearings which work in difficult operating conditions. Therefore, this steel has to be characterized by special properties such as high wear resistance and high hardness. In this study laser-boriding was applied to improve these properties. Laser alloying was conducted as the two step process with two different types of alloying material: amorphous boron only and amorphous boron with addition of calcium fluoride CaF2. At first, the surface was coated with paste including alloying material. Second step of the process consisted in laser re-melting. The surface of sample, coated with the paste, was irradiated by the laser beam. In this study, TRUMPF TLF 2600 Turbo CO2 laser was used. The microstructure, microhardness and wear resistance of both laser-borided layer and laser-borided layer with the addition of calcium fluoride were investigated. The layer, alloyed with boron and CaF2, was characterized by higher wear resistance than the layer after laser boriding only.

Microstructure and Property of Wear-Resistant Coating Layer by High-Frequency Induction Cladding on Mild Steel Surface

2011 ◽  
Vol 239-242 ◽  
pp. 773-776
Author(s):  
Li Yang ◽  
Gang Li
Keyword(s):  
Wear Resistance ◽  
Mild Steel ◽  
High Frequency ◽  
Coating Layer ◽  
High Hardness ◽  
Alloy Coating ◽  
Alloy Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Frequency Induction

In order to improve the wear resistance of mild steel products, the Fe-based alloy layer was melted on the surface of mild steel by high-frequency induction cladding. Using scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction observation of microstructure of the alloy coating, wear resistance of the coating was evaluated. The results showed that: between the coating and the substrate is metallurgical bonded; The microstructure of coating layer was compact actinomorphous structure with plentiful nubby and strip eutectics; Actinomorphous structure was mixed structure of martensite and γ alloy solid solution covered with a large number floriform and dendrite eutectic; The coating has high hardness and good wear resistance.

Possibilities of Preparing Tools Working in Conditions of Abrasion Wear with the Modification of the Tool Surfaces by Nitridation

2014 ◽  
Vol 635 ◽  
pp. 89-93
Author(s):  
Martin Orečný ◽  
Petra Lacková ◽  
Marián Buršák
Keyword(s):  
Wear Resistance ◽  
Nitrided Layer ◽  
High Hardness ◽  
Chromium Steel ◽  
Material Surface ◽  
Diffusion Annealing ◽  
Additional Increase ◽  
Abrasion Wear ◽  
Heat Treated

The proposed paper deals about the heat treatment of two types of chromium tool steels that are assigned to work in specific conditions of abrasion wear. The materials are heat treated to achieve high hardness for higher abrasion wear resistance. An additional increase of the materials abrasion wear resistance can be achieved by applying nitridation with diffusion annealing of the material surface. The paper deals about the influence of the material purity, his chemical composition on the process of diffusion, the quality of the nitrided layer of a vacuum smelted steel Bӧhler W400 VMR and a chromium steel X210Cr12.

scholarly journals Composition versus Wear Behaviour of Air Plasma Sprayed NiCr–TiB2–ZrB2 Composite Coating

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 273
Author(s):  
Ning Zhang ◽  
Nannan Zhang ◽  
Sheng Guan ◽  
Shumei Li ◽  
Guangwei Zhang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
High Hardness ◽  
High Energy ◽  
Wear Behaviour ◽  
Air Plasma ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball ◽  
Plasma Sprayed

The NiCr–TiB2–ZrB2 composite coating was deposited on the surface of blades made of steel (SUS304) using high-energy ball milling technology and air plasma spraying technology, which aimed to relieve the wear of the blades during operation. The influence of titanium diboride (TiB2) and zirconium diboride (ZrB2) on the microstructure and wear resistance of the coatings was investigated by X-ray diffraction, scanning electron microscopy, Vickers microhardness tester, and a wear tester. The results showed that the TiB2 and ZrB2 particles were unevenly distributed in the coatings and significantly increased the hardness and anti-wear, which contributed to their ultra-high hardness and extremely strong ability to resist deformation. The performance of the coatings was improved with the increase of the number of ceramic phases, while the hardness and wear resistance of the coating could reach their highest value when the TiB2 and ZrB2 respectively took up 15 wt.% of the total mass of the powder.

scholarly journals Experimental studies of different quenching media on mechanical and wear behavior of Al7075/SiC/Al2O3 hybrid composites

2020 ◽  
Vol 15 (55) ◽  
pp. 20-31
Author(s):  
M. Ravikumar ◽  
H.N. Reddappa ◽  
R. Suresh ◽  
M. Sreenivasa Reddy
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Hybrid Composites ◽  
Experimental Studies ◽  
Age Hardening ◽  
Wear Behaviour ◽  
High Wear Resistance ◽  
Al Alloy ◽  
Quenching Media ◽  
Heat Treated

The effects of SiC-Al2O3 particle in the Al alloy on the mechanical and wear characteristics of stir-casted Composites have been reported. The Al7075 is reinforced with 2, 4, 6 and 8 wt. % of (SiC + Al2O3) to manufacture the hybrid composite. Ceramic particulates were added into Al alloy to achieve the low wear rate and improving mechanical properties. Hardening of casted specimens at 480ºC for the duration of 2 hrs and the specimens were quenched into two different quenching media (water and ice cubes). Finally, age-hardening were carried out at the temperature of 160ºC for the duration of 4 hrs and cooled at room temperature. The tensile strength, hardness and wear behaviour of MMCs are evaluated on the un-treated and heat treated composite. The tensile strength and hardness of MMCs increases by incorporating SiC-Al2O3 particulates. The wear behaviour of the MMCs containing SiC-Al2O3 particulates revealed the high wear-resistance. The heat-treatment had considerably improved the properties when compared to the un-heat treated composites. The composites with the highest tensile strength, hardness and enhanced wear resistance were found in the composites quenched in ice cubes. Worned surfaces of the composite specimens were studied by using SEM and XRD analysis

scholarly journals Wear evaluation and microstructure analysis of cryogenically treated AISI 440C Bearing steel

2021 ◽  
Author(s):  
Idayan A ◽  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
Palanikumar K
Keyword(s):  
Wear Resistance ◽  
Cryogenic Treatment ◽  
Research Work ◽  
Bearing Steel ◽  
X Ray Diffraction ◽  
Deep Cryogenic Treatment ◽  
X Ray ◽  
Heat Treated ◽  
Increase Wear Resistance ◽  
Wear Evaluation

In this research work, two types of cryogenic treatment such as deep cryogenic treatment (-196oC) and shallow cryogenic treatment (-80oC) have been adopted for wear resistance to increase in AISI 440C bearing steel. This paper has been focused to increase Wear Resistance (WR) through deep micro structural analyses, and also attention has been made to correlate the microstructure with the wear character of Deep Cryogenic treated (DCT) specimens, Conventional Heat Treated (CHT) specimens and Shallow Cryogenic Treated (SCT) specimens. Micro structural examinations have been carried out in the specimens through Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-ray (EDAX) and X-Ray Diffraction (XRD). Wear characteristics of AISI 440C bearing steel has been studied. The outcome of the research disclosed that the DCT specimens have higher wear resistance than SCT and CHT specimens. The effective wear mechanisms recognized were the constitution of white layers and delamination of white layers. The microstructures of the materials have been varied through heat treatment process. The modification of Secondary Carbides (SCs) precipitation characteristics and its reduction of retained austenite in the microstructure have been correlated with wear character and these are the liable mechanism to raise the wear resistance of bearing steels through DCT.

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