scholarly journals On the Bonding Strength of Fe-Based Self-Fluxing Alloy Coating Deposited by Different Methods on the Steel Substrate

2018 ◽  
Vol 23 (2) ◽  
pp. 355-364
Author(s):  
E. Feldshtein ◽  
M. Kardapolava ◽  
O. Dyachenko
Keyword(s):  
Laser Beam ◽  
Bonding Strength ◽  
Steel Substrate ◽  
Dendritic Structure ◽  
Plasma Coating ◽  
Alloy Coating ◽  
Laser Remelting ◽  
Globular Structure ◽  
Metastable Structures ◽  
Boride Phases

Abstract In the present paper, the bonding strength of Fe-based self-fluxing alloy coating deposited by plasma spraying, gluing and laser remelting and alloying on the steel substrate have been investigated. When flame melting, a globular structure is formed. Against the background of the solid solution carbide-boride phases are clearly distinguishable, between which the Fe–Fe2B and Fe–FeB eutectic colonies are situated. Laser remelting leads to the formation of metastable structures, reinforced with dendrites, consisting of alloyed Fe-α and Fe-γ. At the low laser beam speeds the coating is melted completely with the formation of a cast structure with the dendrites. When the laser beam speed is increased, the dendritic structure gets fragmented. Structures of coatings alloyed with B4C and remelted by the laser beam vary with the increase of the spot speed. The bonding strength of coating without subsequent remelting decreases by 4–5 times in comparison with remelted. The bonding strength of the reinforced glue coating has adhesive and adhesive-cohesive character. When the load increases in the coating, microcracks develop, which gradually spread to the center of the bonding surface. For plasma coatings after laser remelting without additional alloying, the maximum bonding strength is observed with the minimum laser beam speed. With increasing the laser beam speed it decreases almost 1.5 times. In glue coatings reinforced with B4C particulates by laser remelting, the bonding strength is lower by 1.2–1.4 times in comparison with plasma coating.

scholarly journals Influence of nano-SiO2 on the bonding strength and wear resistance properties of polyurethane coating

2019 ◽  
Vol 26 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Fangfang Wang ◽  
Lajun Feng ◽  
Huini Ma ◽  
Zhe Zhai ◽  
Zheng Liu
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Composite Coating ◽  
Network Structure ◽  
Bonding Strength ◽  
Coating Layer ◽  
Steel Substrate ◽  
Polyurethane Coating ◽  
Nano Sio2

Abstract To improve the wear resistance of polyurethane (PU) coating and its adhesion to the steel substrate, a series of simple and practicable techniques were designed to mix nano-SiO2 with PU powder to cast a coating layer onto the steel. When the addition of nano-SiO2 was small, a network structure of PU-SiO2 was produced. It improved the wear resistance of the composite coating and its adhesion to the steel substrate. When the addition of nano-SiO2 was excessive, agglomerated nano-SiO2 particles not only affected the bond between the PU resin and the steel substrate but also became abrasive materials, intensifying the abrasion of the composite coating during friction. It resulted in lower bonding strength and poorer wear resistance of the composite coating. The wear rate and friction coefficient of 2 wt.% SiO2/PU composite coating were 1.52×10−6 cm3/min N and 0.31, respectively. Its wear resistance was about 10 times as high as that of the pure PU coating. Furthermore, a simple and practicable installation was designed to test the bonding strength between the coating and the steel substrate. The bonding strength between 2 wt.% SiO2/PU composite coating and the steel substrate was 7.33 MPa, which was 39% higher than that of the pure PU coating.

Mechanical Properties and Structure of Laser Beam and Wide Gap Brazed Joints Produced Using Mar M247-Amdry DF3 Powders

2018 ◽  
Author(s):  
Alexandre Gontcharov ◽  
Yuan Tian ◽  
Paul Lowden ◽  
Mathieu Brochu
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
Dendritic Structure ◽  
Gamma Prime ◽  
High Gamma ◽  
Weld Properties ◽  
Bulk Chemical ◽  
Brazed Joints ◽  
Properties Of Materials ◽  
Wide Gap

The microstructure and mechanical properties of materials produced by Wide Gap Brazing (WGB) and Laser Beam (LBW) cladding with different blends of Mar M247 and Amdry DF-3 brazing powders were studied. It was shown that LBW Mar M247 based materials comprised of 0.6 to 1 wt. % B were weldable. The weld properties were superior to WGB deposits with the same bulk chemical composition, due to the formation of a dendritic structure typical for welded joints, and the precipitation of cuboidal borides of Cr, Mo, and W in the ductile Ni-Cr based matrix. Both materials were found to have useful properties for 3D additive manufacturing (AM) and repair components manufactured from high gamma prime precipitation hardened superalloys.

scholarly journals The Microstructure of Annealed Galfan Coating on Steel Substrate

2012 ◽  
Vol 57 (2) ◽  
pp. 517 ◽  
Author(s):  
M. Żelechower ◽  
J. Kliś ◽  
E. Augustyn ◽  
J. Grzonka ◽  
D. Stróż ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Electron Diffraction ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Alloy Coating ◽  
Annealed Sample ◽  
Low Carbon ◽  
Interface Area ◽  
Two Phase ◽  
Al Content

The Microstructure of AnnealedGalfanCoating on Steel SubstrateThe commercially availableGalfancoating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially availableGalfansamples: Zn-rich pre-eutectoidηphase grains are surrounded by lamellar eutectics ofβ-Al andη-Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600°C/5 minutes). Only the monoclinic FeAl3Znxphase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znxphase, reported by several authors.

Microstructure characterization and evaluation of mechanical properties of stir rheocast AA2024/TiB2 composite

2019 ◽  
Vol 54 (7) ◽  
pp. 981-997
Author(s):  
Semegn Cheneke ◽  
D Benny Karunakar
Keyword(s):  
Mechanical Properties ◽  
Dendritic Structure ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Globular Structure ◽  
Cast Sample ◽  
X Ray ◽  
Weight Percentage ◽  
The Matrix ◽  
Fractured Surface

In this research, microstructure and mechanical properties of stir rheocast AA2024/TiB2 metal matrix composite have been investigated. The working temperature was 640℃, which was the selected semisolid temperature that corresponds to 40% of the solid fraction. Two weight percentage, 4 wt%, and 6 wt% of the TiB2 reinforcements were added to the matrix. The field emission scanning electron microscope micrographs of the developed composites showed a uniform distribution of the particles in the case of the 2 wt% and 4 wt% of the reinforcements. However, the particles agglomerated as the weight percentages of the reinforcement increases to 6%. The optical microscope of the liquid cast sample showed the dendritic structure, whereas the rheocast samples showed a globular structure. The X-ray diffraction analysis confirmed the distribution of the reinforcements in the matrix and the formation of some intermetallic compounds. Mechanical properties significantly improved by the addition of the reinforcements in the matrix. An increase in tensile strength of 13.3%, 40%, 28%, and 5% was achieved for the unreinforced rheocast sample, 2 wt%, 4 wt%, and 6 wt% reinforced rheocast samples respectively, compared to the liquid cast sample. An increase in 20% of hardness was attained for the composite with 2 wt% TiB2 compared to the liquid cast sample. According to the fractography analysis, small dimples were observed on the fractured surface of the unreinforced rheocast sample, whereas small and large voids were dominant on the fractured surface of the 2 wt% composite, which shows the ductile fracture mode.

Preparation and Properties Study of Laser Cladding of Ni-Based Alloy on Copper

2010 ◽  
Vol 455 ◽  
pp. 216-219
Author(s):  
Y.S. Wang ◽  
F.D. Zhu ◽  
N.W. Liu
Keyword(s):  
Plasma Spraying ◽  
Laser Cladding ◽  
Alloy Coating ◽  
Alloy Layer ◽  
Laser Remelting ◽  
Yag Laser ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Organization Analysis ◽  
Surface Performance

In order to improve the surface Performance of thick copperplate, A Ni- Cr alloy coating metallurgically bonded onto thick copperplate is performed by YAG laser remelting plasma spraying coating process. In laser cladding processing, it is difficult to get good metallurgical bonding between the layer and copperplate. Plasma spraying technology is developed to get a alloy layer on the surface of thick copperplate, and then using YAG laser cladding method to make a coating. The results of Micro organization analysis indicate that the cladding layer and substrate form favorable metallurgical bonding, as a narrow metallurgical bonding zone, about 3m in thickness. The structure is more compact compared with witch of plasma spraying coating, and the crystal grains are refined grain.

Investigation on the Bonding Strength between the Hard Alloy Cladding Layer and the Steel Substrate

2004 ◽  
Vol 471-472 ◽  
pp. 136-139
Author(s):  
Fu Tian Liu ◽  
S.X. Song ◽  
Jun Ru Yang ◽  
Wei Ling Huang ◽  
Zhao Qian Li
Keyword(s):  
Liquid Phase ◽  
Hard Alloy ◽  
Bonding Strength ◽  
Steel Substrate ◽  
Liquid Phase Sintering ◽  
Steel Plates ◽  
Tensile Fracture ◽  
Cladding Layer ◽  
Ternary Boride ◽  
Cladding Material

By virtue of the technology characteristics of liquid-phase sintering ternary boride hard alloy cladding material, two steel plates were bonded together by a ternary boride hard alloy cladding material through a liquid phase sintering procedure. The bonding strength between a hard alloy cladding layer and a steel substrate was characterized by means of measuring the bonding strength of two steel plates bonded by the hard alloy cladding layer. The bonding strength between hard alloy cladding layer and the steel substrate was measured by transverse rupture strength method, tensile fracture method and single side shear method, respectively. The results show that a firm metallurgical bonding is formed during the liquid phase sintering.

Electrodeposition of the Ni-Mo+MoO2 Composite Electrocoatings

2015 ◽  
Vol 228 ◽  
pp. 132-137 ◽  
Author(s):  
B. Łosiewicz ◽  
Grzegorz Dercz ◽  
Magdalena Popczyk
Keyword(s):  
Composite Coating ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Chemical Properties ◽  
Alloy Coating ◽  
Composite Component ◽  
Powder Particles ◽  
Physical And Chemical ◽  
And Chemical Properties

The Ni-Mo+MoO2composite coatings were obtained onto the steel substrate using anin situco-deposition of a Ni-Mo alloy and MoO2powder particles maintained in suspension in the potassium pyrophosphate bath. To characterize the physical and chemical properties of the obtained coatings, SEM, EDS, and XRD methods, were applied. It was found that the co-deposited MoO2particles strongly influenced the properties of the Ni-Mo alloy coating. In comparison with the comparable Ni-Mo deposit containing 45 at.% of Mo, the presence of MoO2embedded into the composite coating diminished the content of Mo alloyed with Ni to 23 at.%. The electrodeposited Ni-Mo+MoO2composite coating obtained under proposed electrochemical conditions contained 25 at.% of MoO2. The effect of the embedded MoO2as composite component on changes of the surface morphology and structure of the Ni-Mo binary alloy, was also discussed.

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