Microstructure and Mechanical Properties of TiAlNb Coating Deposited by APS and HVOF Spraying

2013 ◽  
Vol 747-748 ◽  
pp. 139-145
Author(s):  
Hong Jie Zeng ◽  
Lai Qi Zhang ◽  
Xin Yu He ◽  
You Cha Zhang ◽  
Pen Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Thermal Shock ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
Atmospheric Plasma ◽  
Oxide Content ◽  
Thermal Shock Test ◽  
Hvof Spraying ◽  
Lower Porosity

As a material intended for application in hot-dip galvanization, Ti28.15Al63.4Nb8.25Y (at %) coatings were deposited onto 316L stainless steel substrate using high velocity oxygen fuel (HVOF) and atmospheric plasma spray (APS), respectively. The influence of different thermal spraying techniques on the microstructure, phase transformation, porosity, bond strength and hardness values of Ti28.15Al63.4Nb8.25Y coatings was analyzed by scanning electron microscopy (SEM), X-ray diffraction, tensile test and other analysis methods. In addition, the thermal shock test of Ti28.15Al63.4Nb8.25Y coatings was carried out to evaluate the desquamation resistance and the model of invalidation. The results indicated that HVOF Ti28.15Al63.4Nb8.25Y coatings had more uniform and compact morphology than APS Ti28.15Al63.4Nb8.25Y coating and HVOF Ti28.15Al63.4Nb8.25Y coatings have lower porosity and oxide content. The coatings processed by HVOF had higher bond strength, microhardness and thermal shock resistance and displayed better mechanical properties than that prepared by APS.

Coatings characterization of Ni-based alloy applied by HVOF

2018 ◽  
Vol 90 (2) ◽  
pp. 336-343 ◽  
Author(s):  
José Cabral Miramontes ◽  
Gabriela Karina Pedraza Basulto ◽  
Citlalli Gaona Tiburcio ◽  
Patricia Del Carmen Zambrano Robledo ◽  
Carlos Agustín Poblano Salas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
High Performance ◽  
Thermal Spraying ◽  
Advanced Materials ◽  
Oxide Content ◽  
Coating Materials ◽  
Content Type ◽  
Thermal Spray Process ◽  
Spray Process

Purpose The thermal spraying technique of High-Velocity Oxygen Fuel (HVOF) coating was used to deposit coatings of an alloy composed of Ni-based substrates on stainless steel AISI 304. The aim of this study was to determine the mechanical properties such as hardness and bond strength that these coatings have when the spray distance is varied, as well as the microstructure and phases formed during the thermal spray process. Design/methodology/approach The coatings were applied by HVOF and characterized by scanning electron microscopy, image analysis, X-ray diffraction, microhardness and bond strength to analyze the mechanical properties. Findings The microstructure of the coatings showed low porosity, oxide content and interface contamination in the substrate–coating interface, without the presence of unmolten particles. The microhardness values reached 600 HV for the three spray distances used and the bond strength values reached over 55 MPa. Practical implications The use of coatings on aircraft components is growing dramatically owing to the high costs of advanced materials and the growing lifecycle requirements for high-performance systems, which are taken into account because of the variety of coatings and complexity of environmental factors. Originality/value The originality of this study lies in the development of new coating materials for the manufacture and protection of various turbine components. The value is based on the development of materials and processes to be used to manufacture them.

Binding Performance of a Zirconia Framework Material and Veneering Porcelain

2010 ◽  
Vol 177 ◽  
pp. 186-189 ◽  
Author(s):  
Long Quan Shao ◽  
Bin Deng ◽  
Yuan Fu Yi ◽  
Qi Liu ◽  
Wei Wei Zhang ◽  
...  
Keyword(s):  
Bond Strength ◽  
Thermal Shock ◽  
Shear Bond Strength ◽  
Chemical Element ◽  
Radial Crack ◽  
Visual Observation ◽  
Thermal Shock Test ◽  
Cross Sectional ◽  
Shock Test ◽  
Cad Cam

In this study, the binding performance of a Cercon-based zirconia framework material and special Cercon Ceram S zirconia veneering porcelain is discussed. Rectangular 30 mm × 20 mm × 2 mm porcelain blocks were made from zirconia using the CAD/CAM system. The 2 mm veneering porcelain was then sintered onto blocks at a temperature of 850-800°C with a loading speed of l mm/min. The shear bond strength of the interface was tested. Sintering was studied by visual observation, scanning electron microscopy, energy dispersive spectroscopy (EDS), thermal shock test and other methods. Excellent sintering results of the zirconia framework material and veneering porcelain can be achieved. The cross-sectional morphology of the samples, observed by SEM, shows a uniform, fine, and smooth texture for the veneering porcelain, whereas that of the zirconia framework material shows a rough surface with a uniform and compact texture. EDS results indicate that a small amount of A12O3 and SiO2 is present in the zirconia area, and no ZrO2 or Y2O3 is detected in the veneering porcelain area. No interlayer radial crack or flaw is found throughout the entire thermal shock test of the samples at 60-240°C. Thus, the cracking temperature of the samples is pegged at T>240°C. The shear bond strength of the interface is 32.62±5.77 MPa. Chemical element infiltration exists between zirconia and the veneering porcelain, indicating the chemical bond between the two. An excellent match between the Cercon-based zirconia framework and the special veneering porcelain can be achieved, which can satisfy clinical requirements.

Development of Nanostructured Al2O3-Ni HVOF Coatings

2006 ◽  
Vol 317-318 ◽  
pp. 539-544 ◽  
Author(s):  
Simo Pekka Hannula ◽  
Erja Turunen ◽  
Jari Keskinen ◽  
Tommi Varis ◽  
Teppo Fält ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Spraying ◽  
Al2o3 Coating ◽  
Hvof Spraying ◽  
Protective Properties ◽  
Hvof Coatings ◽  
Hvof Thermal Spraying ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
Sprayed Coatings

HVOF thermal spraying has been developed to deposit dense Al2O3-coatings for improved protective properties. As compared to generally used plasma sprayed coatings HVOF coatings can be prepared much denser and thus are better suited for applications where protective properties of the coating are needed. In this paper we describe the development of HVOF spraying technologies for nanocrystalline Al2O3- and Al2O3-Ni-coatings. The microstructure and the mechanical properties of these novel coatings are reported and compared to a conventionally processed Al2O3-coating.

Thermal Shock Cracks Initiation and Propagation of WCp / Steel Substrate Surface Composite at 500°C

2011 ◽  
Vol 109 ◽  
pp. 253-260 ◽  
Author(s):  
Ru Qing Huang ◽  
Zu Lai Li ◽  
Ye Hua Jiang ◽  
Rong Zhou ◽  
Fan Gao
Keyword(s):  
Thermal Stress ◽  
Thermal Shock ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Test Method ◽  
Thermal Shock Test ◽  
Transverse Cracks ◽  
Surface Composites ◽  
Initiation And Propagation ◽  
Longitudinal Cracks

In order to provide a theoretical basis for the study of thermal fatigue properties on surface composites, thermal shock cracks initiation and propagation of WCP reinforced high chromium steel substrate surface composites were studied by thermal shock test method at 500 °C. The results show that cracks initiation and propagation begin within a few thermal shock cycles, and after 15 thermal shock cycles, the composites remain intact, indicating a good thermal shock resistance. The thermal shock cracks consist mainly of longitudinal and transverse cracks. Within a few thermal shock cycles, the initiation and propagation of longitudinal cracks play a dominant role; however, with the increase in the number of thermal shock, the transverse cracks may play a key role as the length and number of both types of cracks increases. However, the increase is slow. The longitudinal cracks are mainly caused by the first class thermal stress and the transverse cracks result from the culminant effects of the first and second thermal stress, interacting with each other.

scholarly journals Thermal Shock Behavior and Particle Erosion Resistance of Toughened GZ Coatings Prepared by Atmospheric Plasma Spraying

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1477
Author(s):  
Zining Yang ◽  
Weize Wang ◽  
Shujuan Deng ◽  
Huanjie Fang ◽  
Ting Yang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Thermal Shock ◽  
Plasma Spraying ◽  
Erosion Resistance ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Thermal Shock Test ◽  
Particle Erosion ◽  
Shock Test ◽  
Gadolinium Zirconate

Gadolinium zirconate with excellent high-temperature phase stability and sintering resistance has become a very promising candidate material for a new generation of thermal barrier coatings (TBCs). However, the low fracture toughness of gadolinium zirconate greatly limits its application. In this study, gadolinium zirconate (GZ) and two kinds of toughened gadolinium zirconate (GZ/YSZ prepared by mixed powder of Gd2Zr2O7 and YSZ and GSZC prepared by (Gd0.925Sc0.075)2(Zr0.7Ce0.3)2O7 powder) double-layered TBCs were prepared by atmospheric plasma spraying (APS). The fracture toughness of the GZ/YSZ coating and GSZC coating were 9 times and 3.5 times that of GZ coating, respectively. The results of thermal shock test showed that the three TBCs exhibit different failure mechanisms. During the thermal shock test, cracking occurred at the interfaces between the YSZ layer and the BC or GZ/YSZ layer, while GSZC TBC failed due to premature cracking inside the GSZC layer. The particle erosion rate of the GZ, GZ/YSZ, and GZSC coatings were 1.81, 0.48, and 1.01 mg/g, respectively, indicating that the erosion resistance of coatings is related to their fracture toughness. Furthermore, the superior erosion resistance of the GZ/YSZ and GSZC coatings can be attributed to the conversion of crack propagation path during the erosion test.

scholarly journals High-Temperature Corrosion of APS- and HVOF-Coated Nickel-Based Super Alloy under Air Oxidation and Melted Salt Domains

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5119
Author(s):  
Ibrahim A. Alnaser ◽  
Mohammed Yunus ◽  
Rami Alfattani ◽  
Turki Alamro
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
High Surface ◽  
Thermal Spraying ◽  
Mass Gain ◽  
High Temperature Corrosion ◽  
Atmospheric Plasma ◽  
Air Oxidation ◽  
Hvof Spraying ◽  
High Surface Quality

Various thermal spraying approaches, such as air/atmospheric plasma spraying (APS) and high-velocity oxy-fuel (HVOF) spraying, are widely employed by plants owing to their flexibility, low costs and the high surface quality of the manufactured product. This study focuses on the corrosion behavior of a Ni superalloy coated with powder Cr3C2-25NiCr through APS and HVOF at 950 °C under air oxidation and Na2SO4 + 0.6V2O5 molten salt environments (MSE). The results show that HVOF-deposited Ni superalloys have higher hardness and bond strength than the respective APS coating. The thermo-gravimetric probe reveals that the Ni superalloys exposed to an oxidizing air environment has a minor mass gain compared to those under the MSE domain for both non-coated and coated samples, in line with the parabola curvature rate oxidizing law. The Ni superalloys show good corrosion resistance but poor oxidation resistance in APS-deposited Ni superalloys under the MSE. HVOF-coated Ni superalloys in both environments exhibit better corrosion resistance and lower mass gain than APS-coated superalloys. The excellent coating characteristics of HVOF-coated Ni superalloys lead to their better high-temperature corrosion performance than APS.

Investigation of Thermal Shock Behavior of Plasma-Sprayed NiCoCrAlY/YSZ Thermal Barrier Coatings

2012 ◽  
Vol 472-475 ◽  
pp. 246-250 ◽  
Author(s):  
Hossein Jamali ◽  
Reza Mozafarinia ◽  
Reza Shoja Razavi ◽  
Raheleh Ahmadi Pidani
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Thermal Shock Test ◽  
Barrier Coatings ◽  
Microstructural Evaluation ◽  
Mismatch Stress ◽  
Thermal Shock Behavior ◽  
Plasma Sprayed

ZrO2-8wt.%Y2O3 (8YSZ) thermal barrier coatings (TBCs) were deposited by atmospheric plasma spraying (APS) on NiCoCrAlY-coated Inconel 738LC substrates. The thermal shock behavior was investigated by quenching the samples in water with temperature of 20-25°C from 950°C. To study of failure mechanism results from thermal cycling, microstructural evaluation using scanning electron microscope (SEM), elemental analysis using energy dispersive spectroscopy (EDS) and phasic analysis using x-ray diffractometry (XRD) were done. The results revealed that failure of the TBC system was due to the spallation of ceramic top coat. Thermal mismatch stress was the major factor of TBC failure in thermal shock test.

Fabrication and Properties of APS- and RTS-Sprayed TiB2/Mo2FeB2 Multiphase Ceramic Coating on Q235 Steel

2011 ◽  
Vol 704-705 ◽  
pp. 1244-1252 ◽  
Author(s):  
Xin Ling Guo ◽  
Wei Wang ◽  
Shao Jie Li
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Mass Loss ◽  
Thermal Shock ◽  
Steel Substrate ◽  
Ceramic Coatings ◽  
Atmospheric Plasma ◽  
Composite Powders ◽  
Q235 Steel ◽  
Sprayed Coatings

A kind of TiB2/Mo2FeB2 composite powders for reactive thermal spraying (RTS) and atmospheric plasma spraying (APS) were prepared using Mo powder, Fe-B alloy powder, Fe powder and TiB2 powder. The TiB2/Mo2FeB2 composite ceramic coatings were synthesized and deposited by APS and RTS on Q235 steel. Microstructure and phases were investigated by X-ray diffraction (XRD) and scanning electrical microscopy (SEM). The thermal shock resistance, wear resistance and corrosion resistance were characterized with the relevant lab testing equipment. The result indicates that the coatings are composed of the major phases Mo2FeB2, TiB2 and α-Fe, a little of Fe2O3, FeO, and B2O3.The thermal shock times of RTS-sprayed coatings is 44, the corrosion resistance is 6.07 times than those of the substrate, respectively, while those of APS-sprayed coatings are 55 and 15.5, respectively. The mass loss of Q235 steel is 138.6g/m2, while the mass loss of the coatings with 30% TiB2 which were prepared by RTS is 28.0952g/m2, the mass loss of the coatings with 30% which were prepared by APS is 15.4028g/m2, when the testing load was 400N. Therefore, the coatings with 30%TiB2 prepared by APS possess better wear resistance than the Q235 steel substrate.

scholarly journals Preliminary Studies on HVOF Sprayed Coatings on Magnesium Alloys

2020 ◽  
Vol 2 (1) ◽  
pp. 23
Author(s):  
Ewa Jonda ◽  
Leszek Łatka ◽  
Grzegorz Więcław
Keyword(s):  
Mechanical Properties ◽  
Surface Engineering ◽  
Thermal Spraying ◽  
Life Time ◽  
Good Alternative ◽  
Composition Analysis ◽  
Hvof Spraying ◽  
Foundry Alloys ◽  
Oxygen Fuel ◽  
Sprayed Coatings

In the field of the development of modern techniques, which improve and/or regenerate the component’s surface properties, High Velocity Oxygen Fuel (HVOF) spraying of carbides or metals and their alloys is a good alternative method to other conventional surface engineering ones, including magnesium foundry alloys. Coatings manufactured by thermal spraying are used to improve the durability and life time of machine parts, both the new and regenerated ones, by changing the surface layer properties. In this work the results of HVOF sprayed coatings deposited onto AZ31 magnesium alloy substrate are reported. The feeding material was composite powder Cr3C2–NiCr. The coatings were investigated in terms of their microstructure and selected mechanical properties. For structure examinations, microscopy studies (light and scanning ones) were used as well as phase composition analysis. In the case of mechanical properties, the wear resistance was determined also microhardness was measured.

scholarly journals Fabrication of Roughened Electrodeposited Copper Coating on Steel for Dissimilar Joining of Steel and Thermoplastic Resin

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 591
Author(s):  
Susumu Arai ◽  
Ryosuke Iwashita ◽  
Masahiro Shimizu ◽  
Junki Inoue ◽  
Masaomi Horita ◽  
...  
Keyword(s):  
Shear Strength ◽  
Thermal Shock ◽  
Bonding Strength ◽  
Steel Substrate ◽  
Copper Film ◽  
Copper Coating ◽  
Thermal Shock Test ◽  
Thermoplastic Resin ◽  
Shock Test ◽  
Lap Shear

Electrodeposition of a roughened copper coating onto steel was carried out to produce a bonding surface for thermoplastic resin (polyphenylenesulfide). The roughened copper film was electrodeposited using a copper sulfate bath containing polyacrylic acid (PAA). Following injection molding of the resin, the bonding strength was evaluated in a tensile lap shear strength test, followed by durability testing at high temperature and humidity (85 ± 2 °C and 85 ± 2% relative humidity, respectively) for 2000 h, and a thermal shock test (−50 °C–150 °C) for 1000 cycles. An analysis of the boundary microstructure showed that the PAA concentration had a large effect on the surface morphology of the copper film. The shear strength of the joint between the coated steel substrate and the resin was more than 40 MPa, and the bonding strength also remained above 40 MPa throughout the durability test. During the thermal shock test, although the bonding strength gradually decreased with increasing number of cycles, it remained at over 20 MPa, even after 1000 cycles. This method achieves not only high initial bonding strength, but also durability for joints between dissimilar materials such as steel and resin.

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