The Effect of Tungsten Addition on the Thermal Stability and Microstructure in the Electroless Ni-P-W Composite Coating

2006 ◽  
Vol 313 ◽  
pp. 83-90 ◽  
Author(s):  
Shih Kang Tien ◽  
Fan Bean Wu ◽  
Jenq Gong Duh
Keyword(s):  
Steel Substrate ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Transmission Electron ◽  
Heat Treated ◽  
Differential Scanning Calorimeter Analysis ◽  
Electroless Process ◽  
Electroless Ni ◽  
Heat Treated Temperature

Ni-P-W composite deposit on the mild steel substrate was derived by the electroless process. The composition of the eletroless coating was Ni-10.7wt.%P-8.7wt%W analyzed by electron probe microanalysis (EPMA). The coating was annealed at various temperatures from 350oC to 600oC for 4h and the structure at different heat-treated temperature was studied by X-ray diffraction, and transmission electron microscope (TEM). The crystallization behavior was evaluated by the differential scanning calorimeter analysis with continuously heating from room temperature to 550oC at different heating rates. The hardness at all depths of the coating on the substrate could be acquired by the nanoindentation. From the DSC analysis, the onset temperature and crystallization temperature were 397.7oC and 405.5oC, respectively, at the heating rate of 10oC/min. The activation energy of the Ni-P-W coating was 307 kJ/mol analyzed by Kissinger, and Augis and Bennett methods with different heating rates. The Ni-P-W coating showed an amorphous structure in the as-deposited state and exhibited a relatively low hardness of approximately 6.8 GPa. As temperature was raised to 380oC, the hardness was slightly increased to 8.7 GPa due to the partial precipitation of Ni and Ni3P in the amorphous matrix. On heating to 500oC for 4 h, the hardness reached the maximum value of 12.3 GPa with a grain size of 33.1 nm and followed by gradual degradation above 500oC.

Influence of Heat Treated Temperature on the Photoactivating Property of Nanometer ZnO/SnO2 Powder

2012 ◽  
Vol 182-183 ◽  
pp. 126-129
Author(s):  
Xin You Huang ◽  
Chun Hua Gao ◽  
Zhi Gang Chen
Keyword(s):  
Raw Materials ◽  
Methyl Orange Solution ◽  
Reaction Model ◽  
X Ray Diffraction ◽  
Maximum Particle Size ◽  
Transmission Electron ◽  
Heat Treated ◽  
Maximum Particle ◽  
Heat Treated Temperature ◽  
Orange Solution

Nanometer ZnO/SnO2powder was prepared by coprecipitating method with SnCl4•5H2O, ZnNO3•6H2O, HCl, NaOH as raw materials. Influence of heat treated temperature on the photoactivating property and structure and material phase of nanometer ZnO/SnO2(ZnO/SnO2=4/1(mol ratio)) compound photocatalyst powder was studied by X-ray diffraction (XRD) and transmission electron microscope(TEM) and the degradation of methyl orange solution as a reaction model. The results show that the photoactivating activity of ZnO/SnO2powder starts increasing and then decreasing when heat treated temperature increases. The photoactivating activity of ZnO/SnO2powder is maximum, particle size is 20-30 nanometer and dispersion is good when heat treated temperature is 650°C. The photocatalytic activity of ZnO/SnO2powder gradually reduces, dispersion is not good and there is Zn2SnO4crystal phase when heat treated temperature is above 750°C.

Microstructure and Wear Behavior of Thermally Sprayed Fe-Based Amorphous Coating

2007 ◽  
Vol 353-358 ◽  
pp. 848-851 ◽  
Author(s):  
Yeong Sik Kim ◽  
Kyun Tak Kim ◽  
Byung Tak Kim ◽  
Jong Il Bae
Keyword(s):  
Wear Behavior ◽  
Steel Substrate ◽  
Dry Sliding Wear ◽  
Amorphous Coating ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Thermally Sprayed ◽  
Amorphous Coatings ◽  
Wear Tests

In this study, microstructure and wear behavior of thermally sprayed Fe-based alloy coatings were investigated. Fe-based alloy coatings were formed on a carbon steel substrate and then heat-treated at temperature of 700 oC for 20 minutes. Dry sliding wear tests were performed using the sliding speeds of 0.4 and 0.8 m/s, the applied loads of 3 and 6 N. Microstructure and wear behavior of as-sprayed and heat-treated Fe-based amorphous coatings were studied using a scanning electron microscope(SEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD).

Devitrification products of rapidly solidified Ni-Nb amorphous alloys.

1990 ◽  
Vol 48 (4) ◽  
pp. 950-951
Author(s):  
G. A. Bertero ◽  
W.H. Hofmeister ◽  
N.D. Evans ◽  
J.E. Wittig ◽  
R.J. Bayuzick
Keyword(s):  
Electron Microscopy ◽  
Amorphous Structure ◽  
Sulphuric Acid Solution ◽  
X Ray Diffraction ◽  
High Fracture ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Rapidly Solidified ◽  
Electromagnetically Levitated

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

scholarly journals A Study of Thin Film Resistors Prepared Using Ni-Cr-Si-Al-Ta High Entropy Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ruei-Cheng Lin ◽  
Tai-Kuang Lee ◽  
Der-Ho Wu ◽  
Ying-Chieh Lee
Keyword(s):  
Annealing Temperature ◽  
Phase Evolution ◽  
Amorphous Structure ◽  
High Entropy Alloy ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Thin Film Resistors

Ni-Cr-Si-Al-Ta resistive thin films were prepared on glass and Al2O3substrates by DC magnetron cosputtering from targets of Ni0.35-Cr0.25-Si0.2-Al0.2casting alloy and Ta metal. Electrical properties and microstructures of Ni-Cr-Si-Al-Ta films under different sputtering powers and annealing temperatures were investigated. The phase evolution, microstructure, and composition of Ni-Cr-Si-Al-Ta films were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Auger electron spectroscopy (AES). When the annealing temperature was set to 300°C, the Ni-Cr-Si-Al-Ta films with an amorphous structure were observed. When the annealing temperature was at 500°C, the Ni-Cr-Si-Al-Ta films crystallized into Al0.9Ni4.22, Cr2Ta, and Ta5Si3phases. The Ni-Cr-Si-Al-Ta films deposited at 100 W and annealed at 300°C which exhibited the higher resistivity 2215 μΩ-cm with −10 ppm/°C of temperature coefficient of resistance (TCR).

New method for the production of bulk amorphous materials of Nd–Fe–B alloys

2005 ◽  
Vol 20 (3) ◽  
pp. 563-566 ◽  
Author(s):  
Tetsuji Saito ◽  
Hiroyuku Takeishi ◽  
Noboru Nakayama
Keyword(s):  
Electron Microscopy ◽  
Amorphous Materials ◽  
Room Temperature ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
Melt Spun Ribbons

We report a new compression shearing method for the production of bulk amorphous materials. In this study, amorphous Nd–Fe–B melt-spun ribbons were successfully consolidated into bulk form at room temperature by the compression shearing method. X-ray diffraction and transmission electron microscopy studies revealed that the amorphous structure was well maintained in the bulk materials. The resultant bulk materials exhibited the same magnetic properties as the original amorphous Nd–Fe–B materials.

Tribological Performance Optimization of Electroless Nickel Coatings Under Lubricated Condition

2018 ◽  
pp. 250-280 ◽  
Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo
Keyword(s):  
Performance Optimization ◽  
Friction And Wear ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Wear Depth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Electroless Ni ◽  
Scanning Electron

The present chapter aims to determine optimal tribo-testing condition for minimum coefficient of friction and wear depth of electroless Ni-P, Ni-P-W and Ni-P-Cu coatings under lubrication using grey relational analysis. Electroless Ni-P, Ni-P-W and Ni-P-Cu coatings are deposited on AISI 1040 steel substrates. They are heat treated at suitable temperatures to improve their hardness. Coating characterization is done using scanning electron microscope, energy dispersive X-Ray analysis and X-Ray diffraction techniques. Typical nodulated surface morphology is observed in the scanning electron micrographs of all the three coatings. Phase transformation on heat treating the deposits is captured through the use of X-Ray diffraction technique. Vicker's microhardness of the coatings in their as-deposited and heat treated condition is determined. Ni-P-W coatings are seen to exhibit the highest microhardness. Friction and wear tests under lubricated condition are carried out following Taguchi's experimental design principle. Finally, the predominating wear mechanism of the coatings is discussed.

Microstructures and Properties of Fe/B-Fe Coating Used in Circulating Fluidized Bed Boiler

2011 ◽  
Vol 66-68 ◽  
pp. 1528-1532
Author(s):  
Qi Fa Tian ◽  
Hong Fei Sun
Keyword(s):  
Electron Probe ◽  
Circulating Fluidized Bed ◽  
Steel Substrate ◽  
Electric Arc ◽  
Bare Metal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Mechanical Performances ◽  
Electronic Microscope

Electric arc praying technology was used to produce Fe/B-Fe coating on the carbon steel substrate. The microstructures was studied by means of scanning electronic microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and electron probe microanalysis (EPMA). Mechanical performances, wear resistance of coating were tested . The results showed that the resistance to abrasion and corrosion of Fe/B-Fe coating was respectively 16 times and 5 to 6 times higher than those of bare metal.

Copper(I) Halide Nanoparticle-dispersed Glasses Prepared by Copper Staining

2005 ◽  
Vol 20 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Kohei Kadono ◽  
Tatsuya Suetsugu ◽  
Takeshi Ohtani ◽  
Toshihiko Einishi ◽  
Takashi Tarumi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Surface Region ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Heat Treated ◽  
Glass Heat

Copper(I) chloride and bromide nanoparticle-dispersed glasses were prepared by means of a conventional copper staining. The staining was performed by the following process: copper stain was applied on the surfaces of Cl−- or Br−-ion-containing borosilicate glasses, and the glasses were heat-treated at 510 °C for various times. Typical exciton bands observed in the absorption spectra of the glasses after the heat treatment indicated that CuCl and CuBr particles were formed in the surface region of the glasses. The average sizes of the CuCl and CuBr particles in the glasses heat-treated for 48 h were estimated at 4.8 and 2.7 nm, respectively. The nanoparticles were also characterized by x-ray diffraction and transmission electron microscopy. Depth profiles of Cu and CuBr concentration in the glass heat-treated for 48 h were measured. Copper decreased in concentration monotonously with depth, reaching up to 60 μm, while the CuBr concentration had a maximum at about 25 μm in depth.

Effect of temperature on formation of murataite and murataite-pyrochlore ceramics

2002 ◽  
Vol 757 ◽  
Author(s):  
O. I. Kirjanova ◽  
S. V. Stefanovsky ◽  
S. V. Yudintsev
Keyword(s):  
Effect Of Temperature ◽  
Cold Crucible ◽  
Iron Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Solid Solution ◽  
Transmission Electron ◽  
Heat Treated ◽  
Unit Cells ◽  
Fluorite Type

ABSTRACTProcesses of phases formation in the ceramic mixtures with basic compositions (wt.%) 10 CaO, 10 MnO, 5 Al2O3, 5 Fe2O3, 55 TiO2, 5 ZrO2, 10 UO2 (M1) and 8 CaO, 8 MnO, 4 Al2O3, 4 Fe2O3, 20 Gd2O3, 44 TiO2, 4 ZrO2, 8 UO2 (M4) were studied using X-ray diffraction, scanning and transmission electron microscopy. The batches were milled, compacted in pellets at 200 MPa, and heat-treated in a resistive furnace at 1100 °C, 1300 °C, 1400 °C, and 1500 °C as well as melted in a cold crucible at ∼1600 °C. Reactions in the mixtures heat-treated at 1100 °C were not completed and samples contained significant amount of unreacted and intermediate (altered rutile, cubic oxide solid solution, perovskite) phases. Within the temperature range 1100–1300 °C reactions are mainly completed and ceramics sintered at 1300 °C are composed of major murataite and minor rutile (M1) or major murataite and pyrochlore and minor zirconolite and perovskite (M4). However full homogenization at 1300 °C has not been reached yet and to obtain the ceramics with uniform compositions of the phases sintering at 1400 °C or melting at 1500–1600 °C were required.In the ceramic sample M1 two murataite varieties with five- (murataite-5C) and eight-fold (mu-rataite-8C) fluorite-type unit cells were found. The sample M4 is composed of pyrochlore, murataite-8C and zirconolite-3O. In the sample M1 murataite-5C is enriched with U and Ca and depleted with iron group elements as compared to murataite-8C. Fraction of murataite-5C concentrates about 80% of total U and about 70% of Mn+Fe (corrosion products). Waste elements partitioning among the phases in the M4 sample depends significantly on temperature of heat-treatment.

Low Temperature Synthesis and Characterization of CaO and MgO- Stabilized Nanocrystalline Tetragonal Zirconia by Citrate Gel Process

2008 ◽  
Vol 368-372 ◽  
pp. 754-757
Author(s):  
Hasan Gocmez ◽  
Hirotaka Fujimori
Keyword(s):  
Single Phase ◽  
Tetragonal Zirconia ◽  
Xrd Analysis ◽  
Complex Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Crystallite Sizes ◽  
Citrate Gel Process

The citrate gel method, similar to the polymerized complex method, was used to synthesize homogenous tetragonal zirconia at 800oC and 1000oC. Nanocrystalline tetragonal single phase has been fully stabilized with 3, 7, 10 mol% CaO and 10, 15 mol% MgO at 800oC, respectively. In addition, the XRD analysis showed the absence of monoclinic phase after addition of 7 and 10 mol% CaO into zirconia-based solid solutions, which have been fully stabilized both 800oC and 1000oC. The crystallite sizes of the t-ZrO2 with 3, 7 and 10 mol% CaO at 1000oC were 32, 28 and 29nm, respectively. For ZrO2- x mol% MgO (x=3, 10, 15) solid solution, the crystallite sizes of samples at 800oC were less than 29nm, however it was increased up to 69nm at 1000oC. The prepared gel and subsequent heat-treated powders were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) to get detail information regarding to differentiation of polymorphs of zirconia as well as formation of powders.

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