scholarly journals Formation of alumina-aluminide coatings on ferritic-martensitic T91 steel

2014 ◽  
Vol 50 (2) ◽  
pp. 165-170 ◽  
Author(s):  
R.K. Choudhary ◽  
V. Kain ◽  
R.C. Hubli
Keyword(s):  
Heat Treatment ◽  
Steel Substrate ◽  
Aluminide Coating ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Imidazolium Chloride ◽  
X Ray ◽  
Aluminide Coatings ◽  
Heat Treated ◽  
Prolonged Heat

In this work, alumina-aluminide coatings were formed on ferritic-martensitic T91 steel substrate. First, coatings of aluminum were deposited electrochemically on T91 steel in a room temperature AlCl3-1-ethyl-3-methyl imidazolium chloride ionic liquid, then the obtained coating was subjected to a two stage heat treatment procedure consisting of prolonged heat treatment of the sample in vacuum at 300 ?C followed by oxidative heat treatment in air at 650 ?C for 16 hours. X-ray diffraction measurement of the oxidatively heat treated samples indicated formation of Fe-Al and Cr-Al intermetallics and presence of amorphous alumina. Energy dispersive X-ray spectroscopy measurement confirmed 50 wt- % O in the oxidized coating. Microscratch adhesion test conducted on alumina-aluminide coating formed on T91 steel substrate showed no major adhesive detachment up to 20 N loads. However, adhesive failure was observed at a few discrete points on the coating along the scratch track.

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.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Ni-B-W-Mo COATING DEPOSITED BY ELECTROLESS METHOD

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Sodium Molybdate ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Heat Treated ◽  
Electroless Coatings

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.

scholarly journals Preparation and Assessment of Heat-Treated α-Chitin Nanowhiskers Reinforced Poly(viny alcohol) Film for Packaging Application

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1883 ◽  
Author(s):  
Chao Peng ◽  
Guangxue Chen
Keyword(s):  
Heat Treatment ◽  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Tests ◽  
Light Transmittance ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Chitin Nanowhiskers

In this study, poly(vinyl alcohol) (PVA) composite films enhanced by α-chitin nanowhiskers (ChWs) were prepared through heat treatment. The obtained membranes were assessed by means of FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, regular light transmittance, mechanical tests, permeability and water absorption. The influence of the nano-component and heat treatment on the mechanical, thermal and water-resistant properties of the composite membrane were analyzed. From the results of the work, the produced films with excellent barrier properties and inexpensive raw processed materials have great prospects in packaging applications.

Magnetization and XRD Studies of Laser Heat Treated SmCo5 Powders

2021 ◽  
Vol 1016 ◽  
pp. 1299-1304
Author(s):  
Naidu Seetala ◽  
Deidre Henderson ◽  
Jumel Jno-Baptiste ◽  
Hao Wen ◽  
Sheng Min Guo
Keyword(s):  
Heat Treatment ◽  
Hydrogen Gas ◽  
Vacuum Furnace ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Particles ◽  
Laser Heat ◽  
Heat Treated ◽  
Xrd Studies ◽  
Hydride Phases

The microstructure and magnetization of SmCo5 micro-particles may be used as feedstock for 3D printing to make miniature strong magnets. Thus, the magnetic response and microstructures of commercially available SmCo5 micro-particles were studied under various heat treatments using a high wattage laser. The magnetization of laser heat treated powders at 50-watt showed an increase in magnetization, while the 75-watt melt showed a little to no change. Unfortunately, the coercivity of both laser heat treated samples decreased significantly. Oxidation during the heat treatment is suspected to result in low coercivity. Purging with argon-gas prior to laser heating showed improved coercivity. To further minimize the oxidation problem a set of SmCo5 powder was reduced prior to laser heat treatment using a constant flow of hydrogen gas while being heated at various temperatures from 100 oC to 400 oC for a period of ~4 hours. The results show that the magnetization generally increases with the temperature, while the coercivity decreases significantly. Another set of SmCo5 was annealed in a vacuum furnace for one hour at temperatures between 200 oC and 400 oC in order to confirm that no hydride phases were formed during reduction. The magnetization and coercivity showed similar variations with annealing temperature to those for the reduced powders confirming that these variations may be due to change in crystal structure rather than formation of hydrides. X-ray Diffraction (XRD) studies were performed to identify the changes in crystal phases.

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.

PREFERABLE ORIENTATION OF CRYSTALLINE THIN-FILM OF MODIFIED BNN SYSTEM

1989 ◽  
Vol 03 (06) ◽  
pp. 465-470 ◽  
Author(s):  
MASAYUKI TSUKIOKA ◽  
TASUKU MASHIO ◽  
MASAJI SHIMAZU ◽  
TAKESHI NAKAMURA
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Stainless Steel ◽  
Steel Substrate ◽  
Rf Sputtering ◽  
Polished Surface ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quantitative Analyses

Using rf-sputtering method, modified BNN ( Ba 2 NaNb 5 O 15) thin-films, which are highly aligned, were prepared on a polished surface of a stainless steel plate and on a polished silicon wafer. It was found that preferably aligned thin-films were successfully obtained only when modified Nb-rich BNN target was used. Preferable orientation of these thin-films was confirmed by X-ray diffraction measurement. In order to find the correlation between preferable orientation and separation from plasma center, X-ray measurement was carried out at several points on the thin-film sputtered on a long stainless steel substrate (5×100 mm ). The result indicated that preferable orientation was dominant near the position of plasma center. In order to distinguish whether the strong X-ray peak observed in the preferably aligned BNN thin-film is due to (200) peak of Nb 2 O 5 or (440) peak of BNN, X-ray measurements and the following quantitative analyses; fluorescent X-ray, ICP (Induced Coupled Radio Frequency Plasma) and an Atomic Absorption Method, were carried out for films sputtered from Nb-rich BNN target. The results reveal that the thin-films include considerable quantity of barium and sodium. This suggests that the highly aligned thin-film is composed of modified BNN and not Nb 2 O 5.

Effect of the Platinum Electroplated Layer Thickness on the Coatings’ Microstructure

2017 ◽  
Vol 36 (3) ◽  
pp. 291-297
Author(s):  
Maryana Zagula-Yavorska ◽  
Kamil Gancarczyk ◽  
Jan Sieniawski
Keyword(s):  
Heat Treatment ◽  
Diffusion Zone ◽  
Roughness Parameter ◽  
Inconel 625 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Inconel 625 Superalloy ◽  
Two Phases ◽  
Electroplating Process

AbstractCMSX 4 and Inconel 625 superalloys were coated by platinum layers (3 and 7 μm thick) in the electroplating process. The heat treatment of platinum layers (at 1,050 ˚C for 2 h) was performed to increase platinum adherence to the superalloys substrate. The diffusion zone obtained on CMSX 4 superalloy (3 and 7 μm platinum thick before heat treatment) consisted of two phases: γ-Ni(Al, Cr) and (Al0.25Pt0.75)Ni3. The diffusion zone obtained on Inconel 625 superalloy (3 μm platinum thick before heat treatment) consisted of the α-Pt(Ni, Cr, Al) phase. Moreover, γ-Ni(Cr, Al) phase was identified. The X-ray diffraction (XRD) results revealed the presence of platinum in the diffusion zone of the heat-treated coating (7 μm platinum thick) on Inconel 625 superalloy. The surface roughness parameter Ra of heat-treated coatings increased with the increase of platinum layers thickness. This was due to the unequal mass flow of platinum and nickel.

Effect of Heat Treatment on the Structure and Morphology of Amorphous Steel Produced Using Spray Metal Forming

2007 ◽  
Vol 539-543 ◽  
pp. 4185-4190
Author(s):  
A. Srinivasa Rao ◽  
L. Kohler ◽  
L.F. Aprigliano
Keyword(s):  
Heat Treatment ◽  
Steel Ingot ◽  
Small Samples ◽  
X Ray Diffraction ◽  
Structure And Morphology ◽  
Heat Treated ◽  
Amorphous Steel ◽  
Electron Microscopes ◽  
Prolonged Heat ◽  
Scanning Electron Microscopes

In order to investigate the effect of heat treatment on the structure and morphology of spray formed structurally amorphous steel, several small samples were cut from one spray formed amorphous steel ingot (DAR – 35). The samples were heat treated at 700oC in a tube furnace under a constant flow of 99.9% argon for up to 120 hours. The samples were furnace cooled to 300oC. Later they were quenched in water. The structure was investigated using x-ray diffraction and the morphology of the polished and lightly etched samples was examined under both optical and scanning electron microscopes. The results indicate that the spray formed steels were amorphous. However, their microstructure is not homogeneous. The microstructure is composed of three distinctively different phase contrasts (viz. light gray, dark gray and bright white contrasts). The bright white phase contained maximum amount of tungsten and molybdenum, it had the least amount of iron. Both light and dark gray phases contained nearly the compositionally expected amount of iron, and more chromium than compositionally expected. The effect of heat treatment at 700oC had no effect on the three different phase contrasts. However, the heat treatment at 700oC showed some effect on the crystallization of the structure. The heat treatment for up to 24 hours has very little effect on the structure and morphology of the amorphous steel samples. However, if the samples were heat treated at 700oC for more than 24 and below 72 hours, it appears that a partial crystallization of the steel occurs. Significant crystallization of the spray formed amorphous steel occurs due to prolonged heat treatment above 72 hours.

Morphology of Carbon Micro-Coils

2004 ◽  
Vol 449-452 ◽  
pp. 205-208
Author(s):  
M. Fujii ◽  
S. Motojima
Keyword(s):  
Heat Treatment ◽  
Lattice Structure ◽  
Diffraction Method ◽  
Chemical Vapor ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Higher Temperature

The double helical carbon micro-coils were obtained by chemical vapor deposition. As-grown carbon micro-coils with amorphous structure were heat-treated at various temperatures up to 3000°C . By heat treatment, the shape of the coils was not changed. The morphology of these coils was observed in detail using electron microscope. The lattice structure was analyzed by X-ray diffraction method. Heat treatment temperature dependence of the magnetoresistance and the measurement of Raman spectra suggest that the coils heattreated at higher temperature are more highly graphitized.

Structures and physical properties of carbon fibers from coal tar mesophase pitch

1987 ◽  
Vol 2 (6) ◽  
pp. 850-857 ◽  
Author(s):  
T. Hamada ◽  
T. Nishida ◽  
Y. Sajiki ◽  
M. Matsumoto ◽  
M. Endo
Keyword(s):  
Heat Treatment ◽  
Carbon Fibers ◽  
Coal Tar ◽  
Transverse Cross Section ◽  
Mesophase Pitch ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transverse Magnetoresistance ◽  
Heat Treated ◽  
Degree Of Graphitization

Carbon fibers having various types of structures were prepared by spinning coal tar mesophase pitch, followed by thermosetting and heat treatment at high temperature. Two kinds of spinning—spinning with stirring the pitch above a capillary and without stirring—have been tried to form pitch fibers from coal tar mesophase pitch. Carbon fibers obtained from mesophase pitch and spun without stirring have a radial transverse structure where the graphite layers are arranged radially in the transverse cross section of the fibers. Carbon fibers made with a stirring system can have random, onion, and a novel “quasionion structure” by changing the spinning conditions. Carbon fibers spun with stirring are less graphitizable than those spun without stirring. No separation of the ten diffraction bands into 100 and 101 peaks and no appearance of a 112 peak were observed by x-ray diffraction when the fibers were heat treated at 2700°C, whereas carbon fibers spun without stirring show clear evidence of graphitization by heat treatment at 2700°C. Transverse magnetoresistance effects at 77 K, (Δρ/ρ)t have been measured to characterize the structure of the carbon fibers. The carbon fibers spun with stirring and heat treated at 2500°C generally exhibit a negative transverse magnetoresistance effect, whereas the carbon fibers spun without stirring exhibit a positive magnetoresistance. Good correlations are found among d002, Lc (002), transverse magnetoresistance, and resistivity at room temperature of carbon fibers spun under various conditions and heat treated at 2500°C. The tensile strengths (TS) of carbon fibers that are less graphitized are higher than those of carbon fibers with a higher degree of graphitization if tensile moduli (TM) are almost constant.

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