Hardness Test and Microscopic Evaluation of Carbidic HVOF Spray Coatings

2019 ◽  
Vol 56 (11) ◽  
pp. 719-730
Author(s):  
H. Schnarr ◽  
W. Motl
Keyword(s):  
Hardness Test ◽  
Spray Coatings ◽  
Hvof Spray ◽  
Microscopic Evaluation

Optimized multiaxis robot kinematic for HVOF spray coatings on complex shaped substrates

2006 ◽  
Vol 201 (5) ◽  
pp. 2065-2071 ◽  
Author(s):  
Antonio Candel ◽  
Rainer Gadow
Keyword(s):  
Spray Coatings ◽  
Hvof Spray

Thermal Shock Performance of Al2O3/TiO2 Air Plasma Spray Coatings

2011 ◽  
Vol 328-330 ◽  
pp. 853-856 ◽  
Author(s):  
Sun Hui Yao ◽  
Yan Liang Su ◽  
Wen Xian Kao
Keyword(s):  
Thermal Shock ◽  
Plasma Spray ◽  
Hardness Test ◽  
Thermal Shock Test ◽  
Air Plasma Spray ◽  
Air Plasma ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
Quenching Method ◽  
Coating Hardness

This study aimed to understand the effect of TiO2 content on the thermal shock performance of Al2O3/TiO2 air plasma spray coatings. Three kinds of commercial feedstock powders were used, i.e. Al2O3, Al2O3-13wt%TiO2 and Al2O3-40wt%TiO2. The resulting coatings were studied in terms of micro Vickers hardness test, XRD, SEM and thermal shock test. The last was conducted using a water quenching method. The results showed that both the coating hardness and thermal shock performance decreased with the TiO2 content.

Vacuum arc velocity and erosion rate measurements on nanostructured plasma and HVOF spray coatings

2007 ◽  
Vol 40 (14) ◽  
pp. 4192-4201 ◽  
Author(s):  
Lakshminarayana Rao ◽  
Richard J Munz ◽  
Jean-Luc Meunier
Keyword(s):  
Erosion Rate ◽  
Vacuum Arc ◽  
Spray Coatings ◽  
Hvof Spray

A Study on Thermal Spray Coatings of Recuperators

1996 ◽  
Author(s):  
B.G. Seong ◽  
S.Y. Hwang
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Molten Salt ◽  
High Temperature Corrosion ◽  
Maximum Temperature ◽  
Corrosion Mechanism ◽  
Spray Coatings ◽  
Arc Spray ◽  
Salt Corrosion ◽  
Hvof Spray

Abstract High temperature corrosion is a serious problem on tlie heat exchanger tubes of recuperators because they encounter an corrosive environment at maximum temperature around 900°C. These tubes were found to be corroded via oxidation, sulfidation and molten salt corrosion. Particularly molten salt corrosion could be the most severe corrosion mechanism. As a protective coating for recuperators, nickel and cobalt based self-fluxing alloys, iron based amorphous alloy and chromium carbide cermet coatings were considered. These coatings were prepared by an arc spray and or/not fusing or a HVOF spray. Their molten salt corrosion resistance was tested, and the high temperature corrosion resistance in a SO2 containing atmosphere was examined. Also microstructures of the coatings were studied after corrosion tests.

A study on the adhesion of the HVOF spray coatings

2004 ◽  
Vol 2004 (0) ◽  
pp. 227-228
Author(s):  
Kensuke Yokoyama ◽  
Yoshihiko Gotou ◽  
Seiji Kuroda ◽  
Tadanobu Inoue
Keyword(s):  
Spray Coatings ◽  
Hvof Spray

Current Activities for Standardization of Test Method for Interfacial Fracture Toughness of Thermal Spray Coatings in Japan

2013 ◽  
Vol 577-578 ◽  
pp. 149-152
Author(s):  
Masayuki Arai ◽  
Yasuhiro Yamazaki ◽  
Masato Suzuki ◽  
Yukio Miyashita ◽  
H. Waki
Keyword(s):  
Fracture Toughness ◽  
Thermal Spray ◽  
Indentation Test ◽  
Hardness Test ◽  
Interfacial Fracture ◽  
Standard Test ◽  
Test Method ◽  
Test Machine ◽  
Interfacial Fracture Toughness ◽  
Spray Coatings

Collaborative research has been conducted by the Japan Thermal Spray Society (JTSS) to establish a standard test method for evaluating the interfacial fracture toughness of thermal sprayed coatings, including thermal barrier coatings. The test method is based upon the indentation test method utilizing a conventional Vickers hardness test machine. In this committee, round robin tests were performed to check differences in the evaluated results among collaborators. This paper reports on the progress of such activity in Japan.

Investigation and Analysis of Wear Reduction in Piston Rings through Coating

2015 ◽  
Vol 813-814 ◽  
pp. 874-879
Author(s):  
P. Jayanth ◽  
E. Sangeeth Kumar
Keyword(s):  
Plasma Spray ◽  
Piston Ring ◽  
Engine Performance ◽  
Spray Coating ◽  
Hardness Test ◽  
Barrier Properties ◽  
Piston Rings ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
Wear Reduction

In this study, the surface of a Piston Ring in the engine is coated with multilayered coating powder using plasma-spray technique, and its surface behavior is subsequently analyzed. The purpose of this study is to analyze the mechanical and thermal effects of surface coating for a Piston Ring during friction. Here specimens with and without coatings were prepared and then microstructure, hardness and corrosion tests were carried out. From the experimental results and Ansys results, it has been found that the coated specimen has improved the properties in improving the diesel engine performance. The results show less deformation and fewer scratches due to wear on the multilayer coated Piston Ring as compared to the uncoated one. The surfaces topography and the structure of the plasma spray coatings is observed on the scanning Electron microscope. The evaluation of the adhesion of coatings is made using the hardness test and also compared using the thermal barrier properties. Taking into account the results of measurements, one can state that the lowest wear and thermal resistance on piston rings by plasma spray coating.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Selection and Preparation of Specific Tissue Regions For Tem Using Large Epoxy-Embedded Blocks

1973 ◽  
Vol 31 ◽  
pp. 324-325 ◽  
Author(s):  
P. M. Lowrie ◽  
W. S. Tyler
Keyword(s):  
Electron Microscopy ◽  
Anatomical Structures ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Embedded Blocks ◽  
Specific Tissue ◽  
Definition Of ◽  
Areas Of Interest ◽  
Selection Of

The importance of examining stained 1 to 2μ plastic sections by light microscopy has long been recognized, both for increased definition of many histologic features and for selection of specimen samples to be used in ultrastructural studies. Selection of specimens with specific orien ation relative to anatomical structures becomes of critical importance in ultrastructural investigations of organs such as the lung. The uantity of blocks necessary to locate special areas of interest by random sampling is large, however, and the method is lacking in precision. Several methods have been described for selection of specific areas for electron microscopy using light microscopic evaluation of paraffin, epoxy-infiltrated, or epoxy-embedded large blocks from which thick sections were cut. Selected areas from these thick sections were subsequently removed and re-embedded or attached to blank precasted blocks and resectioned for transmission electron microscopy (TEM).

TEM comparison of osmium vs osmium with potassium ferricyanide secondary fixatives and the impact of secondary fixative temperature on tissue preservation/contrast quality

1996 ◽  
Vol 54 ◽  
pp. 910-911
Author(s):  
J. W. Horn ◽  
B. J. Dovey-Hartman ◽  
V. P. Meador
Keyword(s):  
Osmium Tetroxide ◽  
Potassium Ferricyanide ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Cacodylate Buffer ◽  
Transmission Electron Microscopic ◽  
Glutaraldehyde Solution ◽  
Temperature Impact ◽  
The Impact

Osmium tetroxide (OsO4) is a universally used secondary fixative for routine transmission electron microscopic evaluation of biological specimens. Use of OsO4 results in good ultrastructural preservation and electron density but several factors, such as concentration, length of exposure, and temperature, impact overall results. Potassium ferricyanide, an additive used primarily in combination with OsO4, has mainly been used to enhance the contrast of lipids, glycogen, cell membranes, and membranous organelles. The purpose of this project was to compare the secondary fixative solutions, OsO4 vs. OsO4 with potassium ferricyanide, and secondary fixative temperature for determining which combination gives optimal ultrastructural fixation and enhanced organelle staining/contrast.Fresh rat liver samples were diced to ∼1 mm3 blocks, placed into porous processing capsules/baskets, preserved in buffered 2% formaldehyde/2.5% glutaraldehyde solution, and rinsed with 0.12 M cacodylate buffer (pH 7.2). Tissue processing capsules were separated (3 capsules/secondary fixative.solution) and secondarily fixed (table) for 90 minutes. Tissues were buffer rinsed, dehydrated with ascending concentrations of ethanol solutions, infiltrated, and embedded in epoxy resin.

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