INFLUENCE OF TEMPERING ON THE MICROSTRUCTURE PERFORMANCE OF THE LASER-TREATED COATINGS ON 45 STEEL

2013 ◽  
Vol 20 (05) ◽  
pp. 1350048 ◽  
Author(s):  
Xiaodong Hu ◽  
Yajiang Li
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Steel Substrate ◽  
Laser Alloying ◽  
Micro Hardness ◽  
Transmission Electron ◽  
Intensity Transfer ◽  
Scanning Electron

Effect of the tempering on the microstructures and tribological properties of the laser alloying coatings is investigated. Laser alloying of the T - Co 50/ TiC mixed powders on a 45 steel substrate can form a hard composite coating, which increased the micro-hardness and wear resistance of the substrate greatly. Such laser alloying coating was investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Experimental results indicate that the tempering is able to remove the accumulation of the residual stress in a certain extent, improving the plastic and toughness properties of such coating; moreover, tempering also improves greatly the formation mechanism, making the coating have enough ability of the intensity transfer, which is beneficial in preventing the crack propagation of the interface in such coating, leading to an improvement of the wear resistance.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE CHARACTERISTICS OF LASER COMPOSITES

2014 ◽  
Vol 21 (01) ◽  
pp. 1450014
Author(s):  
PENG LIU ◽  
YUANBIN ZHANG ◽  
YAJIANG LI ◽  
QINGQING YANG ◽  
YAN LIU ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Theoretical Basis ◽  
Laser Alloying ◽  
Wear Properties ◽  
Microstructure Characteristics ◽  
Transmission Electron ◽  
Treatment Technologies ◽  
Intensity Transfer ◽  
Scanning Electron

In this paper, effect of heat treatment on the microstructures and wear properties of laser alloying (LA) composites is investigated. LA of the T - Co 50/ FeSi / TiC / TiN / CeO 2 mixed powders on substrate of 45 steel can form the hard composites, which increased the wear resistance of substrate greatly. Such LA composites were investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The tempering promoted the growth of the block-shape hard phases, favoring an enhancement of the integrity of block-shape hard phases; and tempering also improved greatly the formation mechanism, guarantying the composites to have enough ability of intensity transfer. This research provided essential experiment and theoretical basis to promote the application of the laser and heat treatment technologies in the field of surface modification.

MICROSTRUCTURES AND WEAR RESISTANCE OF THE ARGON ARC CLAD NICKEL-BASED COMPOSITES ON TITANIUM ALLOY

2019 ◽  
Vol 26 (08) ◽  
pp. 1950047
Author(s):  
JIANING LI ◽  
MOLIN SU ◽  
LIWEI ZHANG
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Nanoscale Particles ◽  
Amorphous Phases ◽  
Transmission Electron ◽  
Titanium Alloy Substrate ◽  
Scanning Electron

The composites were obtained by the argon-arc cladding (AAC) of the Deloro22-Si3N4-Fe pre-placed powders on a TA1 titanium alloy substrate, which improved the wear resistance of the substrate. Such composites were investigated by means of the scanning electron microscope (SEM), the microscope and the high resolution transmission electron microscope (HRTEM). The results indicated that the amorphous phases were produced in such AAC composites, increasing the wear resistance. With addition of Y2O3, lots of the micro/nanoscale particles were formed, which further improved the wear resistance of such AAC composites.

Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

1971 ◽  
Vol 29 ◽  
pp. 26-27
Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike
Keyword(s):  
Electron Microscope ◽  
Image Quality ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Objective Lens ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

Resolution of a Transmitted Electron Image Formed by A Scanning Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 386-387
Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Specimen Thickness ◽  
Probe Diameter ◽  
Transmission Electron ◽  
Electron Image ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.

Ultrastructure Research of the Gastritis from Returning Bile

1990 ◽  
Vol 48 (3) ◽  
pp. 202-203
Author(s):  
Shaopeng Hu ◽  
Jianhua Wang ◽  
Zhen Li ◽  
Huei Chen ◽  
Fei Cu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gastric Mucosa ◽  
Scanning Electron Microscope ◽  
Lamina Propria ◽  
Transmission Electron Microscope ◽  
Ultrastructural Change ◽  
Common Disease ◽  
Epithelial Surface ◽  
Transmission Electron ◽  
Scanning Electron

Gastritis from returning bile is a common disease, but the reason for the disease is not clear. As the pathologic ultrastructure research progresses, it has drawn attention to the ultrastructural change of cells in gastric mucosa by clinical workers. We observed gastric mucosa tissues of 15 patients suffering from gastritis with a transmission electron microscope (TEM) and a scanning electron microscope (SEM). It is the first report in China that fungus exists in the lamina propria of gastric mucosa tissue. The result is as follows.The gastric mucosa tissues of 15 patients suffering from gastritis were acquired by stomachoscopy. Both TEM and SEM specimens were prepared by the usual methods. Under the TEM, the epithelial surface became higher and larger. Mitochondria of the cells were swollen and cristae were disrupted. There were vacuoles in the cells. The nucleus showed disorder, heterochromatin became darker, and nucleolae could be observed.

Application of Transmission Electron Microscope and Scanning Electron Microscope in experimental tumor studies

1990 ◽  
Vol 48 (3) ◽  
pp. 306-307
Author(s):  
Gao Fengming
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Malignant Transformation ◽  
Transmission Electron Microscope ◽  
Experimental Tumor ◽  
Transmission Electron ◽  
Embryo Cells ◽  
Tumor Studies ◽  
Scanning Electron

Transmission electron microscope(TEM) and scanning electron microscope(SEM) were widely used in experimental tumor studies. They are useful for evaluation of cellular transformation in vitro, classification of histological types of tumors and treating effect of tumors. We have obtained some results as follows:1. Studies on the malignant transformation of mammalian cells in vitro. Syrian golden hamster embryo cells(SGHEC) were transformed in vitro by ThO2 and/or ore dust. In a few days after dust added into medium, some dust crystals were phagocytized. Two weeks later, malignant transformation took place. These cells were of different size, nuclear pleomorphism, numerous ribosomes, increasing of microvilli on cell surface with various length and thickness, and blebs and ruffles(Figs. 1,2). Myelomonocytic leukemic transformation of mouse embryo cells(MEC) was induced in vitro by 3H-TdR. Transformed cells were become round from fusiform. The number of mitochondria and endoplasmic reticulum was reduced, ribosomes and nucleoli increased, shape of nuclei irregular, microvilli increased, and blebs and ruffles appeared(Fig. 3).

A Working Method for Adapting the (SEM) Scanning Electron Microscope to Produce (STEM) Scanning Transmission Electron Microscope Images

2002 ◽  
Author(s):  
Edward Coyne
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Integrated Circuits ◽  
Theoretical Idea ◽  
Cross Sectional ◽  
Additional Advantage ◽  
Transmission Electron ◽  
Resolution Element ◽  
Scanning Electron

Abstract This paper describes the problems encountered and solutions found to the practical objective of developing an imaging technique that would produce a more detailed analysis of IC material structures then a scanning electron microscope. To find a solution to this objective the theoretical idea of converting a standard SEM to produce a STEM image was developed. This solution would enable high magnification, material contrasting, detailed cross sectional analysis of integrated circuits with an ordinary SEM. This would provide a practical and cost effective alternative to Transmission Electron Microscopy (TEM), where the higher TEM accelerating voltages would ultimately yield a more detailed cross sectional image. An additional advantage, developed subsequent to STEM imaging was the use of EDX analysis to perform high-resolution element identification of IC cross sections. High-resolution element identification when used in conjunction with high-resolution STEM images provides an analysis technique that exceeds the capabilities of conventional SEM imaging.

Tribological Properties of PTFE Nanocomposites Filled with Alumina Nanoparticles

2012 ◽  
Vol 557-559 ◽  
pp. 534-537 ◽  
Author(s):  
Yong Ping Niu ◽  
Sa Li ◽  
Jun Kai Zhang ◽  
Li Hua Cai ◽  
Yong Zhen Zhang
Keyword(s):  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tribological Properties ◽  
Wear Behavior ◽  
Alumina Nanoparticles ◽  
Test Rig ◽  
Scanning Electron ◽  
Worn Surfaces

Polytetrafluoroethylene (PTFE) nanocomposites filled with alumina nanoparticles were prepared by compression molding and follow-up sintering. The tribological behaviors of PTFE nanocomposites sliding against GCr15 steel were evaluated using ball-on-disk tribology test rig. The worn surfaces of the unfilled and filled PTFE nanocomposite were investigated using a scanning electron microscope (SEM). The wear behavior of the PTFE nanocomposites was explained in terms of the topography of worn surfaces. It was found that the addition of alumina nanoparticles was effective in enhancing the wear resistance of the PTFE nanocomposite.

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