In situmonitoring of material processing by a pulsed laser beam coupled via a lensed fiber into a scanning electron microscope

2008 ◽  
Vol 26 (6) ◽  
pp. 1432-1438 ◽  
Author(s):  
David J. Hwang ◽  
Nipun Misra ◽  
Costas P. Grigoropoulos ◽  
Andrew M. Minor ◽  
Samuel S. Mao
2021 ◽  
Author(s):  
Ketema Bobe Bonsa ◽  
Moera Gutu Jiru ◽  
BALKESHWAR SINGH ◽  
Tewodros Derese Gidebo

Abstract Chemo mechanical laser beam assisted finishing is the process of a conceptual combination of a fundamental cognitive process. In this process, three basic concepts are synthesized to obtain a smooth surface of silicon carbide. Three different chemicals of H2SO4 , HCl, and HF with a 50% solution with purified water were used. Continuous mode CO2 power from 250W-300W was used to melt the surface after acid was applied. The smooth surface was evaluated using morphology, including pore pattern, pore depth, and pore width was studied under a scanning electron microscope, and the surface roughness, wear-resistance, and hardness were analyzed using a non-contact surface profilometer, scratch tester TR-101, and Digital Rockwell hardness device respectively. The results were statistically analyzed using Design expert software analysis of variance (ANOVA). The results showed a significant change in the pore pattern, crystal structure, surface roughness, wear-resistance, and hardness. This result was verified by scanning electron microscope, optical microscope, Non-contact profilometer, and scratch tester TR-101machine. The hardness of the smooth surface was increased as well as surface roughness and the coefficient of friction also improved as compared to substrate silicon carbide.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2201
Author(s):  
Daizen Nakamura ◽  
Naoto Koshizaki ◽  
Nobuyuki Shishido ◽  
Shoji Kamiya ◽  
Yoshie Ishikawa

Generally, hard ceramic carbide particles, such as B4C and TiC, are angulated, and particle size control below the micrometer scale is difficult owing to their hardness. However, submicrometer particles (SMPs) with spherical shape can be experimentally fabricated, even for hard carbides, via instantaneous pulsed laser heating of raw particles dispersed in a liquid (pulsed laser melting in liquid). The spherical shape of the particles is important for mechanical applications as it can directly transfer the mechanical force without any loss from one side to the other. To evaluate the potential of such particles for mechanical applications, SMPs were compressed on various substrates using a diamond tip in a scanning electron microscope. The mechanical behaviors of SMPs were then examined from the obtained load–displacement curves. Particles were fractured on hard substrates, such as SiC, and fracture strength was estimated to be in the GPa range, which is larger than their corresponding bulk bending strength and is 10–40% of their ideal strength, as calculated using the density-functional theory. Contrarily, particles can be embedded into soft substrates, such as Si and Al, and the local hardness of the substrate can be estimated from the load–displacement curves as a nanoscale Brinell hardness measurement.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

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.


Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto

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.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Sign in / Sign up

Export Citation Format

Share Document