ANALYSIS OF PNEUMATIC FINE PARTICLE PEENING PROCESS BY USING A HIGH-SPEED-CAMERA

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3047-3052 ◽  
Author(s):  
TATSUYA ITO ◽  
SHOICHI KIKUCHI ◽  
YO HIROTA ◽  
ATSUSHI SASAGO ◽  
JUN KOMOTORI

In this study, the peening behavior of shot particles in a fine particle peening (FPP) process such as velocity and impact angles were analyzed by using a high-speed-camera. Results showed that the velocity of shot particles depended on a peening pressure; the higher the peening pressure, the higher the particle velocity. The particle velocity measured in this study was approximately 120 m/s; this was much higher than that of the conventional shot peening (SP) process. This was because the air resistance of shot particles in the FPP process was higher than that of shot particles in the SP process. In order to discuss the surface modification effect of the FPP process, commercial-grade pure iron treated by the FPP process was characterized by micro-Vickers hardness tester and scanning electron microscope (SEM). Thickness of hardened layer treated with higher peening pressure was much higher than that of the lower pressure treated one. The unique microstructure with stratification patterns, which was harder than that of the other part, was observed near the specimen surface. The reason for the microstructural changes by the FPP treatment was discussed based on the kinetic energy of shot particles.

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1079
Author(s):  
Penggang Wei ◽  
Liuyi Ren ◽  
Yimin Zhang ◽  
Shenxu Bao

The recovery of fine wolframite is low when using traditional flotation that does not use a microbubble. In this study, a microbubble was introduced into the fine wolframite flotation system; −20 μm wolframite was used as an experiment sample and octyl hydroxamic acid as the collector. The recovery of microbubble flotation reached 84.07%, which is about 12.04% higher than that of traditional flotation. A single-factor flotation experiment, high-speed camera analysis, and SEM (Scanning Electron Microscopy) analysis were used to study the influence of microbubbles on the flotation of fine wolframite. The results show that fine wolframite will more easily agglomerate under the action of microbubbles. The octyl hydroxamic acid adsorbed on the surface of wolframite treated with microbubbles is denser and more abundant.


2014 ◽  
Vol 592-594 ◽  
pp. 1585-1589 ◽  
Author(s):  
K. Kathiresan ◽  
J. Adhavan ◽  
M. Venkatesan

Braking system is one of the important systems in Automobiles. It is essential to decelerate the vehicle and stop it when essential. The temperature of the brake pad (stator) and disc (rotor) increases because of frictional force between them. Higher temperatures may lead to brake fading or failure of braking system. In the present study droplet cooling of commercially available Brake pad is analyzed with surface temperatures in the range of 80°C - 150°C. The brake pad material analyzed is a composite material with Fe2O3, BaO, CaO, SiO2, SO3 and MgO as major constituents. The percentage of the constituents are found using Scanning Electron Microscope (SEM). The brake pad is artificially heated using cartridge heater and a fixed volume of water is dropped on to the brake pad surface using a syringe pump. The characteristics of droplet on the surface of the brake pad are recorded using a High speed camera. The temperature is measured continuously using a K type thermocouple and is recorded using an online data acquisition system. The characteristic of droplet enhanced cooling is presented.


2019 ◽  
Vol 3 ◽  
pp. 2
Author(s):  
Anthony Guillen ◽  
Fang Goh ◽  
Julie Andre ◽  
Amaury Barral ◽  
Clement Brochet ◽  
...  

Sparks ejected by the grinding of steel can be observed to split in mid-flight. In this paper, we investigate the link between steel microstructure and the splitting behavior using two different steels: hypoeutectoid (containing less than 0:8% carbon) and hypereutectoid (>0:8% carbon). We used a high-speed camera filming at 1000 fps to observe the sparks, and a Scanning Electron Microscope to image the microstructures. For the hypoeutectoid steel, we also quantified the splitting behavior of the sparks by measuring the statistical distribution of the linear distance they travel before splitting occurs. We find that our results are coherent with the common explanation of the splitting phenomenon, stating that sparks split because their microstructures allow the formation of pockets of CO2 by oxidation of Fe3C, producing an internal pressure and leading to explosion.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


Author(s):  
M. T. Postek ◽  
A. E. Vladar

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.


Author(s):  
Kazuyuki Koike ◽  
Hideo Matsuyama

Spin-polarized scanning electron microscopy (spin SEM), where the secondary electron spin polarization is used as the image signal, is a novel technique for magnetic domain observation. Since its first development by Koike and Hayakawa in 1984, several laboratories have extensively studied this technique and have greatly improved its capability for data extraction and its range of applications. This paper reviews the progress over the last few years.Almost all the high expectations initially held for spin SEM have been realized. A spatial resolution of several hundreds angstroms has been attained, which is nearly one order of magnitude higher than that of conventional methods for thick samples. Quantitative analysis of magnetization direction has been performed more easily than with conventional methods. Domain observation of the surface of three-dimensional samples has been confirmed to be possible. One of the drawbacks, a long image acquisition time, has been eased by combining highspeed image-signal processing with high speed scanning, although at the cost of image quality. By using spin SEM, the magnetic structure of a 180 degrees surface Neel wall, magnetic thin films, multilayered films, magnetic discs, etc., have been investigated.


Author(s):  
Denys Rozumnyi ◽  
Jan Kotera ◽  
Filip Šroubek ◽  
Jiří Matas

AbstractObjects moving at high speed along complex trajectories often appear in videos, especially videos of sports. Such objects travel a considerable distance during exposure time of a single frame, and therefore, their position in the frame is not well defined. They appear as semi-transparent streaks due to the motion blur and cannot be reliably tracked by general trackers. We propose a novel approach called Tracking by Deblatting based on the observation that motion blur is directly related to the intra-frame trajectory of an object. Blur is estimated by solving two intertwined inverse problems, blind deblurring and image matting, which we call deblatting. By postprocessing, non-causal Tracking by Deblatting estimates continuous, complete, and accurate object trajectories for the whole sequence. Tracked objects are precisely localized with higher temporal resolution than by conventional trackers. Energy minimization by dynamic programming is used to detect abrupt changes of motion, called bounces. High-order polynomials are then fitted to smooth trajectory segments between bounces. The output is a continuous trajectory function that assigns location for every real-valued time stamp from zero to the number of frames. The proposed algorithm was evaluated on a newly created dataset of videos from a high-speed camera using a novel Trajectory-IoU metric that generalizes the traditional Intersection over Union and measures the accuracy of the intra-frame trajectory. The proposed method outperforms the baselines both in recall and trajectory accuracy. Additionally, we show that from the trajectory function precise physical calculations are possible, such as radius, gravity, and sub-frame object velocity. Velocity estimation is compared to the high-speed camera measurements and radars. Results show high performance of the proposed method in terms of Trajectory-IoU, recall, and velocity estimation.


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