In this study, the effect of oxygen in shielding gas on material flow behavior weld pool surface was discussed to clarify dominant driving force keyhole plasma arc welding (KPAW). To address issue, convection top observed using a high-speed video camera. The temperature distribution along wall measured two-color pyrometry method confirm Marangoni activity pool. results show that inclination angle (keyhole shape) increased especially near due decrease tension through oxidation when Ar + 0.5%...

Nonwoven fabrics are widely used in the textile manufacturing industry due to their advanced characteristics, such as soft, water-repellent, recycle, ecological, and resilient functions. Nowadays, one of innovated technologies applied bond nonwoven is ultrasonic welding method, advantages afforded by its clean, fast, reliable approach. In this work, isotactic polypropylene (PP) were bonded a continuous process. order consider influence roller on formation joints mechanical properties,...

In the injection molding field, flow of plastic material is one most important issues, especially regarding ability melted to fill thin walls products. To improve melt length, a high mold temperature was applied with pre-heating cavity surface. this paper, we present our research on process by external gas-assisted control. After this, observed an improvement in length into thin-walled products due during filling step. addition, develop heating efficiency, focusing device (FFD) and verified....

Abstract This work investigates the application of ultrasonic vibration to steel joints formed by gas metal arc welding. Welding is done using a active welding source with current 120–160 A, 0.8 mm diameter wire and 10 l min −1 CO 2 flow. The distance from torch horn 120 mm. Ultrasonic most affects weld when position increases penetration speed 190 (275) mm/min for 5 thick (10 thick) plate. Moreover, width Although does not affect hardness zones, it modifies microstructure diffusion...

This paper presents two new methods for estimating the capacitance value of DC-link capacitors single-phase AC/DC PWM converters. At no load condition, a controlled AC current (or voltage) with lower frequency (30Hz) than line is injected into input side, which then causes voltage ripples at DC output side. By extracting voltage, current, and power components on side using digital filters, can be calculated, recursive least squares (RLS) method used. The proposed simply implemented only...

Ultrasonic welding is a method that has been applied for nonwoven fabrics, with many advantages such as fast speed, high reliability, easy automation and especially less pollution to the environment. This paper studies optimization of technological parameters in process time, pressure, weld shape on breaking strength ultrasonic Polypropylene (PP) nonwovens. To evaluate influence level find reasonable domain paper, Taguchi used combination face-centered central composite design (FCCCD)...

In this paper, a radial ultrasonic horn is designed by finite element analysis. Three different modes are obtained corresponding to specific natural frequencies. The distribution of amplitude and stresses resonant mode shape investigated. 7075 aluminum grade utilized for fabricating the horn. sewing machine using established. measured frequencies simulated machined results compared. Two kinds polyvinyl chloride (PVC) tarpaulin fabrics with densities 220 g sqm−1 320 welded welding system....

The material flow dynamic and velocity distribution on the melted domain surface play a crucial role joint quality formation of welding defects. In this study, authors investigated effects low high currents plasma arc thermodynamics molten pool its relationship to high-speed video camera (HSVC) was used observe convection welded-joint appearance. Furthermore, consider Marangoni force activation, temperature measured by thermal HSVC. results revealed that weld higher than inside pool....

Single-point incremental forming (SPIF) has drawn much attention recently due to its flexibility in making parts for rapid prototypes and small samples. Several studies have pointed out the benefits of using ultrasonic vibration (UV) SPIF experimentally. This study verifies effect UV reducing forces by performing numerical simulations. In addition, several process parameters, including tool diameters, rotational speeds, step sizes, amplitudes, is investigated detail. It found that an...

Abstract This study compares ultrasonic-assisted turning to conventional in terms of their effects on surface texture and cutting forces during the machining C45 carbon steel. Experiments were conducted a lathe equipped with 1000 W ultrasonic generator running at 20 kHz. Ultrasonic-assisted results small, evenly distributed spherical scratches workpiece, while leads long, uneven marks. Significantly, achieves notably smoother finish than turning. As depth cut increases, causes increasingly...

A parabolic, multilayer x-ray mirror, which can be used with a general lab-based source, was designed and fabricated. glass substrate for the mirror Its surface determined by following rotation of parabolic curve polished precisely. On surface, six W/Al bilayers were deposited to form mirror. The effects on images investigated based calculated modulation transfer function (MTF) image intensity values. Higher MTF values an obtained using

Abstract An ultrasonic horn operated at 28 kHz was simulated by finite element analysis. The horns and samples were formed from hypoeutectoid steel containing 0.178 wt% C 1.3 Cr. They austenized 875 °C with a soaking time of 33 min, then quickly water-quenched oil-quenched. Tempering performed different temperatures (200 °C–500 °C) times (120–240 min). Over the cross-section, hardness consistently lower center position than other positions. maximum (minimum) achieved after water oil...

An anode exchangeable X-ray tube of very simple structure was developed. Aluminum, chromium, and copper targets were prepared used to investigate spectra. images a thin wood plate taken using those targets. The measured energies the characteristic X-rays each target agreed well with presented results. difference resolution brightness image found based on MTF values intensities. developed can give high durability, higher quality an arbitrary object by exchanging

This study explores the optimization of ultrasonic horn heat treatment conditions for enhanced mechanical quality (Q m ). The optimal parameters identified are a tempering temperature 529°C and 240-min soaking time, yielding 1.3% experimental error. Frequency stability during welding is significantly improved, with exhibiting minimal frequency variation 64 Hz compared to 90 82 other samples. Hardness varies temperature, reaching peak over 39.3 HRC at 450°C dropping 23.8 650°C....

Obecnie do monitorowania przemieszczeń powszechnie stosuje się techniki Globalnego Systemu Nawigacji Satelitarnej (GNSS). Niniejsza praca stanowi przegląd aktualnego rozwoju zastosowań technologii GNSS wyznaczania na podstawie wniosków z 50 publikacji naukowych ostatnich piętnastu lat, od 2009 r. sierpnia 2024 Uzyskane wyniki wskazują, że RTK-GNSS i PPP-GNSS są skuteczne metody deformacji, osiadań osuwisk terenach górniczych kopalni odkrywkowych, podziemnych, opuszczonych kopalniach...

Nonwoven fabrics have been widely used in textile manufacturing industry as a sheet or web structure because of soft, water-repellent, recycle, ecological and resilient functions. Ultrasonic welding method has applied for bonding nonwoven due to clean, fast reliable approach. In this work, the ultrasonic stepped horn is designed generate uniform amplitudes on working surface by using finite element analysis (FEA) simulation. Chromium carbon steels are utilized produce horns high wear...

The material flow dynamic and velocity distribution on the melted domain surface play a crucial role joint quality formation of welding defects. In this study, authors investigated effects low high currents plasma arc thermodynamics molten pool its relationship to high-speed video camera (HSVC) was used observe convection welded-joint appearance. Furthermore, consider Marangoni force activation, temperature measured by thermal HSVC. results revealed that weld higher than inside due...

A multilayered parabolic mirror with six W/Al bilayers was designed and fabricated to generate monochromatic parallel x-rays using a lab-based x-ray source. Using this mirror, curved bright bands were obtained in images as reflected x-rays. The parallelism of the investigated shape bands. intensity characteristics evaluated through measurements spectra band. High intensity, nearly monochromatic, x-rays, which can be used for high resolution microscopes local radiation therapy systems, obtained.

This investigation aims to discuss the formation process of eddies and heat transportation in plasma keyhole arc welding. In order clarify this issue, measurement convection inside weld pool, on pool surface, also temperature distribution surface were carried out. The results showed that two found which is controlled mainly through shear force by flow acting surface. magnitude, extent direction are thought be determined primarily variation profile. relative shape strength each eddy largely...

The microstructure of the weld influences its quality, in which grain size is one most important parameters affecting mechanical properties weld. To change size, cooling process zone must be carefully controlled. Customarily, cooled down without post-treatment after welding process, so similar to that casting. In this study, ultrasonic vibrations are used from beginning until part completely cooled. Using waves with frequency 20kHz, power 1500W, researchers analyzed microstructure, comparing...

We demonstrate the potential of neutron systems for detecting microscale defects in a thin epoxy adhesive layer between two metal plates. Neutron tomography has been used to ascertain internal structure layer. The distribution including microvoids is found three-dimensionally reconstructed models that are obtained from images and compared with magnified real image From results, we find system can be most suitable tool lies high X-ray attenuation