Papers by Keyword: PiN

Abstract: In this work, we investigate the static electrical parameters of 1200 V 4H-SiC power diodes with various designs and architectures (Schottky, PiN, and JBS with hexagonal or stripes anode), fabricated on two types of 150 mm substrates (single crystal 4H-SiC reference and 3C-poly silicon carbide based substrates: SmartSiC^TM). I(V) measurements are carried out in both reverse and forward modes to assess the impact of designs and substrates. Non-destructive avalanche mode is reached with similar performance (leakage, V_AV) observed for both substrates (due to identical drift layers and device structures). All diode designs on SmartSiC^TM exhibit a larger current conduction and less resistance in the ohmic regime (compared to bulk), whatever the temperature (up to 200°C). Partitioning model is also proposed for evaluating the substrate contribution on the measured specific resistance and on the observed SmartSiC^TM gains.

Abstract: A hexagonal shaped repeated loop structure with reconfigurable ground stub technique is proposed for ultra-wideband (UWB) application. Effects of repeated loops in the fractal structure and position of reconfigurable ground stub are optimized for ultra-wideband characteristics with better performance of the antenna. Two PIN diodes are used in the ground stub to achieve reconfigurability. The proposed fractal antenna is designed with FR4 substrate with an overall dimension of 40×44×1.6 mm³. The design shows frequency reconfiguration from Ultra-wideband characteristics to multiband for different possible switching conditions. The entire design is carried out in CST 2018 environment and the simulated results show that the proposed design is suitable for sub 6GHz wireless LAN, Bluetooth, WiMAX and other wireless applications.

Abstract: Friction stir welding is a solid-phase welding process based on the mixing of the pasty material in the stirred zone. The main advantage of this technique is the ability to weld metal alloys which are generally difficult to weld by conventional welding processes. In this paper an analytical model is proposed for the description in 2D the distribution of the material (fluid) flow in the vicinity of the tool pin during friction stir welding process "FSW". For this reason, the analytical solutions are built on the basis of traditional problem of mechanics of the fluids which is used to solve the equation associated with this problem. Furthermore, the aim is to make an analytical study of these aspects for a better understanding of this phenomenon. This method provides a reduction in computational time compared to those required for finite or differential elements methods. Moreover, it highlights on the effects of the different parameters on the material flow during welding.

Abstract: In order to obtain the near net shaped SiC/SiC composite pins without the processing cost, four kinds of SiC fiber pin preforms including the knitting yarn and core yarn with two dimension braided structure were designed. The SiC/SiC composite pins were fabricated by precursor infiltration pyrolysis (PIP) process used a liquid SiC ceramic precursor. The results showed that, the near net shaped SiC/SiC composite pins could be obtained by using the designed SiC fiber preform and the graphite mould with curved groove. The macrostructure and microstructure of the SiC/SiC composite pins were observed by scanning electron microscope. Both the single shear stress-displacement curves and the double shear stress-displacement curves of the different kinds of SiC/SiC composite pins showed the saddle-shaped, which indicated the fracture model of the SiC/SiC composites pins was non-catastrophic, and the SiC/SiC composite pins in this paper possessed the secondary bearing capacity. This paper may provide some new ideas for fiber reinforced SiC ceramic matrix composites components designers.

Abstract: A new rectifier, called SPND or SNPD (Schottky-PN or -NP junction diode) and inherently showing low on-resistance and unipolar operation, was experimentally demonstrated for the first time on 4H-SiC. It is structured with an n^– or a p^– region of very low doping that is sandwiched and completely depleted between a Schottky junction and a one-sided PN junction. Either electrons or holes, but not both, contribute to the current conduction process. Clear and sharp rectifying properties are observed over the entire range of applied voltage.

Abstract: The experimental results are presented for the research on stress in the connecting elements of the rods at a rotational-impact loading. The oscillograms are made demonstrating the power pulses and tangential stresses in the threaded joint.

Abstract: Pin structure GaN-based alpha particle detector with epitaxial growth on c-plane sapphire substrate through metal organic chemical vapor deposition (MOCVD) method, uses electron beam evaporation and photoetching machine to produce the ohmic contact electrodes of device. The electrical properties of device which were tested by I-V and C-V show that the device’s reverse leakage current is 9.9μA at 100V reverse bias voltage is at; and the detector’s junction capacitance is 19pF at 20V reverse bias voltage.

Abstract: Two families of Al⁺ implanted vertical p⁺in diodes that have been processed all by identical steps except the post implantation annealing one have been characterized with current voltage measurements from -100 to +5V at different temperatures. Analysis of the static forward current voltage characteristics shows two different ideality factor regions, which are distinct for each family. The reverse current voltage characteristics reveals corresponding two different activation energies. These are assumed to be correlated to the Z_1/2 defect for the one case and another one with an activation energy of 0.25eV.

Abstract: One of the eligibility brakes requirements that used by railway is the fulfillment of the prescribed limit of friction coefficien. Test performed to determination railway brake block friction coefficient using pin on disc test. This test convert brake force into normal force on load cell that could be replace by balance. But due to the existing gap between arm force and brake force, error could be happened. To minimalized this error, that gap had to be reduced. In this research, the gap was reduced from 4.5 cm to 1 cm. Data recording was modified from manual recording into automatic recording using LabView program. This modified was very usefull because recording data could be done easily.

Abstract: Innovation of the technological processes is a very important part of continuous improvement of each manufacturing company. Every manufacturing company is trying to optimize the production processes to achieve the improvement of basic indicators, which include price, quality and speed of the production process. One of the means to achieve these indicators is to optimize the cutting parameters, which ensure the desired quality of the surface in a shorter manufacturing time. Innovation of the technological parameters of the manufacturing company means to repair, improve, and transform these parameters, which are used and show loss limitations. Application of updated parameters for manufacturing company may refer to significant reduction of engineering times, improving the material flow and the other factors, but it is mainly costs saving. This article is specialized on the study of the surface quality of the material AISI 304 by turning technology with selected cutting tool of sintered carbide. This material is usable for actuator (actuators and reduction gears) too.