Fracturing and Deformation Characteristics of Aluminium Preform during Cold Forging at Low Strain Rates
The industrial processing of sintered powder preform has been developed for manufacturing various engineering components. The present investigation has been undertaken to analyze the deformation characteristics during the cold forging of sintered aluminium preform at low strain rates. Experiments have been conducted and measurements made on deformation during cold forging on aluminium preforms with lubricated end conditions. Experimentally obtained flow load and plastic work done are in good agreement with theoretical estimates.
Sustaining behavior of sintered forged aluminum powder specimens made by unconventional die
Abstract The forging of sintered metal-powder preforms is new manufacturing method in many parts of the world. The sintered forging is an economic method of manufacturing of parts from metal powder. In this paper authors used a modified die with several layers of different materials and heat treated accordingly instead of using tool steel to make an effective die with reduced cost. Quenching is also performing of selected parts to harden the die material. The samples of aluminum powder are made and examined for different parameters along with microstructure and it was observed that pores in the material will eliminate after sintering process.
Simulation study of high power microwave generation by virtual cathode oscillation in coaxial vircator
Summary form only given, as follows. We have numerically simulated the high power microwave generation by virtual cathode oscillation in a coaxial vircator with 3 dimensional PIC code Magic. It is noted that the coaxial vircator has the advantage of an enhancement of power efficiency and gaining of narrow bandwidth frequency. The study is focused on the design of a diode structure for a coaxial vircator suitable for Chundoong IREB pulser (Max. 600 kV, 85 kA, 60 ns). It consists of a center annular cathode, a cylindrical meshed-anode and a reflector. The simulation results showed that the coaxial vircator can indeed be operated at the selected frequency with the narrow bandwidth and the microwave output power strongly depends on the position and geometry of the reflector. From this simulation results we expect that the maximum microwave output power will be obtained by the reflector of 4 cm in width and also 4 cm in distance away from the IREB, where the resonant frequency of microwave from coaxial vircator is simulated to be 6.577 GHz.