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.
Forging of metal powder preforms
Abstract Metal powder technology is currently arousing interest in many parts of the world as an economic method of producing components from metal powders. Considering the process of the forging of metal powder preforms under axisymmetric and plane strain conditions, the problems of pressure distribution at the die-work piece interface and die load have been analysed. The correctness of the yield criterion and interfacial friction law used during the analysis have also been verified experimentally. The results so obtained are discussed critically to illustrate the interaction of various parameters involved and are presented graphically.
Study on Electrical Explosion Mechanism and Ignition Characteristics of Copper and Aluminum Powder Under Ignition Solid Propellant
In order to study the characteristic of the electrical explosion of copper and aluminum powders, a multilayer generator was designed, an experimental system was set up, and the parameters of metal powder electrical explosion were measured and analyzed. The results show that the duration of the electrical explosion process increases significantly due to the addition of metal powder. The duration of aluminum powder electrical explosion jet flow is ~86.36 ms due to its self-sustained combustion, which releases a large amount of energy, and a small fraction of aluminum powder particles is not burned. The duration of copper powder electrical explosion jet flow is ~15.84 ms, and most of the copper powder particles are in the solid state. The current pause process is absent; instead, the first discharge process is connected to the second discharge process. The effect of copper powder on the first discharge process is greater than that of aluminum powder. Furthermore, the ignition ability of copper powder electrical explosion to solid propellant is stronger than that of aluminum powder in a closed bomb experiment. These results are indubitably meaningful for the application of metal powder electrical explosion and ignition of solid propellant in an electrothermal chemical gun.