Electron Beam Machining (EBM)
19.1
Process Principles
19.2
Equipment
19.2.1 Electron Beam Gun
19.2.2 Power Supply
19.2.3 The Electron Beam Machining Systems
19.3
Process Parameters
19.4
Process Capabilities
19.5
Application Examples
19.6
Process Summary
19.7
References
19.1 PROCESS PRINCIPLES
Electron beam machining (EBM) is a thermal material removal process that utilizes a focused beam of high-velocity electrons to perform high-speed drilling and cutting. Just as in electron beam welding (Chap. 18),
material-heating action is achieved when high-velocity electrons strike the work piece. Upon impact, the kinetic energy of the electrons is converted into the heat necessary for the
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18). An electron "cloud" is generated by a superheated tungsten filament, which also acts as the cathode. A combination of repewng forces from the negative cathode and the attracting forces from the positive anode causes the free electrons to be accelerated and directed toward the work piece. Before passing through the anode, the beam travels through a bias electrode, which controls the flow of electrons and acts as a switch for generating pulses.
After passing through the anode, the electron beam is diverging rapidly and traveling at approximately one-half the speed of light. A magnetic coil, which functions as a magnetic lens, repels and shapes the electron beam into a converging beam. The beam is then passed through a variable aperture which results in the removal of stray electrons from the beam's fringe areas, thus reducing the fmal focused spot diameter and producing a more favorable beam energy distribution for machining applications.
Beneath the aperture are three final magnetic coils that are used as the final magnetic lens, deflection coil, and stigmator. Pinpoint focusing is accomplished with the lens, and a small amount of controllable beam
deflection is achieved with the deflection coil. The stigmator corrects minor beam aberrations and ensures a round beam at the work piece.
To protect the electron beam gun from metal spatter and vapor, a series of rotating slotted disks are often mounted
Raytheon defines this as, “Electronic warfare uses focused energy, usually radio waves or laser light, to confuse or disable an enemy's electronics. It can also involve listening —collecting an enemy's radio signals or sensing the radar of an incoming missile.” Raytheon also has a wide range of utilities that use electron warfare. They have Jammers that confuse adversaries, integrated suites that counteract missiles and radars, airborne decoys to distract enemies, and much more. Raython is planning on developing tactical laser and improved jammers in the nearby future. (Raytheon Electronic
- I think that the electrons that are emitted from the cathode are emitted with a range of velocities (perhaps like a Boltzmann distribution where average speed clusters in the middle of the range).
This paper provides information on the Quinn model which is also known as the competing values framework. It provides background information about the framework, and how through collaborative usage of it leads to successful management outcomes. Analysis of the effectiveness of the framework is demonstrated through examples from a case called the Nuclear Tube Assembly Room. This paper will also provide insight to the effects and the importance of using the framework to optimize organizational effectiveness and managerial leadership.
Eddy Currents: circular movements of electrons due to a changing flux passing through the metal
If W = 0 then there is no change in the kinetic energy of the electrons, thus their speed remains constant; the acceleration provided by the magnetic field was used only to change the direction.
from atoms, generating a flow of electricity.” Knowing this new information, it is possible that
The creation of the Tueller Drill by Dennis Tueller has saved many lives and continues to do so. Tuellers teachings have led to some of the foremost tactics within the police force and military communities. The Tueller Drill is used to teach members of armed forces how to deal with threats as they maneuver the close quarters battlefield abroad. It also teaches police officers how to decide if lethal force is justified and how to prevent situations from escalating from a peaceful altercation to a deadly fight. The Tueller Drill is taught to upcoming police officers and can be more effectively taught to prevent both officer and subject injury.
The "2nd U.S. Circuit Court of Appeals" held that those business practices that have had a disparate impact effect on the older workers are now considered to be actionable under one national anti-discrimination law (Hamblett, 2004). The case does reaffirm a second Circuit precedent that had been set but which is at odds with what a majority of federal courts have held. The appeals court supported the idea that a layoff plan had been properly brought under the The Age Discrimination in Employment Act of 1967 (ADEA) although the company did not have the intention of discriminating.
For the problem on distribution partner, Augat has the option to stick with White Radio, or to seek new partnerships in distribution like Anixter Canada, or Deskin Sales. Though this would help Augat enhance the coverage in terms of suppliers (or end-users) and a potential increase in market presence. However, on the other hand, Augat would lose the exclusive relationship it was with White Radio, knowing White Radio’s Steve Quinn’ knowledge about Cable TV MSO’s approval process. In addition, the other distribution companies also carry competitor’s products and there is no guarantee that they would push
The Coolidge tube could operate to energies up to 100,000 volts. General Electric went on to make x-ray tubes capable of operating at energies up to 1,000,000 volts, which gave the x-ray technology enough stability to become industrialized and mass produced.
Ruska’s working model was a transmission electron microscope (TEM). It sends a beam of electrons, rather than light, through the object being viewed. The object to be viewed must be very thin so the electrons can pass through it. Because air is too dense for electrons to pass through, the object must be placed in a vacuum chamber. A beam of electrons is then focused on the object. Magnetic lenses that act in the same way as glass lenses in an optical microscope spread the part of the beam that passes through the object.
A particle accelerator is a machine that is capable of accelerating particles to very high speeds. The types of particles that are accelerated are protons, electrons and atomic nuclei. Particle accelerates have a Particle Source which is where the particle is before it launched. It also has a Beam Pipe which is where the particles travel around the machine. There are also electric fields, electromagnets, detectors and targets. (Dotson, 2015) The electric fields are spaced out and create radio waves which accelerate particles. The electromagnets help steer and focus the beam of particles when they travel through the beam tube. (Dotson, 2015) The detectors and targets help record data of the particles speed and behavior at high speeds.
However, much of the phenomenon observed during the photoelectric effect was in contradiction to the Wave Theory of Light. For instance, the energy contained in electromagnetic waves, and the amount of energy that would strike a sodium electron can be calculated. Such a calculation shows that an electron could indeed gain enough energy to be liberated from the sodium, but only after the sodium had been
GMAW (Gas Metal Arc Welding) is more economic; Springer reports that “ GMAW is an economic process because it has higher speeds and higher deposition rates than manual arc welding. There is also no need to constantly change electrodes” ( Page 11). GMAW has a higher speed, which means that you can get the job done faster. It also has high deposition rates which makes the weld look clean and smooth.” This method can be used for a high range of work, but it is not suited for repair work because of it’s weld quality” (Page 4). This process can be used for many variations of work including root welds, joints, T’s, butts, laps, and many more applications. Even though its used for many practices, it is not recommended to use this method for
CNC machining it works particularly well for hard, relatively brittle materials like steels and other metal alloys to produce high accuracy parts with well-defined properties and normally be more homogeneous and predictable in quality.