MMM LECTURE NOTES FINAL.pdf

Mixing chamber the gas along with the entrained

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mixing chamber, the gas, along with the entrained abrasive particles (10 40 μ m), passes through a 0.45-mm-diameter tungsten carbide nozzle at a speed of 150 to 300 m/s. Aluminum oxide (Al2O3) and siliconcarbide powders are used for heavy cleaning, cutting, and deburring.Magnesium carbonate is recommended for use in light cleaning and etching, while sodium bicarbonate is used for fine cleaning and the cutting of soft materials. Commercial-grade powders are not suitable because their sizes are not well classified. They may contain silica dust,which can be a health hazard. It is not practical to reuse the abrasive powder because contaminations and worn grit will cause a decline of themachining rate. The abrasive powder feed rate is controlled by the amplitude of vibrations in the mixing chamber. The nozzle standoff distance is 0.81 mm. The relative motion between the workpiece and the nozzle is manually or automatically controlled using cam drives, pantographs,tracer mechanisms, or using computer control according to the cut geometry
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Modern Manufacturing Methods required. Masks of copper, glass, or rubber may be used to concentrate the jet stream of abrasive particles to a confined location on theworkpiece. Intricate and precise shapes can be produced by using masks with corresponding contours. nozzle at a speed of 150 to 300 m/s. Aluminum oxide (Al2O3) and silicon carbide powders are used for heavy cleaning, cutting, and deburring.Magnesium carbonate is recommended for use in light cleaning and etching, while sodium bicarbonate is used for fine cleaning and the cutting of soft materials. Commercial-grade powders are not suitable because their sizes are not well classified. They may contain silica dust,which can be a health hazard. It is not practical to reuse the abrasive powder because contaminations and worn grit will cause a decline of the machining rate. The abrasive powder feed rate is controlled by the amplitude of vibrations in the mixing chamber. The nozzle standoff distance is 0.81 mm. The relative motion between the workpiece and the nozzle is manually or automatically controlled using cam drives, pantographs,tracer mechanisms, or using computer control according to the cut geometry required. Masks of copper, glass, or rubber may be used to concentrate the jet stream of abrasive particles to a confined location on the workpiece. Intricate and precise shapes can be produced by using masks with corresponding contours. Dust removal equipment is incorporated to protect the environment.
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Modern Manufacturing Methods Applications 1. Drilling holes, cutting slots, cleaning hard surfaces, deburring, polishing,and radiusing 2. Deburring of cross holes, slots, and threads in small precision parts that require a burr-free finish, such as hydraulic valves, aircraft fuel systems, and medical appliances 3. Machining intricate shapes or holes in sensitive, brittle, thin, or difficult-to-machine materials 4. Insulation stripping and wire cleaning without affecting the conductor 5. Micro-deburring of hypodermic needles 6.
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  • Fall '12
  • JeraldBrevick
  • EDM, conventional machining processes, Jet Machining

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