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Questions and Answers
What is the typical range of nozzle orifice diameters used in abrasive water jet cutting (AWJC)?
What is the typical range of nozzle orifice diameters used in abrasive water jet cutting (AWJC)?
What is the typical range of abrasive particle sizes used in abrasive water jet cutting (AWJC)?
What is the typical range of abrasive particle sizes used in abrasive water jet cutting (AWJC)?
What is the typical water pressure used in abrasive water jet cutting (AWJC)?
What is the typical water pressure used in abrasive water jet cutting (AWJC)?
What is the typical standoff distance used in abrasive water jet cutting (AWJC)?
What is the typical standoff distance used in abrasive water jet cutting (AWJC)?
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What is the typical abrasive feed rate used in abrasive water jet cutting (AWJC)?
What is the typical abrasive feed rate used in abrasive water jet cutting (AWJC)?
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What is the most common type of orifice jewel used in abrasive water jet cutting (AWJC)?
What is the most common type of orifice jewel used in abrasive water jet cutting (AWJC)?
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What is a disadvantage of Electrochemical Machining (ECM)?
What is a disadvantage of Electrochemical Machining (ECM)?
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Which application is NOT listed for Electrochemical Machining (ECM)?
Which application is NOT listed for Electrochemical Machining (ECM)?
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What is the main purpose of Electrochemical Deburring (ECD)?
What is the main purpose of Electrochemical Deburring (ECD)?
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How does Electrochemical Deburring (ECD) differ from Electrochemical Grinding (ECG)?
How does Electrochemical Deburring (ECD) differ from Electrochemical Grinding (ECG)?
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What makes Electrochemical Grinding (ECG) different from conventional grinding methods?
What makes Electrochemical Grinding (ECG) different from conventional grinding methods?
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Why are cycle times much shorter in Electrochemical Deburring (ECD) compared to Electrochemical Grinding (ECG)?
Why are cycle times much shorter in Electrochemical Deburring (ECD) compared to Electrochemical Grinding (ECG)?
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What type of material is suitable for Electrochemical Machining (ECM)?
What type of material is suitable for Electrochemical Machining (ECM)?
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What is the purpose of the flowing electrolyte in Electrochemical Machining?
What is the purpose of the flowing electrolyte in Electrochemical Machining?
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Which materials are commonly used for electrodes in Electrochemical Machining?
Which materials are commonly used for electrodes in Electrochemical Machining?
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What voltage range is typically used in Electrochemical Machining?
What voltage range is typically used in Electrochemical Machining?
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Why is Electrochemical Machining preferred for parts that should not have any thermal damage?
Why is Electrochemical Machining preferred for parts that should not have any thermal damage?
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In Electrochemical Machining, what function does the tool serve in relation to the workpiece?
In Electrochemical Machining, what function does the tool serve in relation to the workpiece?
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Study Notes
Abrasive Water Jet Cutting (AWJC)
- Abrasive particles (aluminum oxide, silicon dioxide) are added to the water jet stream.
- Grit sizes range between 60 and 120 μm.
- Grits are added to the water stream at about 0.25 kg/min.
- The orifice jewel may be ruby, sapphire, or diamond, with sapphire being the most common.
- Nozzle orifice diameter: 0.25 - 0.63 mm, which is slightly larger than in water jet cutting.
- Water pressures are about the same as in WJC (400 Mpa).
- Typical standoff distances are between 1/4 and 1/2 of those in WJC.
Abrasive Jet Machining (AJM)
- A material removal process caused by the action of a high-velocity stream of gas containing small abrasive particles.
- Pressure: 0.2 to 1.4 Mpa.
- Nozzle orifice diameter: 0.075 to 1.0mm.
- Velocities: 2.5 to 5.0 m/s.
- Gases: dry air, nitrogen, carbon dioxide, and helium.
- Typical abrasives: aluminum oxide (for aluminum and brass), silicon carbide (for stainless steel and ceramics), and glass beads (for polishing).
- Grit sizes are small, 15-40 μm in diameter and must be uniform in size for a given application.
Advantages of AJM
- Low cost.
- Less vibration.
- No heat is generated in the workpiece.
- Ability to cut complex holes.
- No burrs as in conventional machining.
- Low tool wear.
- Relatively high metal removal rates for hard and difficult metals.
- Capable of machining complex parts and hard materials.
- High production and high tolerances.
Electrochemical Deburring (ECD)
- Modification of ECM to remove burrs or round sharp corners on metal parts.
- The electrolyte flows through the hole to carry away the burr particles.
- Cycle times are much shorter, typically less than a minute.
Electrochemical Grinding (ECG)
- An improved electrochemical grinding wheel electrode consisting of electrically conductive abrasive grains bonded together with nonconductive bonding material.
Electrochemical Machining Processes
- Electrical energy is used in combination with chemical reactions to remove material.
- Reverse of electroplating in that it removes material instead of adding it.
- Work material must be a conductor.
Electrochemical Machining (ECM)
- Material removal from an electrically conductive workpiece using an electrode (tool) in close proximity to the work but separated by a rapidly flowing electrolyte.
- Material is removed from the anode workpiece (positive pole) and transported to the cathode tool (negative pole) in an electrolyte bath.
- Electrolyte carries off the material that has been removed from the workpiece.
- Electrolyte – salt solutions like sodium chloride (NaCl) or sodium nitrate (NaNO3) mixed in water.
- The flowing electrolyte also serves the function of removing heat and hydrogen bubbles created in the chemical reactions of the process.
- Electrode materials: Cu, brass, or stainless steel.
- Tool has the inverse shape of the part.
- Tool size and shape must allow for the gap.
- Die is gradually lowered into workpiece.
- Low voltage (5-25 V) and very high current (700 amps).
Advantages of ECM
- Does not cause any thermal damage to the parts.
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Description
Learn about Abrasive Water Jet Cutting (AWJC) where abrasive particles are added to a water jet stream. Discover the types of abrasives used, grit sizes, orifice jewel materials, and nozzle orifice diameters.
