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    Machining Lab

    Uploaded by

    Arunachalam Narayanan
    The document discusses abrasive jet machining, which uses a high-pressure stream of gas and abrasive particles to cut hard and brittle materials. It consists of abrasive jet machining, water jet machining, and abrasive water jet machining. The document provides details on the abrasive jet machining process, including setup, mechanisms, process parameters, effects of parameters, applications, advantages, and disadvantages.

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    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd

    Machining Lab

    Uploaded by

    Arunachalam Narayanan
    53 views6 pages
    The document discusses abrasive jet machining, which uses a high-pressure stream of gas and abrasive particles to cut hard and brittle materials. It consists of abrasive jet machining, water jet machining, and abrasive water jet machining. The document provides details on the abrasive jet machining process, including setup, mechanisms, process parameters, effects of parameters, applications, advantages, and disadvantages.

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    © Attribution Non-Commercial (BY-NC)

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    The document discusses abrasive jet machining, which uses a high-pressure stream of gas and abrasive particles to cut hard and brittle materials. It consists of abrasive jet machining, water jet machining, and abrasive water jet machining. The document provides details on the abrasive jet machining process, including setup, mechanisms, process parameters, effects of parameters, applications, advantages, and disadvantages.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    53 views6 pages

    Machining Lab

    Uploaded by

    Arunachalam Narayanan
    The document discusses abrasive jet machining, which uses a high-pressure stream of gas and abrasive particles to cut hard and brittle materials. It consists of abrasive jet machining, water jet machining, and abrasive water jet machining. The document provides details on the abrasive jet machining process, including setup, mechanisms, process parameters, effects of parameters, applications, advantages, and disadvantages.

    Copyright:

    Attribution Non-Commercial (BY-NC)
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
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    Jet machining

    Jet machining
    Consisting of:
    Abrasive Jet Machining Water Jet Machining Abrasive water jet machining

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Abrasive Jet Machining


    High pressure air with fine powder, blended together to form an abrasive mixture This mixture is sent through a small, precisely machined nozzle The result is a highly accurate abrasive stream used for cleaning, cutting, drilling, deburring

    Abrasive Jet Machining-Set up Machining-

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Abrasive Jet Machining-Set up Machining(Schematic)

    Abrasive jet machining (AJM)


    A high velocity stream of gas containing small abrasive particles Pressure: 0.5 2 Mpa Nozzle orifice diameter: 0.08 1 mm Velocities: 150 - 300 m/s Gases: dry air, nitrogen, carbon dioxide and helium The process is usually carried out manually by an operator AJM is normally used as a finishing process Applications: deburring, trimming and deflashing, cleaning and polishing Applied on hard, brittle materials (glass, silicon, mica and ceramics) that are in the form of thin flat stock Typical abrasives: aluminum oxide (for aluminum and brass), silicon carbide (for stainless steel and ceramics), and glass beads (for polishing)

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Abrasive Jet Machining

    Machining system
    Relative motion between nozzle and work piece can be manual Or automatically controlled using cam drives, tracer mechanisms or using computer controlled according to the cut geometry required Masks of copper, glass or rubber can be used to concentrate the jet stream of abrasives to a confined area on the work piece Intricate and precise shapes can be produced using masks with corresponding contours. Dust removal or collecting equipment must be incorporated to protect the environment
    Prepared by Dr .K..Elangovan

    Abrasive Machines are extremely versatile and have limitless applications. They have the power to cut and drill materials as hard as diamonds as well as the precision of delicate items like fabric and paper Grit sizes are small, 15-40m in diameter and must be very uniform in size for a given application No recycling of abrasives; abrasive grains are fractured, worn and contaminated

    Prepared by Dr .K..Elangovan

    Mechanism
    The abrasive particles from the nozzle follow parallel paths for a short distance Then the abrasive jet flares outward like a narrow cone When the sharp-edged abrasive particles of Al2O3 or SiC hit a brittle and fragile material at high speed, tiny brittle fractures are created from which small particles dislodge The dislodged particles are carried away by the air or gas
    Prepared by Dr .K..Elangovan

    Process Parameters
    Carrier Gas (Non toxic, Cheap - Air, Carbondi-oxide, Nitrogen) Type of abrasive( Aluminium oxide, Silicon carbide, sodium bicarbonate, Dolomite) Size of abrasive grain (coarse grains-cutting Fine grains- polishing and de burring) Work material (Glass, ceramics, refractories) Nozzle design( Circular, Rectangular- Mat: Wc, Sapphire) Shape of cut (Not suitable to sharp corners) Velocity of abrasive jet Stand off distance

    Prepared by Dr .K..Elangovan

    Velocity of abrasive jet

    Effect of process parameters

    Abrasive:Al2O3 Work Material: Cemented Carbide


    Prepared by Dr .K..Elangovan

    Abrasive:Al2O3 Work Material: Glass


    Prepared by Dr .K..Elangovan

    Stand off distance-Accuracy

    Stand off distance-MRR

    SOD, mm
    Prepared by Dr .K..Elangovan Prepared by Dr .K..Elangovan

    Advantages
    No heat generation-Cool Process (Heat-sensitive materials like glass, quartz, sapphire, and ceramics can be machined) No surface damage Low capital investment& Power consumption Ability to cut thin brittle materials (super alloys and refractory materials)

    Applications
    Drilling holes, cutting slots, cleaning hard surfaces De burring 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 Removal of flash and parting lines in moulding parts Deburring and polishing plastic, nylon components Cutting thin sectioned fragile components Cleaning mould cavities Frosting glass plates and tubes Marking on glass cylinders

    Disadvantages
    Not suitable for ductile materials The abrasive may get impeded in the work surface Additional cleaning is required Stray cuts &Poor accuracy( 0.1 mm) High nozzle wear rate Environment hazard

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Cleaning of corroded surface

    Frosted Glass

    Before cleaning

    After cleaning

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Casting cleaned by Abrasive Jet

    Abrasive Jet Cleaning Equipment

    Prepared by Dr .K..Elangovan

    Prepared by Dr .K..Elangovan

    Before cleaning

    After cleaning
    Prepared by Dr .K..Elangovan

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