Abrasive jet machining
- AJM uses a stream of fine grained abrasive (of size 10 to 40 microns) mixed with the air or some other carrier gas at high pressure.
- This stream is directed on the work surface by using a suitable nozzle.
- The velocity of carrier gas or air is upto 200 to 400 m/sec.
Working :-
- Through hopper, fine grained abrasive powder is filled in a mixing chamber.
- The gas or air is supplied under pressure into the chamber, pressure of gas varies from 2 to 8 kg/cm square.
- The gas is supplied through the pipeline which carries a pressure gauge and regulator to control the flow.
- This mixture of high pressure gas and compressed air is passed through a nozzle on the surface of workpiece, and due to high speed mixture erosion takes place and metal gets removed.
Advantages :-
- Brittle materials of thin sections can be easily machined.
- No direct contact between the tool and workpiece, hence less damage to the workpiece surface.
- Holes of any shape and intricate cavities can be machined.
- Power consumption is low.
Disadvantages :-
- Am is only suitable for brittle materials, as MRR is high for brittle materials.
- MRR is kowalska i.e. upto 0.05 cubic centimeter/hr.
- The used abrasive powder can not be reused.
Applications :-
- It is used for drilling holes, cutting slots, cleaning hard surfaces, deburring, polishing, etc.
- It is used for producing high quality surface.
- Used for aperture drilling of an electronic microscope