1. ABRASIVE JET MACHINING Prepared by B.BALAMURALI AP/MECH
SNS COLLEGE OF ENGINEERING, COIMBATORE   DEPARTMENT OF MECHANICAL ENGINEERING  
ABRASIVE JET MACHINING Prepared by B.BALAMURALI AP/MECH
ME UMP / TOPIC-7
SNSCEME PRESENTATION

2. Factors considered for selection of process.
RECAP
Factors considered for selection of process.
ME UMP / TOPIC-7
SNSCEME PRESENTATION

3. ABRASIVE JET MACHINING
The mechanism of material removal is erosion or chipping action.
The jet of inert gas and abrasive particles strike the work piece at high velocity ( m/s).
This can be employed for cutting, cleaning, etching, polishing, deburring and trimming.
ME UMP / TOPIC-7

4. WORKING OF AJM
ME UMP / TOPIC-7

5. WORKING OF AJM
Gases like dry air, N2,CO2,helium are compressed to the pressure range of 0.2 to 1.4 Mpa before entering into the mixing chamber.
Abrasive particles are sent to the mixing chamber.
The proper mixing of gas with abrasives are ensured by inducing vibration to the mixing chamber through the vibrator.
The gas abrasive mixture propels through the to nozzle orifice of diameter to 1.0 mm at velocities of m/s.
ME UMP / TOPIC-7

6. WORKING OF AJM
Distance of the range 0.25 – 0.75mm is maintained between the nozzle tip and work surface which is named as standoff distance (or) Nozzle tip distance.
The jet of gas-abrasive particles which is coming out from the nozzle strikes the work surface at high velocity ,erodes the material from the work piece.
The process is usually performed manually by an operator who directs the nozzle at the work surface.
ME UMP / TOPIC-7

7. ACTIVITY!!!
DUBBING……………..
ME UMP / TOPIC-7

8. Hopper or Abrasive feeder Nozzle Abrasives Mixing Chamber
ELEMENTS OF AJM
Gas propulsion system
Hopper or Abrasive feeder
Nozzle
Abrasives
Mixing Chamber
Machining Chamber
ME UMP / TOPIC-7

9. ELEMENTS OF AJM Gas propulsion system - Dry air,N2,CO2,helium
Hopper or Abrasive feeder
- Control the quantity of abrasive particles
Nozzle
- Circular or rectangular cross section
- Tungsten carbide(WC) -12 to 20 hours /Synthetic sapphire- Aluminium oxide (Al2O3) – 300 hours
ME UMP / TOPIC-7

10. ELEMENTS OF AJM Abrasives - Hard & Brittle materials
- Al2O3, Silicon carbide (SiC), Dolomite, glass beads, Crushed glass, Sodium bi carbonate.
Type of Abrasive
Recommended size
Purpose
Aluminium Oxide
10,25,50 microns
Cleaning, cutting, Deburring
Silicon carbide
25 microns
Faster cutting of hard material
Dolomite
200 microns
Cleaning & etching
Glass beads
0.3 – 0.6 mm diameter
Polishing & Deburring
Sodium bi carbonate
Cleaning, cutting, Deburring of soft materials
ME UMP / TOPIC-7

11. ELEMENTS OF AJM Mixing Chamber
- Vibrator is provided at the bottom of the mixing chamber to ensure proper mixing of abrasive particles with air.
Machining Chamber
- Stand off distance is 0.8mm (approx.)
- If toxic material (beryllium) is machined ,special attention is given to dust collection system.
ME UMP / TOPIC-7

12. NAME THE PARTS OF AJM
ME UMP / TOPIC-7

13. ME UMP / TOPIC-7