2. WHAT IS ABRASIVE JET MACHINING ?
It is the material removal process where the
material is removed by high velocity stream of
air/gas or water and abrasive mixture .
An abrasive is small, hard particle having sharp
edges and an irregular shape .
High velocity jet is aimed at a surface under
controller condition .
3. COMPONENTS OF ABRASIVE JET
MACHINING
Abrasivedelivery system
Control system
Pump
Nozzle
Mixing tube
Motion system
4. 1. ABRASIVE DELIVERY SYSTEM
Auto abrasive delivery system has the capability
of storing abrasive & delivery the abrasive to
the bucket . It’s works auto programming
system by help of once measuring record & no
adjustment or fine tuning system . High sensitive
sensor gives extremely reliable & repeatable .
5. 2.CONTROL SYSTEM
The control algorithm that computes exactly
how the feed rate should vary for a given
geometry in a given material to make a precise
part .
The algorithm actually
determines desired variation
in the feed rate & the tool
path to provide an extremely
smooth feed rate .
6. 3.PUMP
Crankshaft & intensifier pump are mainly use
in the abrasive jet machine .
The intensifier pump was the
only pump capable of reliably
creating pressures high .
Crankshaft pumps are more
efficient than intensifier pumps
because they do not require a power robbing
hydraulic system ultra high pressure & more
stroke per minute .
7. 4.NOZZLE
All abrasive jet systems use the same basic two
stage nozzle . First , water passes through a
small diameter jewel orifice to form a narrow
jet .
The abrasive particles are accelerated by the
moving stream of water & they pass into a
long hollow cylindrical
ceramic mixing tube.
Generally two type of nozzle
use , right angle head &
straight head .
9. 5. MIXING TUBE
The mixing tube is where the abrasive mixes
with the high pressure water .
The mixing tube should be
replaced when tolerances
drop below acceptable levels .
For maximum accuracy ,
replace the mixing tube
more frequently .
10. 6.MOTION SYSTEM
In order to make precision parts , an abrasive
jet system must have a precision x-y table and
motion control system .
Tables fall into three general categories .
Floor-mounted gantry systems
Integrated table/gantry systems
Floor-mounted cantilever systems
11. WORKING PROCESS
High pressure water starts at the pump , and is
delivered through special high pressure
plumbing to the nozzle .
At the nozzle , abrasive is introduced & as the
abrasive/water mixture exits , cutting is
performed .
Once the jet has exited the nozzle , the energy
is dissipated into the catch tank , which is
usually full of water & debris from previous
cut .
13. AJM FEATURES
There are main features of AJM
Obtainable tolerances
Material to machine
Material thickness
Accuracy of table
Stability of table
Control abrasive jet
14. MACHINE ASPECTS
Around curves
Inside corner
Feed rate
Acceleration
Nozzle focus
Speed cutting
Pump pressure
Hardness & thickness
Software controlling the motion
Power at the nozzle
15. TYPES OF ABRASIVE MATERIALS
Different types of abrasive are used in abrasive
jet machining like garnet , aluminum oxide
, olivine , silica sand , silicon carbide ,etc .
Virtually any material can be cut by using
abrasive jet machining method , i.e harder
materials like titanium to steel.
Abrasive particles must be hard ,high toughness,
irregular in shape & edges should be sharp .
16. ADVANTAGES
Extremely fast setup & programming
No start hole required
There is only one tool
Low capital cost
Less vibration
No heat generated in work piece
Environmentally friendly
17. DISADVANTAGES
Low metal removal rate
Due to stay cutting accuracy is affected
Abrasive powder cannot be reused
Tapper is also a problem
18. CONCLUSION
The better performance , and the applications
represented above statements confirm that
ABRASIVE JET MACHINING is continue to
expand .
The new software’s used to minimize time and
investments , there by making it possible for
more manufacturers of precision parts to
install AJM centers .
