A PAPER ON :

CONTENTS:

ABSTRACT

GENERAL THEORY

INTRODUCTION

MATERIALS USED AS AN ABRASIVE

ADVANTAGES TO ABRASIVE JETS MACHINING

CONCLUSION

APPLICATION

ABSTRACT

Above: Cutting under water to reduce Noise and splash

Cutting tests were conducted on such materials as aluminum, glass, titanium andGraphite composites

Abrasive-water jet cutting is among the most efficient methods of energy utilization for high precession material cutting, removing and plaining.

INTRODUCTION:

A machining operation is basically a material removal process, where material is removed in the form of chips.

A machining operation is basically a material removal process,

where material is removed in the form of chips.

Abrasive-water jets are formed in a small abrasive-jet nozzle.

GENERAL THEORY:

Water is pressurized up to 400 MPa

Typical particle velocities are 300-600 m/s with mass flow rates of about 10 g/s.

Cutting or controlled depth penetration (milling) of the targetMaterial occurs as a result of complex erosion phenomena

Abrasive-water jet parameters,which include

• Hydraulic parameters

-Waterjet orifice diameter

- Supply pressure

• Abrasive parameters- Material (density, hardness, shape)- Size , feed method

- Flow rate,abrasive condition

• Mixing nozzle parameters

- Mixing chamber dimensions- Nozzle material

•Cutting parameters- Traverse rate,number of passes

- Standoff distance,angle of cutting

A machine shop without a waterjet, is like a carpenter without a hammer - Sure the carpenter can use the back of his crow bar to hammer in nails, but there is a better way..."

Both technologies use the principle of pressurizing water to extremely high pressures, and allowing the water to escape through a very small opening (typically called the "orifice" or "jewel").

(Above: Pure-water "Waterjet")

The inlet water is typically pressurized between 20,000 and 60,000 Pounds per Square Inch (PSI).  (Or 1300 - 4000 "bar" if you prefer metric). This is forced through a tiny hole in the jewel, which is typically 0.007" to 0.015" in diameter (0.18 - 0.4mm)  This creates a very high velocity beam of water!

A diagram of an abrasive jet. Notice that it is just like a water jet with more stuff

underneath the jewel. An actual photograph of the same nozzle, with the guard removed, cutting out some

parts.

THE MATERIAL USED AS AN ABRASIVE:

The materials commonly used in this area are: GARNET, SILICA SAND and GLASS BEADS

A different pattern of traverse on every pass will complicate the milling process.

a) Garnet b) Silica sand

c) Glass beads

Which nozzle is best for my material?

Water Jet Nozzle AbrasiveJet Nozzle

Soft rubber Hardened tool steel Plastic

Foam Titanium Nylon

Extremely thin stuff like Foil Aluminum Graphite

Carpet Hard Rubber Many ceramics

Paper and cardboard Stone Carbon Fiber

Soft Gasket material Inconel® Composites

Candy bars Hastalloy mild steel

Diapers Copper Stainless Steel

Soft, or thin wood Exotic materials Kevlar

...All sorts of other soft stuff Hard, or thick Wood Granite

Glass (even bullet proof!)  Mixed materials

Marble Brass

In Fact, there are very few materials that abrasivejets can't cut!

Extremely fast setup and programming

Very little fixturing for most parts

Machine virtually any 2D shape (and some 3D stuff)

Very low side forces during the machining

Almost No heat generated on your part

No start hole required

Machine thick stuff

Environmentally friendly

ADVANTAGES TO ABRASIVE JETS MACHINIG

APPLICATION

Printed Circuit Boards: Wire Stripping: Food Preparation:

Tool Steel: Wood Cutting: Cleaning Applications:

CONCLUSION:

And Finally I Conclude this by saying that, it’s definite that this technology has over ridden the present conventional cutting, milling, and polishing operation which are widely used in the manufacturing technology.

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