This document provides an overview of water jet machining (WJM) and abrasive water jet machining (AWJM). It discusses the working principles, history, types of systems and components. Key points covered include: WJM uses high-pressure water only while AWJM mixes abrasives with water to cut harder materials; applications include cutting various soft materials for WJM and metals, glass for AWJM; factors like pressure, abrasives, stand-off distance affect performance; and limitations include high costs and inability to cut very hard materials like diamonds.

1. WATER JET
MACHINING
Presented by
Hassan Ahmed Abdullrazeq
Guided by
Prof. Sameh Habib

2. CONTENT
- Introduction
- Working principle
- History of water jets
- WJM timeline
- Machining system
- Cutting head
-WP holding devices
- Abrasives in AWJM

3. - Process parameters
- Factors affecting WJM performance
- Motion system
- Cutting geometry
- Applications
- Ice Jet Machining
- WJM vs. Other modern processes
- Limitations
- Advantages

4. INTRODUCTION
Water Jets is a mechanical energy based
non-traditional and non-
conventional machining process used to
cut and machine soft and non-
metallic materials. It involves the use of
high velocity water jet to smoothly cut a
soft workpiece.

5. THERE ARE TWO TYPES OF
WATER JETS:
Water jet
machining(WJM)
Abrasive water jet
machining(AWJM)

6. WHAT IS THE DIFFERENCE
BETWEEN (AWJM) AND (WJM)?
Abrasive Water Jet Machining(AWJM) uses a mixture
of water and an abrasive substance to cut hard
materials such as metal or granite. While Water
Jet Machining(WJM) uses only pure water. And its
used for softer materials such as food and rubber.

7. Material removal processes are divided into two groups
Conventional machining
•(Traditional)
Non-conventional machining
•(Non-Traditional)

8. Conventional machining: material removed in the
form of chips, by applying forces on the work material with a wedge
shaped cutting tool that is harder than the work material
Non-Conventional machining: There is no direct
contact between the tool and the work piece.

9. When using non-conventional machining
?
•Extremely hard and brittle materials are difficult to machine by
traditional machining processes.
•When the work piece is too flexible or slender to support the cutting
or grinding forces.
• When the shape of the part is too complex.

10. • In Water Jets we get thin jets of high pressure(200-400 MPa ) using
intensifier pump, This ultra-high pressure water is forced through
a tiny (0.15-0.4mm) orifice jewel
• When high-pressure water jet emerges from a nozzle, it attains a
large kinetic energy
• High-velocity jet (900-1000 m/s) strikes the workpiece, its kinetic
energy is converted into pressure energy including high stresses in
the work material.
Working
Principle

11. Using water as a cutting method for soft materials has been around for
decades, but early forms such as the paper metering system by the
Paper Patents Company in the 1930s used relatively low-pressure
water. High pressure waterjet technology truly took form in the post-war
era, resulting in faster cutting and greater precision. Reliability
remained a challenge, though, until the early 1970s when Dr. John
Olsen developed the first reliable ultra-high pressure pump.
History of
waterjets

12. The first publications on the modern Abrasive Waterjets (AWJ) cutting
were published by Dr. Mohamed Hashish in the 1982 BHR proceedings
showing, for the first time, that waterjets with relatively small amounts of
abrasives are capable of cutting hard materials such as steel and
concrete. The March 1984 issue of the Mechanical Engineering magazine
showed more details and materials cut with AWJ such as titanium,
aluminum, glass, and stone. Dr. Mohamed Hashish, was awarded a patent
on forming AWJ in 1987. Dr. Hashish, who also coined the new
term Abrasive Waterjet (AWJ), and his team continued to develop and
improve the AWJ technology and its hardware for many applications which
is now in over 50 industries worldwide.

13. -1930s
Low-pressure waterjet system used to cut paper.
Abrasive waterjet nozzle concept patented.
-1940s
High pressure seals developed for aviation & automotive hydraulics
-1950s
Ultra-high pressure (100,000 psi, 6,900 bar) liquid jet used to cut aerospace
metals
Numerical Control (NC) system developed by John Parsons High pressure
waterjet developed to cut plastic shapes
WJM timeline

14. -1960s
Up to 50,000 psi (3,450 bar) pulsing waterjet created at Union Carbide and
cut metal and stone, High Pressure pumps manufactured for polyethylene
industry
-1970s
Bendix Corporation develops concept of using corundum crystal for waterjet orifice
Dr. John Olsen develops and patents the high pressure fluid intensifier First
mainstream commercial waterjet cutting system introduced
-1980s
Boride Corp. develops ROCTEC ceramic tungsten carbide composite mixing tubes
Evolution of 1930s abrasives nozzle design brings abrasivejet machining to reality

15. MACHINING SYSTEM
-Reservoir: It is used for storing
water that is to be used in the
machining operation.
-Pump: It pumps the water from the
reservoir.
-Intensifier: It is connected to the pump.
It pressurizes the water acquired from
the pump to a desired level.

16. -Accumulator: It is used for temporarily storing the pressurized
water. It is connected to the flow regulator through a control valve.
-Control Valve: It controls the direction and pressure of pressurized
water that is to be supplied to the nozzle.
-Flow regulator: It is used to regulate the flow of water.
-Nozzle: It renders the pressurized water as a water jet at high
velocity.

17. CUTTING HEAD
-WJM cutting head
- AWJM cutting head
There are two types of cutting
heads in water jets:

18. WJM cutting head
Water is fed through specially designed pressure-proof
flexible pipelines to the cutting head. The cutting head
consists of a pneumatically operated valve and a nozzle
tube with a precious stone orifice (normally made in
sapphire or diamond) at its outlet. The cutting jet exits
the orifice at up to three times the speed of sound.

19. AWJM cutting head
A special abrasive head is mounted on the water nozzle. In this head,
the abrasive is mixed with the pressurized water. The movement of
the cutting head is normally CNC controlled through the waterjet
cutting unit

20. W.P holding devices
The most used W.P holding device in WJM is the hopper
in the work material. For securing the work piece in its place L shaped
angle plates was used with holes drilled on them
long their length. The work piece also has the holes drilled in it so that
both the plate and the
work piece can be bolted together making it fixed. The L-plates were
bolted to the mild steel
box. The main advantages in this type of work holding system is that it
can handle various sizes
of work pieces by attaching various plates.

22. Abrasives in AWJM
-Abrasives should be harder than the workpiece material.
-The size of Abrasives starts from 10 μm to 150 μm
-Garnet, silica sand ,silicon carbide, alumina, glass beads, and steel
grit are the most commonly used abrasives.
-The percentage of the Abrasives in the mixture of water-abrasive is
30%

23. Process parameters
• Orifice – Sapphires – 0.1 to 0.3 mm
• Focusing Tube – WC – 0.8 to 2.4 mm
• Pressure – 1500 to 4000 bar
• Abrasive – garnet and olivine - #125 to #60
• Abrasive flow - 0.1 to 1.0 Kg/min
• Stand off distance – 1 to 2 mm
• Machine Impact Angle – 60o to 900
• Traverse Speed – 100 mm/min to 5 m/min
• Depth of Cut – 1 mm to 250 mm

24. Factors affecting WJM
performance
Material Removal
Rate
Surface quality JET CUTTING RATE Workpiece type
Workpiece thickness Workpiece Feed rate JET NOZZLE Diameter JET FLUID type
JET FLUID velocity JET FLUID flowrate JET FLUID pressure JET FLUID viscosity

25. 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
Motion system

26. Cutting
geometry
The cut generated by an AWJM is called a
kerf.
Top of the kerf (bt) is wider than the bottom
of the kerf (bb).
bt is equal to the diameter of AWJ or AWJM.
Diameter of AWJ is equal to the diameter of
the focussing tube or the insert if the stand-
off distance (SOD) is around 1 to 5 mm.
Taper angle of the kerf can be reduced by
increasing the cutting ability of the AWJ.

27. is primarily used for cutting soft materials such as
rubber, foam, gaskets, leather, textiles and food.
APLICATIONS
Applications of AWJM
Applications of WJM
For hard materials that cannot be cut with
water only ,so it is used in many industries
such as glass ,metals ,aerospace and military
field.

28. EXAMPES
Cutting of Food:
For decades waterjet has been used effectively for food cutting
applications as it eliminates problems caused by cross-
contamination while producing high quality cuts. Today, waterjet
is used to cut a wide variety of food products including fresh
vegetables and meat products. It has proved to be an ideal
method of portioning chicken, celery and fish.

29. CUTTING PAPER
Waterjets changed the way the paper and disposable diaper industry
does business. Thirty years ago, manufacturers faced the same
concerns many manufacturers have today: reliability, redundancy, 24-
hour operation. Waterjet slitting systems are the fastest, most efficient
way to cut paper and disposable diaper products. Waterjets produce no
airborne dust, and do not dull.

30. Cutting of Glass:
Abrasive waterjet is ideal for making internal cutouts in glass as it
effectively pierces through most thicknesses, and produces
exceptional edge quality. Today, this technology is used globally
for many glass processing applications, including:
-power point cutouts
-kitchen and bathroom splashbacks
-mirrors
-table top inlays
-window panels
-frameless shower screens.

31. Cutting of wood
Waterjet cutting is a highly effective, yet very gentle cutting method. A
waterjet does not cause any thermal or chemical changes in the
material, and there is no burning, melting, gas or slag formation,
cracking or fracturing during the process, so its the best choice when
cutting wood

32. Cutting of Rubber & Composites:
Waterjet cutting is used for many applications due to the speed,
reliability and exceptional edge quality waterjet offers. It is a
very popular process for cutting rubber, foam, fabric, insulation,
plasterboard, circuit boards, nappies, plastics, leather and
fibreglass as the process is very fast and there is little material
wastage.

33. CUTTING STONE & TILE
Whether you're cutting thick granite, marble, slate, limestone,
soapstone, travertine, engineered stone or any other material for floors
and counters; stones, porcelain, or ceramic tile for artistic work such as
inlays, signs or medallions; or glass and metal for artistic accents and
signage, the abrasive waterjet's unique ability to cut very intricate
designs at high speed without breakage frees your imagination and
expands your business. Compared to traditional cutting tools and CNC
machines, easy-to-use Flow waterjets dramatically reduce work-in-
process time for stone, glass and tile fabricators.

34. Cutting of Metal:
Waterjet is ideal for cutting a range of standard and exotic
metals including:
-Aluminium ,mild and stainless steel ,titanium,brass and
copper.
This is because waterjet creates a clean cut with exceptional
edge quality that does not require a secondary finishing,
making it one of the most versatile and efficient cutting
processes available today. Waterjet is also a cold cutting
process which means it is ideal for cutting metal as there are
no heat effected zones on any part of the workpiece.

35. Defence & Military Waterjet Cutting
Cutting applications for the defence and military industry include
shaping, armour plating, bullet-proof glass and composites.
Because waterjet is a cold cutting process it is one of the few processes
suitable for cutting these materials without changing molecular
structure and reducing strength.
The defence and military manufacturing industry depends on waterjet
cutting.

36. for the Aerospace Industry
Abrasive waterjet is used in the aerospace industry for cutting
materials such as brass, inconel, aluminium, titanium and
other exotic metals. As waterjet leaves an exceptional edge
quality it is works for items up to 200mm think, including;
-wing sections
-turbine blades
-brake components
-landing gear

37. Automotive industry
Waterjet cutting machines have been used for many years in the
automotive industry due to its ability to be integrated with robotic
systems.
Water-only cutting (no abrasive) is the preferred tool for production of
interior carpets, insulation, and head linings, as it produces minimal
material waste with no mess.

38. Limitations of WJM
- only soft materials can be machined
*so we have to add abrasive material like granite to increase efficiency
Limitations of AWJM
-Abrasive powder can't be reused because its cutting ability decreases
- can't cut very hard materials like diamonds
LIMITATIONS

39. General limitations
-The initial cost is very high (machine price starts from 50.000$ to 300.000$).
-You need industrial level of electricity to power the pump(some pumps
require 250 AMPS).
-The material removable rate is low.
-Greater thickness means less efficiency.
-Can't be used for mass production(because of high maintenance
requirements).

40. Ice Jet machining is a type of AWJM but the abrasives are
changed by ice particles, that form the ice jet. Since the
hardness of the ice particles are fewer than that of the
abrasives, minor material removal rates are expected,
compared to AWJM. However, the cost reduction and the
good environmental impacts make IJM even better. IJM is
used in the food, electronic, medical, and space industries
where contamination is impossible.
Ice Jet Machining (IJM)

41. ■ Environmentally friendly
■ No dust, fumes, or gases released
■ Better material utilization
■ Grinding and polishing are eliminated, reducing secondary operation costs.
■ There is no deflection to the rest of the work piece.
ADVANTAGES

42. ■ Fits multiple-axis systems
■ Cutting in all axes
■ No tool sharpening
■ The tool does not wear and, therefore, does not need sharpening
■ Easy programming with standard CAD/CAM systems
■ Easily adaptable to automatic contouring
■ Easily integrated into flexible production systems
■ Only simple fixtures required

43. ■ Just-in-Time production
■ Quick prototyping
■ Small tangential forces on cut material
■ Stress free cutting
■ No material jump-off
■ No heat affected zones
■ Cuts can be started at any location without the need for predrilled holes.

44. WJM vs. OTHER MODERN PROCESSES
-Water jets are much faster than EDM.

45. •About waterjets, archived from the original on 2010-02-14, retrieved 2010-02-13.
•^ Fourness, Charles A et al, Paper Metering, Cutting, and Reeling Archived 2014-02-19 at the Wayback Machine, filed May 22, 1933,
and issued July 2, 1935.
•^ Johnson, Carl Olof, Method for Cutting Up Plastic and Semi-Plastic Masses Archived 2014-01-30 at the Wayback Machine, filed
March 13, 1956, and issued April 14, 1959.
•^ Schwacha, Billie G., Liquid Cutting of Hard Metals Archived 2014-01-30 at the Wayback Machine, filed October 13, 1958, and
issued May 23, 1961.
•^ Jenkins, Dennis R & Tony R Landis, Valkyrie: North American's Mach 3 Superbomber, Specialty Press, 2004, p. 108.
•^ Rice, Phillip K., Process for Cutting and Working Solid Materials Archived 2014-01-31 at the Wayback Machine, filed October 26,
1962, and issued October 19, 1965.
•^ Leach, S.J. and G.L. Walker, The Application of High Speed Liquid Jets to Cutting, Philosophical Transactions of the Royal Society of
London Series A, Mathematical and Physical Sciences, Vol 260, No 1110, July 28, 1966, pp. 295–310.
• ^ Franz, Norman C., High Velocity Liquid Jet Archived 2014-01-31 at the Wayback Machine, filed May 31, 1968, and issued August
18, 1970.
References

46. THANK YOU
Created by Hassan Ahmed Abdullrazeq