This document provides an overview of water jet and abrasive water jet machining processes. It discusses how water jet machining works by using high pressure water to cut materials. It then explains how abrasive water jet machining incorporates abrasive materials into water jets to increase cutting speed and the range of cuttable materials. The document outlines several applications for each process and compares them to other machining methods like lasers and milling. It also discusses factors that influence the cost of operating water jet systems and predicts continued growth and advances in water jet technology in the future.

1. REPUBLIC OF TURKEY
YILDIZ TECHNICAL UNIVERSITY
DEPARTMANT OF MECHANICAL ENGINEERING
WATER JET AND ABRASIVE WATER JET MACHINING
PROCESSES
MURAT ATAK
MAY 2016, ISTANBUL

2. CONTENTS
 Nontraditional machining process
 Water jet machining
 Applications of water jet machining
 Abrasive waterjet machining
 Applications of abrasive water jet machining
 Water jet vs Lasers /Milling/Punch Press
 Cost of Water jet Cutting
 Future of Water jet Machining

3. Nontraditional Machining Process
 Non-traditional manufacturing processes is defined as a group of processes that remove excess
material by various techniques involving mechanical, thermal, electrical or chemical energy or
combinations of these energies but do not use a sharp cutting tools as it needs to be used for
traditional manufacturing processes.
 Extremely hard and brittle materials are difficult to machine by traditional machining processes
such as turning, drilling, shaping and milling. Non traditional machining processes, also called
advanced manufacturing processes, are employed where traditional machining processes are not
feasible, satisfactory or economical due to special reasons as outlined below.

4.  Very hard fragile materials difficult to clamp for traditional machining
 When the workpiece is too flexible or slender
 When the shape of the part is too complex Several types of non-traditional machining processes have been
developed to meet extra required machining conditions. When these processes are employed properly, they offer
many advantages over non-traditional machining processes. The common non-traditional machining processes are
described in this section

5. WATER JET MACHINING
 Usage of water jets in manufacturing processes, has been known for many decades. A wide range of
engineering materials can be cut by water jets with satisfactory results. Enhanced reliability and efficiency of
the technique, have yielded the technology greater interest for manufacturing applications.
 Water jet cutting can reduce the costs and speed up the processes by eliminating or reducing expensive
secondary machining process. Since no heat is applied on the materials, cut edges are clean with minimal burr.
Problems such as cracked edge defects, crystalisation, hardening, reduced wealdability and machinability are
reduced in this process.

6. WJM has the following advantages:
 The process requires a limited volume of water (100–200 L/h).
 The tool (nozzle) does not wear and therefore does not need sharpening.
 It is ideal for cutting asbestos, glass fiber insulation, beryllium, and fi ber-reinforced plastics
(FRP), because the process provides a dustless atmosphere. For this reason, the process is
not hazardous and is environmentally safe.
 The process provides clean and sharp cuts that are free from burrs.
WJM has the following disadvantages:
 WJM is unsafe in operation if safety precautions are not strictly followed.
 The process is characterized by high production cost due to
 The high capital cost of the machine
 The need for highly qualified operators
 WJM is not adaptable to mass production because of the high maintenance requirement.

7. Schematic illustration of WJM system
Process capabilities of water jet machining

8. APPLICATIONS OF WATER JET MACHINING
WJM is used on metals, paper, cloth, leather, rubber, plastics, food, and ceramics.

9. ABRASIVE WATER JET MACHINING PROCESS
 AWJM is a hybrid process (HP) since it is an integration of AJM and WJM processes. The addition of
abrasives to the water jet increases the range of materials which can be cut with a water jet drastically and
maximizes the MRR of this HP.
 AWJM process is capable of machining both soft and hard materials at very high speeds as compared
with those realized by WJM. It cuts 10–50 times faster than WJM process. Moreover, the cuts
performed by AWJM have better edge and surface qualities.

10. Advantages of abrasive water jet machining technology;
 There is no thermic effect on the material, and there are no changes in its structure
 Minimum influence of jet power on the material, and there are no micro-cracks
 There are no chemical effects on the material
 It is possible to cut layered materials with very complex characteristics of individual
layers and composites
 Quality finish; Materials cut by the abrasivejets have a smooth, satin-like finish,
similar to a fine sandblasted finish.
Disadvantages of abrasive waterjet machining technology:
 In the process of high-speed cutting of linear angles, water jet may cause indents in the material
 Materials affected by corrosion must be protected from corrosion after cutting

11. APPLICATIONS OF ABRASIVE WATER JET MACHINING
Abrasive waterjet has the ability to cut almost all materials and thickness. Most uses are for cutting of specialty
materials such as stainless steel and aluminium.Its flexibility makes it useful for all applications.
The AWJ machining operations consist of cutting, multi-axis machining, milling, turning, drilling, polishing, etc.
Awjm milling Awjm turning

12. COMPARISON BETWEEN WATER JET MACHINING AND OTHER PROCESSES
WATER JETS VS LASERS
 Abrasive waterjets can machine many materials that lasers cannot.( Reflective materials in particular, such as
Aluminum and Copper)
 Uniformity of material is not very important to a waterjet
 Maintenance on the abrasive jet nozzle is simpler than that of alaser,though probably just as frequent.
After water jet cutting After laser cutting

13. WATER JETS VS MILLING
Waterjets can also machine almost any material, including brittle materials, pre-hardened materials, and
otherwise difficult materials such as Titanium, Hastalloy, Inconel, SS 304, and hardened tool steel.
WATER JETS VS PUNCH PRESS
Waterjets have a lower cost-per-piece for short runs than a die press, because of the expense (and time)
involved in creating the dies and punches. Creating the drawing for a part on a waterjet machine is all
that's needed to begin machining the part, where with a punch press, the drawing is usually only the first
step to creating the die.

14. COST OF WATER JET CUTTING
The cost to operate a waterjet is a common question, as people struggle to understand the
difference between running a typical plasma cutting machine and a waterjet cutter. There are
different consumables, different power requirements, cost of water, and most importantly, the cost
of abrasive.
To dig into this question a little deeper, looked at six different waterjet system configurations,
including:
60,000 PSI / 50 HP pump
60,000 PSI / 100 HP pump
60,000 PSI / 100 HP pump running two cutting heads
90,000 PSI / 60 HP pump
90,000 PSI / 125 HP pump
90,000 PSI / 125 HP pump running two cutting heads

15. Water Jet Cost Per Hour
For each of these, figured the cost of power, wear parts, water, and abrasive, on a cost-per-
hour basis, as shown in the chart below.
Water jet cost percante

16. FUTURE OF WATER JET MACHINING
In the next half-dozen years later, we can expect to see the following changes:
 More manufacturers
 More machines in different shops
 More engineers who understand water jets
 Easier maintenance
 Faster and more accurate machines
 Cheaper better mixing tubes
In the future, people will look back at the early 21st century as the beginning of the most exciting period
in the waterjet industry.
If future advances in waterjet technology rival those of the past few years, waterjet usage will experience
tremendous growth.

17. THANK YOU FOR LISTENING ….