Water Jet Machining

Water Jet Machining

Introduction

            Water jet machining is process of removing unwanted material from workpiece by means of high pressure fluid with or without abrasive material.

In water jet machining, high velocity water jet is allowed to strike a given workpiece. During this process, its kinetic energy is converted to pressure energy. This induces a stress on the workpiece. When this induced stress is high enough, unwanted particles of the workpiece are removed.

Block Diagram

Part Introduction

•Reservoir: Storing water that is to be used in the machining operation.

•Pump: It pressurize  the water from the reservoir.

•Intensifier: Connected to the pump. It intensifies the water to a desired level.

•Accumulator: Temporarily store 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:  Discharge water to the workpiece at high velocity.

Working principle

•Water from the reservoir is pumped to the intensifier using a hydraulic pump.

•The intensifier increases the pressure of the water to the required level.

Usually, the water is pressurized to 200 to 400 MPa.

•Pressurized water is then sent to the accumulator. The accumulator

temporarily stores the pressurized water.

•Pressurized water then enters the nozzle by passing through the control valve

and flow regulator.

•Control valve controls the direction of water and limits the pressure of water

under permissible limits.

•Flow regulator regulates and controls the flow rate of water

•Pressurized water finally enters the nozzle.

•Here, it expands with a tremendous increase in its kinetic energy.

•High velocity water jet is produced by the nozzle.

•When this water jet strikes the workpiece, stresses are induced. These stresses

are used to remove material from the workpiece.

Advantages of WJM

1) Water jet machining is a relatively fast process.

2) It prevents the formation of heat affected zones on the workpiece.

3) It automatically cleans the surface of the workpiece.

4) WJM has excellent precision.

5) It does not produce any hazardous gas.

6) It is eco-friendly

Disadvantages of WJM

1) Only soft materials can be machined.

2) Very thick materials cannot be easily machined.

3) Initial investment is high.

Applications of WJM

1) Water jet machining is used to cut thin non-metallic sheets.

2) It is used to cut rubber, wood, ceramics and many other soft materials

.

3) It is used for machining circuit boards.

 4) It is used in food industry.