Ultrasonic Machining

Ultrasonic Machining

Introduction

         Ultrasonic machining, is a manufacturing process that removes material from the surface of a part through high frequency and low amplitude vibrations of a tool against the material surface in the presence of fine abrasive particles.

The fine abrasive grains are mixed with water to form a slurry that is distributed across the part and the tip of the tool.

Important parameters

•Frequency :  about 20000 to 30000 Hz

•Amplitude :  0.05 to 0.125 mm 

•Tool material :  Steel, stainless steel etc.

•Abrasive material : Silicon carbide, aluminum oxide, boron carbide

•Material of operation : Brittle and hard material

•Transducer material : Nickel or Nickel alloys 

Schematic diagram

Part Introduction

• Power Source: 

High frequency high voltage power supply require for this process. This unit

converts low frequency electric voltage (60 Hz) into high frequency electric

voltage (20 kHz).

•Transducer: 

Transducer is a device which converts electric single into mechanical vibration.

•Booster: 

The mechanical vibration generated by transducer is passes through booster

which amplify it and supply to the horn.

Tool holder/Horn: 

As the name implies this unit connects the tool to the transducer. It transfers amplified vibration from booster to the tool. It should have high endurance limit.

Working Principle 

        First the low frequency electric current passes through electric supply. This

low frequency current converts into high frequency current through some

electrical equipment.

This high frequency current passes through transducer. The transducer converts

this high frequency electric single into high frequency mechanical vibration.

This mechanical vibration passes through booster. The booster amplify this high

frequency vibration and send to horn.

Horn which is also known as tool holder, transfer this amplified vibration to tool

which makes tool vibrate at ultrasonic frequency.

As the tool vibrates, it makes abrasive particle to vibrate at this high frequency.

This abrasive particle strikes to the work piece and remove metal form it.

Advantages of USM

•Hard material can be easily machined by this method.

•No heat generated in work so there is no problem of work hardening or change in structure of workpiece.

•Non-conductive metals or non-metals, which cannot be machined by ECM

of EDM can be machined by it.

Disadvantages of USM

•It is quite slower than other mechanical process.

•Tool wear is high because abrasive particle affect both work-piece and

tool.

•It can machine only hard material, Ductile metal cannot be machine

by this method.

•It cannot used to drill deep hole.

Applications of USM

•This machining is used to machine hard and brittle material like

carbide, ceramic, glass etc.

•This is used in machining of die and tool of drill, wire drawing

machine etc.

•Used in fabrication of silicon nitrite turbine blade.

•It is used to cut diamond in desire shape.