Top Banner
Unconventional machining process
51

Mp Ppt Final

Jan 24, 2016

Download

Documents

PratikKhatmode

This powerpoint presentation will help students to know the concepts involved in manufacturing process of elements . It is also helpful to others who want to know about different processes involved in manufacturing
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Mp Ppt Final

Unconventional machining process

Page 2: Mp Ppt Final
Page 3: Mp Ppt Final

BY: Krishna jadhav

(134110027) Pratik gode

(134110028) Sandesh thoke

(134110029) Sushmita sarnaik

(134110030)

NONTRADITIONAL MACHINING PROCESS

Page 4: Mp Ppt Final

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 tool in the conventional sense

Nontraditional Processes Defined

Page 5: Mp Ppt Final

I. Chemical machiningII. Electrochemical Machining ProcessesIII. Mechanical Energy ProcessesIV. Thermal energy processes

NONTRADITIONAL MACHINING AND THERMAL CUTTING PROCESSES

Page 6: Mp Ppt Final

Need to machine newly developed metals and non‑metals with special properties that make them difficult or impossible to machine by conventional methods

Need for unusual and/or complex part geometries that cannot easily be accomplished by conventional machining

Need to avoid surface damage that often accompanies conventional machining

Why Nontraditional Processes are Important

Page 7: Mp Ppt Final

Mechanical ‑ erosion of work material by a high velocity stream

Electrical ‑ electrochemical energy to remove material (reverse of electroplating)

Thermal – thermal energy usually applied to small portion of work surface, causing that portion to be removed by fusion and/or vaporization.

Chemical – chemical etchants selectively remove material from portions of work part.

Classification of Nontraditional Processes by Type of Energy Used

Page 8: Mp Ppt Final

Material removal through contact with a strong chemical etchant

Processes include:◦ Chemical milling◦ Chemical blanking◦ Chemical engraving◦ Photochemical machining

All utilize the same mechanism of material removal

1.Chemical Machining (CHM)

Page 9: Mp Ppt Final

CHM history

• Oldest non-traditional machining method which is used to shape copper with citric acid in the Ancient Egypt in 2300 BC.

• Until the 19th century this process was widely used for decorative etching. The development of photography provided a new dimension to chemical machining.

• The main industrial application of chemical machining developed after the war. In 1953, North American Aviation (California USA) used the process to etch aluminium components for rockets.

Page 10: Mp Ppt Final

Diagram of CHM

Page 11: Mp Ppt Final

Work piece preparation Coating with masking material Scribing of the mask Etching Cleaning masking material

Steps of chemical machining

Page 12: Mp Ppt Final

Masking material which is called maskant is used to protect work piece surface from chemical etchant.

Polymer or rubberbased materials are generally used for masking procedure

‣The selected maskant material should have following properties

Maskants

Tough enough to withstand handling Well adhering to the workpiece surface & Easy scribing. Inert to the chemical reagent used Able to withstand the heat used during chemical

machining

Page 13: Mp Ppt Final

Workpiece material Masking material

Aluminium and alloys Polymer, Butyl rubber, neoprene

Iron based alloys Polymer, Polyvinyl chloride,Polyetilien butyl rubber

Nickel Polymer Neoprene

Magnesium Polymer

Copper and alloys Polymer

Titanium Polymer

Silicon Polymer

Masking materials for various chemical machined materials

Page 14: Mp Ppt Final

Etchants are the most influential factor in the chemical machining of any material.

Various etchant are available due to workpiece material.

The best possible etchant should have properties as follow

Etchants

High etch rate, Good surface finish, Minimum undercut.Compatibility with commonly used maskants.High dissolved-material capacity.Economic regeneration.Easy control of process.

Page 15: Mp Ppt Final

Material Chemical etchant

Concentration

Etching Temperature (°C)

Etch rate (mm/min)

Aluminium and alloys

FeCl3 12-18˚Bé (*)

49 0.013-0.025

Steel FeCl3 42˚ Bé 54 0.025

Nickel FeCl3 42˚ Bé 49 0.13-0.38

Magnesium HNO3 % 12-15 32-49 1.0

Silicon HNO3 --- 38-49 Very slow

Concentrations, etching temperatures for various materials in chemical machining

Page 16: Mp Ppt Final

• Easy weight reduction• Simultaneous material removal operation• No stress introduction to the workpiece• Low capital cost of equipment• Requirement of less skilled worker• The good surface quality

Advantages of chemical machining

Disadvantages of chemical machining

• Difficult to get sharp corner• Difficult to chemically machine thick material • Etchants are very dangerous for workers

Page 17: Mp Ppt Final

Maskant thickness is generally kept about 0.2 mm.

Etching depth is up to 10 mm is applied.

Accuracy of ±0.01to 0.015 mm can be obtained.

MRR for common materials is about 140 to 160 cm3/min.

Workpiece thickness is less than 10 mm can be suitably machined.

Common specifications of CHM

Page 18: Mp Ppt Final

Widely used to produce microcomponents. In industries like MEMS and semiconductor

industries. Complex parts and integrated circuits.

Applications

Page 19: Mp Ppt Final

Electrical energy used in combination with chemical reactions to remove material

Reverse of electroplating Work material must be a conductor Processes:

◦ Electrochemical machining (ECM)◦ Electrochemical deburring (ECD)◦ Electrochemical grinding (ECG)

II. Electrochemical Machining Processes

Page 20: Mp Ppt Final

Material removal by anodic dissolution, using electrode (tool) in close proximity to the work but separated by a rapidly flowing electrolyte.

Electrochemical Machining (ECM)

Page 21: Mp Ppt Final

Can be perform on all conducting materials. Machining of heat-resisting alloys, cavities

in forging Multiple hole drilling. It can be used for DIE-SINKING operation. Drilling a jet engine turbine blade.

Applications of ECM

Page 22: Mp Ppt Final

Special form of ECM in which a grinding wheel with conductive bond material is used to augment anodic dissolution of metal part surface

Electrochemical Grinding (ECG)

Page 23: Mp Ppt Final

Any material which is electrically conductive.

Hardened steel, cemented carbides & similar materials.

Mainly applied to resharpening tools which are difficult to grind.

Applications of ECG

Page 24: Mp Ppt Final

Adaptation of ECM to remove burrs or round sharp corners on holes in metal parts produced by conventional through‑hole drilling

Electrochemical Deburring (ECD)

Page 25: Mp Ppt Final

ECD removes metal by non-contact, Electrochemical action.

Method is fast, highly selective & safe. Uses a low voltage, DC current & non-toxic

electrolytes. Material is remove in fine metal hydroxide

particles which can be further filtered & removed .

Working of ECD

Page 26: Mp Ppt Final

Electrochemical machining

Page 27: Mp Ppt Final

Electrochemical grinding

Page 28: Mp Ppt Final

Electrochemical debburing

Page 29: Mp Ppt Final

Ultrasonic machining Water jet cutting Abrasive jet machining Abrasive water jet cutting

lll.Mechanical Energy Processes

Page 30: Mp Ppt Final

Abrasives contained in a slurry are driven at high velocity against work by a tool vibrating at low amplitude and high frequency

Tool oscillation is perpendicular to work surface Tool is fed slowly into work Shape of tool is formed in part

Ultrasonic Machining (USM)

Page 31: Mp Ppt Final

Hard, brittle work materials such as ceramics, glass, and carbides.

Also successful on certain metals, such as stainless steel and titanium.

Shapes include non-round holes, holes along a curved axis.

Cutting of industrial diamonds.

USM Applications

Page 32: Mp Ppt Final

Uses a fine, high pressure, high velocity stream of water directed at work surface for cutting.

Water Jet Cutting (WJC)

Page 33: Mp Ppt Final

Usually automated by CNC or industrial robots to manipulate nozzle along desired trajectory.

Used to cut narrow slits in flat stock such as plastic, textiles, composites, floor tile, carpet, leather, and cardboard.

Not suitable for brittle materials (e.g., glass). WJC advantages: no crushing or burning of work

surface, minimum material loss, no environmental pollution, and ease of automation.

WJC Applications

Page 34: Mp Ppt Final

High velocity stream of gas containing small abrasive particles

Abrasive Jet Machining (AJM)

Page 35: Mp Ppt Final

Usually performed manually by operator who directs nozzle

Normally used as a finishing process rather than cutting process

Applications: deburring, trimming and deflashing, cleaning, and polishing

Work materials: thin flat stock of hard, brittle materials (e.g., glass, silicon, mica, ceramics)

Application of AJM

Page 36: Mp Ppt Final

When WJC is used on metals, abrasive particles must be added to jet stream usually

Additional process parameters: abrasive type, grit size, and flow rate◦Abrasives: aluminum oxide, silicon

dioxide, and garnet (a silicate mineral)◦Grit sizes range between 60 and 120

Abrasive Water Jet Cutting (AWJC)

Page 37: Mp Ppt Final

Ultrasonic Processes

Page 38: Mp Ppt Final

Water jet machining

Page 39: Mp Ppt Final

Abrasive jet machining

Page 40: Mp Ppt Final

Abrasive water jet machining

Page 41: Mp Ppt Final

Very high local temperatures. ◦ Material is removed by fusion or vaporization

Physical and metallurgical damage to the new work surface.

In some cases, resulting finish is so poor that subsequent processing is required.

lV. Thermal Energy Processes

Page 42: Mp Ppt Final

Electric discharge machining Electric discharge wire cutting Electron beam machining Laser beam machining Plasma arc machining

Thermal Energy Processes

Page 43: Mp Ppt Final

Metal removal by a series of discrete electrical discharges (sparks) causing localized temperatures high enough to melt or vaporize the metal

Can be used only on electrically conducting work materials

Two main processes:1. Electric discharge machining 2. Wire electric discharge machining

Electric Discharge Processes

Page 44: Mp Ppt Final

Electric discharge machining (EDM): (a) overall setup, and (b) close‑up view of gap, showing discharge and metal removal

Electric Discharge Machining (EDM)

Page 45: Mp Ppt Final

Tooling for many mechanical processes: molds for plastic injection molding, extrusion dies, wire drawing dies, forging and heading dies, and sheet metal stamping dies

Production parts: delicate parts not rigid enough to withstand conventional cutting forces, hole drilling where hole axis is at an acute angle to surface, and machining of hard and exotic metals

EDM Applications

Page 46: Mp Ppt Final

Special form of EDM that uses small diameter wire as electrode to cut a narrow kerf in work

Wire EDM

Electric discharge wire cutting (EDWC), also called wire EDM

Page 47: Mp Ppt Final

Uses the light energy from a laser to remove material by vaporization and ablation

Laser Beam Machining (LBM)

Page 48: Mp Ppt Final

Uses a plasma stream operating at very high temperatures to cut metal by melting.

Plasma Arc Cutting (PAC)

Page 49: Mp Ppt Final

Laser beam machining

Page 50: Mp Ppt Final

 Manufacturers of machine 

NAME OF MACHINE MANUFACTURERS LOCATION

Ultrasonic machine  Ravira ever green Pvt. Ltd.

Jaipur.

Ultrasonic machine Johnson plastosonic Pvt.Ltd

Pune.

Water jet machine K & K engineers Delhi.

Abrasive jet machine R. K. Transonic Pvt. Ltd

Noida.

Abrasive water jet machine

Kp Tech Machine Pvt. Ltd

Ahmedabad.

Page 51: Mp Ppt Final

 Manufacturers of machine 

NAME OF MACHINE

MANUFACTURERS LOCATION

Electrochemical machine

Janetta Enterprise. Bharuch, Gujrat.

Electrochemical grinding

Consort India. Noida, Uttar pradesh

Electrical discharge machine

USHA Tech. New Delhi.

Electron beam machine

Sahajana Tech. Ltd. Gandhinagar, Gujrat.

Plasma arc machine Mysore tech Tumkar,karnataka.

Laser beam machine Wuxi Label electronics

Jiangsu, China