mp ppt final
DESCRIPTION
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 manufacturingTRANSCRIPT
Unconventional machining process
BY: Krishna jadhav
(134110027) Pratik gode
(134110028) Sandesh thoke
(134110029) Sushmita sarnaik
(134110030)
NONTRADITIONAL MACHINING PROCESS
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
I. Chemical machiningII. Electrochemical Machining ProcessesIII. Mechanical Energy ProcessesIV. Thermal energy processes
NONTRADITIONAL MACHINING AND THERMAL CUTTING PROCESSES
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
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
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)
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.
Diagram of CHM
Work piece preparation Coating with masking material Scribing of the mask Etching Cleaning masking material
Steps of chemical machining
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
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
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.
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
• 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
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
Widely used to produce microcomponents. In industries like MEMS and semiconductor
industries. Complex parts and integrated circuits.
Applications
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
Material removal by anodic dissolution, using electrode (tool) in close proximity to the work but separated by a rapidly flowing electrolyte.
Electrochemical Machining (ECM)
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
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)
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
Adaptation of ECM to remove burrs or round sharp corners on holes in metal parts produced by conventional through‑hole drilling
Electrochemical Deburring (ECD)
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
Electrochemical machining
Electrochemical grinding
Electrochemical debburing
Ultrasonic machining Water jet cutting Abrasive jet machining Abrasive water jet cutting
lll.Mechanical Energy Processes
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)
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
Uses a fine, high pressure, high velocity stream of water directed at work surface for cutting.
Water Jet Cutting (WJC)
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
High velocity stream of gas containing small abrasive particles
Abrasive Jet Machining (AJM)
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
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)
Ultrasonic Processes
Water jet machining
Abrasive jet machining
Abrasive water jet machining
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
Electric discharge machining Electric discharge wire cutting Electron beam machining Laser beam machining Plasma arc machining
Thermal Energy Processes
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
Electric discharge machining (EDM): (a) overall setup, and (b) close‑up view of gap, showing discharge and metal removal
Electric Discharge Machining (EDM)
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
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
Uses the light energy from a laser to remove material by vaporization and ablation
Laser Beam Machining (LBM)
Uses a plasma stream operating at very high temperatures to cut metal by melting.
Plasma Arc Cutting (PAC)
Laser beam machining
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.
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