Band Saw Machine, and Non-Traditional Manufacturing (Week 11) Flashcards
(37 cards)
What is a Band Saw Machine?
A bandsaw is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material.
What are the 4 main components of a Band Saw Machine?
- Head
- Column
- Table
- Base
What is the Cutting Tool of a Band Saw Machine?
Cutting Tool is a Blade (Saw)
Consists of Several Teeth
Can be Used for All Materials
Width of the Cut is Called the _________ and is small so the Process Wastes no Material
Width of the Cut is Called the [Kerf (slit)] and is small so the Process Wastes no Material
What are Saw Blades made from?
Carbides
High Carbon Steels
High Speed Steels
What is the typical function of a Band Saw?
Separate a work part into two pieces and cut off unwanted portions of the part.
Teeth have deviated in order to _________________ between the saw blade and part.
Teeth have deviated in order to [reduce Friction] between the saw blade and part.
Teeth type depend on the _________________
Teeth type depend on the [cutting material]
Tooth pattern determines the efficiency of a blade in various materials.
What tooth pattern is best for cutting most ferrous metals?
Standard Tooth Blade Pattern
What tooth pattern is best for cutting aluminum, magnesium, copper, and soft brasses?
Skip Tooth Blade Pattern
What tooth pattern is best for cutting most nonferrous metallic materials?
Hook Tooth Blade Pattern
What is the Three-Tooth Rule?
At least three teeth must be in contact with the work
- Large sections and soft materials require a coarse-tooth blade.
- Small or tin work and hard materials require a fine-tooth blade.
What is the difference between conventional & Nonconventional processes?
Non-conventional technologies refer to a group of processes that remove material NOT using a sharp/hard cutting tool like in conventional machining.
What are some other forms of energy used to remove or add material in Non-Traditional Machining?
Electricity
Heat energy
Light energy
electrochemical energy
chemical energy
sound energy
special mechanical energy
Why non-traditional technologies is important?
To machine newly developed difficult-to-cut materials: high strength, high hardness, and high toughness.
To machine complex part geometries, micro-surface, and low-stiffness parts. that are difficult or impossible to machine by traditional methods.
To avoid surface damage, such as stresses, created in conventional processes.
What is the difference between traditional and non-traditional
machining processes?
Traditional Machining Processes :
Use mechanical energy
Direct contact between the tool and the workpiece
Using a Sharp/Hard cutting tool
High tool wear
Non-Traditional Machining Processes :
Use chemical, electrical, or thermal energy
whereas unconventional machining does not.
NOT using a sharp/hard cutting tool
Minimal tool wear
What is Water Jet Machining (WJM)?
It uses a fine, high pressure, high velocity (500-1400 m/s) stream of water (~ Ø0.1- 0.4mm) directed at the work surface to cause cutting of the workpiece.
Cutting of all non-metallic
materials (food, composites,
plastics, fabrics, rubber,
wood, Rocks,…) and all metallic materials.
Can cut any material.
Electro-chemical Machining (ECM)
Electrochemical machining removes material from ________________________ workpiece by anodic dissolution. Workpiece geometry is obtained by a formed electrode tool that is in close proximity but separate.
In this process, particles travel from the anodic material (workpiece) toward the cathodic material (machining tool). A current of _________________ carries away the deplated material before it has a chance to reach the machining tool. The produced cavity is the mating image of the tool shape.
Its industrial application has been extended to:
*ECM machining
*ECM drilling
*ECM grinding
*ECM polishing
Electrochemical machining removes material from [an electrically conductive] workpiece by anodic dissolution. Workpiece geometry is obtained by a formed electrode tool that is in close proximity but separate.
In this process, particles travel from the anodic material (workpiece) toward the cathodic material (machining tool). A current of [electrolyte fluid] carries away the deplated material before it has a chance to reach the machining tool. The produced cavity is the mating image of the tool shape.
Its industrial application has been extended to:
*ECM machining
*ECM drilling
*ECM grinding
*ECM polishing
Electrical Discharge Machine (EDM)
Basics
The workpiece is removed by a series of sparks that cause localized melting and evaporation of the material in the presence of a ______________.
The workpiece is typically submerged in a dielectric bath of ________________________.
The workpiece is removed by a series of sparks that cause localized melting and evaporation of the material in the presence of a [dielectric fluid].
The workpiece is typically submerged in a dielectric bath of [deionized water or oil].
Electrical Discharge Machine (EDM)
How It Works
At the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage __________ an electric field in the insulating dielectric that is present in a narrow gap between the electrode and the workpiece. This causes ______________________ suspended in the dielectric to concentrate at the points of the strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high, the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing a small amount of material from the workpiece surface.
At the beginning of EDM operation, a high voltage is applied across the narrow gap between the electrode and the workpiece. This high voltage [induces] an electric field in the insulating dielectric that is present in a narrow gap between the electrode and the workpiece. This causes [conducting particles] suspended in the dielectric to concentrate at the points of the strongest electrical field. When the potential difference between the electrode and the workpiece is sufficiently high, the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing a small amount of material from the workpiece surface.
What is the difference between Dielectric and Electrolyte?
A dielectric should be an electrically non-conductor at normal conditions; however, it should behave as a good conductor after a breakdown.
An electrolyte should be a good conductor of electricity for completing the electrical circuit to allow a smooth flow of ions between electrodes
What are the Advantages of (I’m not sure whether this slide was referring to Non-Traditional Machining in general or EDM specifically)
Ability to machine complex shapes that would otherwise be difficult to produce with conventional cutting tools. Also, machining of extremely hard material to very close tolerances
Very small work pieces can be machined where conventional cutting tools may damage the part from excess cutting tool pressure.
There is no direct contact between tool and work piece. Therefore, delicate sections and weak materials can be machined without perceivable distortion.
Tapered holes may be produced, and very fine holes can be attained
Tool wear is zero, same tool can be used for producing infinite number of components.
High surface quality may be achieved.
No direct contact between tool and work material so there are no forces and residual stresses, and less heat is generated.
Q. In which of the following industries, Non-traditional machining methods play an important role?
a) Automobile
b) Aerospace
c) Medical
d) All of the mentioned
d) All of the mentioned
Q. Non-Traditional machining can also be called as ________
a) Contact Machining
b) Non-contact machining
c) Partial contact machining
d) Half contact machining
b) Non-contact machining
