ME 151 Review Chapter 19, 20, 28
What are some typical advantages of nontraditional machining processes?
-Able to machine with tight tolerances -Little to no residual stresses -Able to create complex or delicate geometry -Able to machine brittle, strong, and hard materials
What are some disadvantages of Electrochemical Machining?
-Difficult to create sharp corners -environmetally harmful by-products -expensive tooling
What are functions of the dielectric fluid in Electrical Discharge Machining?
-Flushing away debris -Electrical Insulator -Local Spark Conductor -Coolant
4 basic components of any machining process is:
-Machine tool -work-piece -Workholding Device -Cutting Tool
Limitations of machining processes are:
-Residual stresses (/distortion of unwanted final part) -Burrs(sharp chips around hole) -Delicate geometries may be difficult
7 processes are:
-Turning -Sawing -Broaching -Grinding -Milling -Drilling -Shaping -Planing
4 groups of material removal using NTM processes are:
-chemical -electrochemical -thermal -mechanical
Which of the following methods is used to pattern live cells during organ printing?
-inkjet deposition
What are some major disadvantages of fused deposition modeling process?
-relatively long build times -high material cost -limited to low strength materials
What method of Nontraditional machining is commonly used in the making of circuit boards?
Chemical Machining
Med- friction is _______ chip formation
Continuous :/
Most friction is _______ chip formation
Continuous with built edge :(
______ _______ determine final quality
Cutting Parameters
___ ____ is the primary cutting motion
Cutting Speed(V)
_____ _ ____ is the distance tool engages workpiece
Depth of Cut(DOC)
Least friction is _______ chip formation
Discontinuous :)
______ is important in determining type of chip produced
Ductility
The primary difference between Abrasive Waterjet Cutting and Abrasive Jet Cutting is the type of abasive particles used in the process.
FALSE
Powder-based processes are typically considered to be the most wasteful of the additive manufacturing methods
False
____ _____ is the amount of material removed per revolution or per pass of tool over workpiece
Feed Rate (Fr, Fm)
_______ Vibration is repeated input that causes vibration, with constant amplitude over time
Forced://
_______ Vibration is some input causes temporary vibration that decreases over time
Free :/
High ductile materials mean long continuous chips which means ____ friction which means heat formation and increases required force
High
_____ _____ materials require larger forces which increases deflection, friction(operating temp), and work input
High Strength (Sy)
The poor surface finish in the products using selective laser sintering or electro beam sintering is caused by
High porosity in the sintered material
What is a major disadvantage of laminated object manufacturing
Large amount of material waste
Material Removal Rate (MRR) formula:
MRR=Volume of cut/cutting time
_______ is the process of removing unwanted material from a workpiece in the form of chips to obtain a desired destination
Machining
Advantages of NTM
Review Notes Chp 28
________ Vibration is the repeated input @ natural frequency of system amplitude increases over time
Self-Excited
The 3 sources of heat are:
Shear zone (plastic deformation), chip interface contact region (plastic deformation and friction), and tool flank (friction)
Cutting Time(Tm) formula
Tm= (L+Allowance)/(frNs)
Electron Beam, Ion Beam Machining, Laser Machining, and Plasma Arc cutting are all thermal machining processes that rely on a focused beam of energy to locally melt or vaporize material on a work piece.
True
One of the advantages of chemical machining is that it can be used to machine very large surfaces simultaneously
True
The final additive process was invented in the 1980s and was limited to creating parts from a brittle photocurable polymer
True
The main difference between electrochemical machining and electrical discharge machining is that in electrochemical machining, electricity is used to produce a chemical (etching) reaction, but in EDM electricity is used to produce a thermal reaction.
True
Material Removal Rate is the:
Volume of material removed over time
Abrasive particles used in non-traditional mechanical processes are usually made of what material?
ceramics
2 types of chips:
continuous and discontinuous
Power put into the process is largely converted to____, which elevates the _________ of the chip, workpeice, tool, and cutting fluid
heat, temperature
Many materials are difficult to machine including:
high strength/high hardness
Machinists handbooks are ________ handbooks
reference
Cutting time is the :
time required to perform a cut
Structure and compostion affect _____ _____
tool wear