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