Exam Review Flashcards by Tina Ko

which one of the following processes can NOT print in full color?
a. material jetting
b. directed energy deposition
c. binder jetting
d. sheet lamination

b. DED

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Which one of the following processes can NOT effectively print assemblies with functional kinematic joints?
a. selective laser sintering
b. extrusion
c. binder jetting
d. sheet lamination

d. sheet lamination

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which one of the following is NOT a relative advantage of material jetting processes?
a. multi-material printing
b. speed
c. available material options
d. cost
e. color

c. available material options

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In Material Jetting processes, the conversion of liquid material droplets to solid geometry
should occur during flight or soon after impact
T or F

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Which of the following is NOT one of the technical challenges in material jetting processes?
a. droplet formation
b. droplet deposition control
c. droplet shape
d. droplet density

c. droplet shape

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Which Material Jetting droplet creation mode uses timed pressure pulses created from
thermal, piezoelectric, electrostatic, or other actuation devices?
a. spray
b. continuous
c. direct
d. drop-on-demand

d. drop-on-demand

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Which Material Jetting droplet formation mode can achieve higher placement accuracy?

drop-on-demand

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Which Material Jetting droplet formation mode can achieve higher throughput?

continuous

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In Material Jetting processes, a low value of the printing indicator means the flow is
dominated by viscosity
T or F

True

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In Material Jetting processes, supports are required for any overhang geometry
T or F

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A Material Jetting 3D printer could likely print a 0.5 mm pin feature projecting from a face.
T or F

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In Binder Jetting processes, the unprinted powder is not recyclable
T or F

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Parts built using a Binder Jetting process have better dimensional accuracy than parts built
using Powder Bed Fusion processes
T or F

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Which one of the following is NOT a characteristic of a good binder material?
a. easily printable
b. good adhesion
c. high thermal conductivity

c. high thermal conductivity

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After high temperature sintering in metal Binder Jet post-processing, the part is fully dense.
T or F

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Compared to fully dense parts of uniform composition Binder Jet printed parts with infiltrants
added in post-processing to achieve full density have
a. higher elongation (ductility)
b. lower elongation

b. lower

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Which of the following is not an advantage of Binder Jet processes?
a. self-supported overhangs
b. parts nested
c. assemblies and kinematic joints printed
d. good accuracy and surface finish
e. range of material compositions

d. accuracy and surface finish

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For Binder Jet processes, detail feature size is limited by part strength in the green state
rather than print resolution
T or F

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In Binder Jetting processes, supports are required for overhang geometry
T or F

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A Binder Jetting 3D printer could likely print a 0.5 mm pin feature projecting from a face.
T or F

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Form-then-bond sheet lamination processes require an alignment system to ensure each
bonded layer is properly registered.
T or F

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Bond-then-form sheet lamination processes exhibit homogeneous mechanical and thermal
properties
T or F

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Bond-then-form sheet lamination processes require external supports for overhang features
T or F

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In a bond-then-form sheet lamination process control of the part’s accuracy in the z-direction
(build direction) is difficult
T or F

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Thermal residual stresses and thermally induced deformation due to resolidification of molten metals are a major concern in Ultrasonic Additive Manufacturing. T or F

Which of the following is NOT a type of common defect that occurs in Ultrasonic Additive Manufacturing a. incomplete bond due to insufficient energy at layer/layer interface b. broken bond due to excess energy at layer/layer interface c. damage within foil within a layer d. gaps/overlaps between adjacent foils within a layer

Which controllable Ultrasonic Additive Manufacturing process parameter determines the amount of energy available for bond formation?

oscillation amplitude

The primary measure of bond quality in Ultrasonic Additive Manufacturing is

linear weld density

Which one of the following conditions is NOT necessary for high quality layer bonding in Ultrasonic Additive Manufacturing? a. atomically clean metal surfaces b. close contact between surfaces c. high temperature d. plastic deformation at foil interface

Which Directed Energy Deposition process should be used for high deposition rates of simple, blocky geometries?

wire feed

In Directed Energy Deposition processes, the microstructure can be predicted by calculating which TWO of the following? a. solidification rate b. material deposition rate c. thermal gradient d. residual stresses

a. solidification rate c. thermal gradient

Relative to Powder Bed Fusion processes, Directed Energy Deposition processes have a. lower ability to produce small scale features b. higher ability to produce small scale features

100% feedstock capture efficiency is possible in wire-fed feed Directed Energy Deposition processes. T or F

Decreasing the scan speed in Directed Energy Deposition processes increases the melt pool size, leading to slower cooling. T or F

In Directed Energy Deposition processes, which of the following parameter changes will decrease deposit thickness? a. increasing beam power b. decreasing beam power

In Directed Energy Deposition processes, which of the following parameter changes will increase deposit thickness? a. increasing traverse speed b. decreasing traverse speed

Directed Energy Deposition processes can perform multi-axis material deposition because the kinetic energy of the powder particles being fed from the powder nozzle into the melt pool is greater than the effect of gravity on powders during flight. T or F

Which of the following is NOT a reason Directed Energy Deposition processes are well suited for component repair? a. can be integrated with CNC mill so additive and subtractive processing is possible b. very high resolution geometric features can be added to existing parts c. multi-axis material deposition is possible d. easier to accurately control the motion of the deposition head than the substrate

Units can be specified in an STL file T or F

In a direct digital manufacturing company, formal part certification is required and equipment, personnel, fabrication processes, and quality systems must go through formal qualification procedures. T or F

Which one of the following is NOT a motivation for direct digital manufacturing? a. complex shapes b. digital record c. fast turnaround d. lot size of one is economical e. electronic spare parts f. no hard tooling g. low recurring costs h. unique customized shapes

In Additive Manufacturing, traditional design for manufacture rules do not generally apply while traditional design for assembly rules still apply. T or F

A multi-part kinematic assembly printed pre-assembled is primarily an example of which type of complexity? a. shape b. hierarchical c. material d. functional

An STL file contains 4 faces and 7 edges. Is it valid?

no face/edge = 2/3

Which of the following is an example of a meso-structure? a. flange b. frame c. lattice d. dendrite

Which of the following quantities is NOT included in a build time estimate? a. scan or deposition time b. transition time between layers c. delay time d. post-processing time

Which of the following is NOT a main category included in the high level cost model for additive manufacturing? a. machine purchase b. machine operation c. inflation d. material e. labor

which material jetting droplet formation mode can achieve smaller drop size? a. spray b. continuous c. direct d. drop-on-demand

which material droplet formation mode requires material to be able to carry an electric charge? a. continuous b. drop-on-demand

In MJ processes, if the print material is not in liquid form to begin with it must be formulated as a liquid. Which of the following is NOT a method used to form a liquid material: a. suspending particles in carrier liquid b. condensation c. mixing a formulation of monomer or pre-polymer with a polymerization initiator d. dissolving material in a solvent e. melting a solid polymer

In MJ processes, the printing indicator relates all of the following characteristics to predict printing success except: a. inertial b. viscous c. surface tension d. pressure e. geometric

In material jetting, a high value of printing indicator means the flow is dominated by surface tension T or F

Binder jetting processes build parts faster than material jetting because only a small fraction of the part volume is dispensed T or F

parts build using a binder jetting process are frequently post-process with an infiltrant to improve mechanical properties T or F

binder jetting processes produced a better surface finish than material jetting processes T or F

which of the following processes can print in full color? a. material jetting b. extrusion c. binder jetting d. sheet lamination e. directed energy deposition

a, c, d

what is the correct order of the 3 furnace cycles in metal binder jet post-processing?

debind, sinter, infiltrate

which of the following is NOT an advantage of a bond-then-form sheet lamination process? a. low shrinkage b. low post-processing time c. small part feature detail d. non-toxic, stable, material feedstock e. low material, machine, process costs f. z-direction accuracy

b, c, f

which one of the following is NOT an advantage of a form-then-bond sheet lamination process? a. construction of parts with internal features and channels b. no danger of cutting into previous layer c. external support for overhanging features d. less demanding laser power control or knife pressure e. no decubing process

which one of the following mechanisms is NOT used to achieve bonding in sheet lamination processes? a. adhesive bonding b. clamping c. thermal bonding d. electric arc welding e. ultrasonic welding

which one of the following is NOT an advantage of Ultrasonic Additive Manufacturing? a. dimensional accuracy b. automated support material c. part complexity d. build temperature

In UAM, exposure time is determined by the normal force of the sonotrode T or F

Which one of the following is NOT a cause of anisotropy in parts made from Ultrasonic Additive Manufacturing? a. directional grain flow in rolled metal foils b. high temperature c. defects along foil-to-foil interface d. interfacial plastic deformation

The solidification rate is the key characteristic to control in directed energy deposition processes because it, along with the thermal gradient, determines the microstructure that is developed T or F

which of the following parameters does NOT affect the deposit thickness in directed energy deposition processes? a. laser focal plane location with respect to surface b. scan pattern c. laser power d. powder feed rate e. beam scan speed

In DED processes, the height and volume of the deposit melt pool dynamically changes in the first few layers depending on the focal length location with respect to the substrate surface and process parameters chosen T or F

which of the following should NOT be considered when selecting a secondary support material for Material Jetting and Material Extrusion processes? a. ease of removal b. color c. material printability d. material compliance e. solvent safety

additive manufacturing processes exhibit larger shrinkage in the x-y plane than in the z-direction because there is a time gap between layers T or F

units must be specified in an STL file T or F

triangulated mesh geometry in AMF files is prone to gaps that break the watertight surface boundaries because vertices are redundantly defined for each facet T or F

In a watertight tessellated surface mesh such as in an STL file, the ratio of the number of faces to the number of edges must be a. 1/2 b. 2/3 c. 3/4 d. 3/2

The alternative file format that supports curved triangles, textured surfaces, colors, and multiple materials is known as..

AMF

AM enables mass customization because no hard tooling or fixtures are required T or F