Surface condition impacts part performancwe

AIRLINE/AIRCRAFT PARTS FINISHING
Surface Condition Impacts Part Performance
Burrs, edges can negatively influence function of components.
By David A. Davidson, Society of Manufacturing Engineers, Chair: Deburring, Edge-Finish
and Surface Conditioning Technology Committee
T
he role of mass finishing processes—such as
barrel tumbling, vibratory, centrifugal, and
spindle finishing—as a method for removal of
burrs, developing edge contour, and smoothing and
polishing parts has been well established and docu-
mented for many years. These processes have been
used in a wide variety of part applications to promote
safer part handling (by attenuation of sharp part
edges); improve the fit and function of parts when
assembled; and produce smooth, even micro-finished
surfaces to meet either functional or aesthetic crite-
ria or specifications. Processes for developing specif-
ic edge and/or surface profile conditions on parts in
bulk are used in industries as diverse as the jewelry,
dental, and medical implant sectors on up through
the automotive and aerospace fields.
Less well known and less clearly understood is the
role specialized variants of these types of processes
can play in extending the service life and perform-
ance of components in demanding manufacturing or
operational applications.
Industry has always been looking to improve sur-
face condition to enhance part performance, and this
technology has become much better understood in
recent years. Processes are routinely utilized to
specifically improve life of parts and tools subject to
failure from fatigue and to improve their perform-
ance. These improvements are mainly achieved by
enhancing part surface texture in a number of dif-
ferent, and sometimes complementary, ways.
In his recently published “Mass Finishing
Handbook” author LaRoux Gillespie a chapter titled
“Process Side Effects” notes some of these potential
improvements and comments on negatives that can
be caused by incorrect process selection:
“In addition to removing burrs and improving sur-
face finishes, mass finishing can at the same time
xx www.metalfinishing.com
Figure 1: Increasingly sophisticated methods for measuring sur-
face condition have been developed in recent years to assist
engineers in analyzing and understanding surface conditions
and textures and their relationship to part performance. Often,
these methods are used to understand how surface finish tex-
tures meet operational requirements after parts have been
machined and finished. As in the case shown above, they are
also used in forensic applications to measure current surface
condition in terms of determining potential remaining opera-
tional service life. The diagram shown here depicts a 1.5 mm x
7.5 mm of a gear tooth wear area. A computer-enhanced 3-D
characterization is shown on the diagram to the left; the two
diagrams to the right show a 2-D surface profile trace.The part
in question is part of a gear-box built by Hamilton Sundstrand
for the space shuttle. (Photo courtesy of Jack Clark; Zygo Corp.,
Middlefield, Conn.
Figure 2A and 2B: In before-and-after comparisons, burr
removal, hole-edge radius, and interior surface finish developed
by Abrasive Flow Machining method (AFM). In many applica-
tions, developing edge and interior hole surface quality are CTQ
(critical to quality) and overall performance of the part, espe-
cially if non-turbulent air flow and air-flow efficiency are impor-
tant part attributes. Easily discerned in the comparison of the
two close-up photographs is the isotropic surface finish charac-
teristic of the finished part. (Photo courtesy of Extrude-Hone
Corp., Irwin, Pa.)
Figure 3 — Surface finish values of the small holes seen along the
edge of the foil area of the blade here are critical to cooling of the
blade. Improved and less turbulent flow due to high quality of
interior hole surfaces can be critical to function and performance
of the part. (Photo courtesy of Extrude-Hone, Irwin, Pa.)

change other key attributes of parts, some for the
worse and others for the better. In addition to
removing burrs, mass finishing can:
• Radius or blunt part edges;
• change part dimensions (0.000050 in.–0.003 in.);
• change a part’s surface finish;
• compact a part’s surface pores;
• clean a part’s oily and dirty surfaces;
• remove oxides and heavy scale from parts;
• change a part’s flatness;
• prevent soldering (if wrong abrasives are used);
• create large compressive stresses in part;
• improve or worsen corrosion rates;
• change part luster;
• change part color;
• change friction;
• and decontaminate radioactive surfaces.
AEROSPACE EDGE/SURFACE QUALITY
CONCERNS
Sometimes, to fully understand the significance of
edge and surface quality issues, it is important to
understand the magnitude of the consequences
when edge and surface condition receive insufficient
attention. Gillespie, when summarizing some points
made in an aerospace forum regarding edge and
surface quality issues, noted that important service
and operational considerations can be heavily
impacted by edge and surface condition quality:
Fatigue life, stresses, and strain: Fatigue life
increases with decreasing surface roughness, and
smoother surfaces have less preload loss when they
are part of a mechanically fastened joint. Burrs
increase stress concentration at hole edges, which
already have three times the net section stress at the
edge. Therefore, removing burrs decreases stress con-
centration, which increases fracture resistance and
fatigue life. Lastly, burrs can interfere with proper
seating of mechanical fasteners, so removing them
reduces damage to fasteners and clamped components
during assembly.
Sharp corners increase stress concentration, so
increasing radii decreases stress concentration,
which increases fracture resistance and fatigue life.
If water creeps under interfaces via higher surface
roughness and fills up a cavity or interface, then
freezes, it could create high stresses and/or acceler-
ate material fracture, not to mention stress corro-
sion cracking at scores from the hidden, trapped
water/chemicals.
One author notes, “Sharp corners, burr holes, etc.
increase not only the stress but the strain as well.
Looking at the strain we can have three different
situations:
1. The strain can be inside the linear behavior.
(Under the yield limit).
2. The strain can be between the ultimate and the
yield limit.
3. The strain can reach the ultimate limit.
If the third situation is going to occur, the cracks
can develop because of material failure. In this case,
the crack can also reach the material’s “critical
value.” For this reason, round the corners, deburring
the holes, and finishing the surfaces will help to
pass from the third to the first situation.”
Almost without exception fatigue cracks start at
the surface of a part rather than internally. One pos-
sible reason may be that the highest stresses are
usually found at the surface (e.g., bending and tor-
sion) and the surface is vulnerable to stress raisers,
such as machining notches, scratches, and pits.
Surface finish affects the strength of a part subject-
ed to fatigue loading because most machining oper-
ations leave a notch pattern and fatigue cracks usu-
ally originate in a notch.”
Corrosion and coating impact: Poor surface
finish introduces millions of new points for crevice
corrosion on the surface. Also, a rough surface can
Figure 5: Impeller-like parts can be processed with Centrifugal
Barrel Finishing (CBF); Turbo-Finish (TAM), and Abrasive Flow
Machining (AFM) methods to produce uniform edge contours,
but part performance is enhanced by the isotropic and plateaud
surfaces created in the foil area of the part.
Figure 4: Aircraft engine vane segments can be deburred,
radiused, and are polished with a number of different methods.
These components processed with centrifugal barrel finishing
(CBF), which has developed needed edge and surface finishes
while developing high-quality surfaces with useful stress and
isotropic characteristics.

February 2007 xx
make it difficult to get good
results with non-destructive
testing methods like die pene-
trants—especially when the
roughness is in a pattern (such
as produced by flycutting or
milling). Rougher surfaces or
sharper exterior edges can
scratch coated or painted sur-
faces during assembly and might
allow hidden corrosion to spread
underneath what might tem-
porarily appear as good finishes.
The physics, electrochemistry,
etc., are well documented about
applying a coating to a sharp
edge. When using any type of
electrically catalyzed process
(anodizing, electrocoating, elec-
trostatic spray painting, etc.)
current density fluctuations pre-
vent the build-up of a uniform
coating thickness. Variations in
coating thickness have many
negative aspects, such as vari-
able friction at joint surfaces,
areas for localized corrosion, pit-
ting, galvanic cells, etc. Corrosion
fatigue and stress corrosion
cracking are obvious concerns.
Joint friction and preloads:
Also, with riveted structure, fric-
tion (due to the clamping force of
the fasteners) between faying
surfaces in a joint serves a cou-
ple important functions. First,
the friction provides a bit of
“shear preload”—the joint can
take a certain amount of shear
without loading the fasteners or
sheet in bearing. The greater
the friction, the more resistant
the joint will be to working loose
and smoking rivets. This ties in
nicely to the second function: high
frequency (engine) vibrations
throughout the structure are
damped or dissipated through
joint friction. The greater the fric-
tion, the greater the high-frequen-
cy-fatigue resistance of a mechan-
ically fastened joint.
If a burr is sitting between the
fastened sheets preventing good
contact of the faying surfaces,
much of this friction is lost. A
higher surface roughness will
lead to higher friction forces to
overcome when torquing a bolt.
This means that less preload (Fi)
will be developed, with a corre-
sponding decrease in load at
which gapping occurs [Fi/(1-C)],
which increases chances for
leaks (stuff coming out, or stuff
going in), and also leads to worse
fatigue performance (higher
alternating tensile stresses). A
higher surface roughness may
also lead to preload relaxation—
exacerbating all of the above.
As one reader noted, “This is
the classic ‘shanking and sheet
gapping’ syndrome, caused by
burrs and ‘liberated burrs’
[chips].” Rough surfaces provide
less surface area of contact, giv-
ing rise to higher and very local-
ized contact stresses. If flavored
with a little salt mixed in and
throw in some corrosion, this
could be a disaster.
Good seating: A fastener hole
with a good, sharp, burred corner
will have obvious problems with
seating when met with a fasten-
er that has a radiused junction
between head and shank. Poor
bonding of structures, in light-
ning strikes, can cause cata-
strophic local structural failure.
Static discharge: Sharp out-
side corners on structure act as
electrical charge concentrators,
and can be a static discharge haz-
ard. For the same reason, sharp
corners can cause undesirable
results in electroplating opera-
tions. One reader asks, “If an over-
ly rough surface causes corrosion,
could this joint develop a static
charge?” If there are two conduc-
tive metal surfaces separated by a
dielectric (oxide) and you add some
movement or vibration—presto—
static charge because of rough sur-
faces (as opposed to burrs).
Issues between moving
parts: Mating faces must be
finely machined (or finished) to:
Figure 6: Centrifugal bar-
rel finishing was used to
change the character of
surfaces on this titanium
test coupon. Centrifugal,
vibratory, and AFM meth-
ods are being used to
change surface character-
istics that can affect part
performance. The upper
coupon is typical of as
machined (milling cutter-
path or ground) surfaces
with a positively skewed
surface has been altered
to exhibit a plateaued
surface with attenuated
or blended peaks, shown
in the lower test coupon.
Figure 7: Centrifugal barrel machine
preparing to process aircraft vane seg-
ments, deburring vane edges and also
smoothing and polishing the foil surface
areas simultaneously. (Photo courtesy
of Tom Mathisen, MFI.)

• Avoid friction;
• avoid heat due to friction. Excessive heat may
change the properties of the material surface, with
unpredictable consequences;
• have better lubrication. The active film in a fine
machined surface will be more efficient because
there will be more surface in contact with the
lubricant. This will permit better heat transfer
from the part to the lubricant (there is a limit to
how fine a finish a surface should have. The auto-
motive industry intentionally adds some surface
patterns to hold the oil in internal combustion
engines;
• excessive roughness may develop high material
wear, leading to high play, and high replace fre-
quencies of the parts;
• roughness produces friction as stated above.
Friction can lead to electricity (tribo-electric
effect). Electricity can lead to corrosion.
Electrical issues: As noted above, friction
between rough surfaces will create electrical energy.
That energy can create an accelerated galvanic-cor-
rosion anode or cathode site, if all (most) other sur-
faces are coated or insulated. Burrs are sources of
static discharge.
Burrs and surface roughness will both interfere
with good, uniform surface contact between faying
surfaces in a mechanical joint. This increases the
electrical resistance of the joint and, if severe, can
cause problems with electrical bonding of structure;
interfering with effective grounding of electrical
equipment and/or antennae, and become a minia-
ture plasma cutter in the event of a lightning strike.
Current density due to sharp edges and burrs can
cut through protective coatings on mating surfaces
and radii, providing a minute area of “clean metal”
electrical path to drive corrosion dramatically worse
than if no protective coating were there to begin
with due to the extremely high resultant current
density. The hole-punching force of high current
density results in stress risers to enhance SCC and
corrosion fatigue. For aircraft assemblies, sharp
edges become spark over points whenever voltage is
applied (static, lightning strikes, etc.)
Hydraulic and gas leaks: Higher values of sur-
face roughness (and burrs) increase leakage rate
under/around gaskets and seals. Nipping gaskets,
seals, and O-rings on sharp edges during installation,
or scouring them on rougher surfaces during opera-
tion of rotating equipment, can accelerate leakage.
Sometimes a surface that is finished too well can
hinder sealing. O-rings need something to hold on to
—if your surface finish is too fine and the compres-
sion on the O-ring is too light, the O-ring is likely to
fail. In one industry, engineers specify 63ra for most
surfaces that will contact a secondary sealing ele-
ment. (They do, however, require flatness and sur-
face finish to an extreme on other parts—millionths
of an inch for mechanical seal faces). There are
times when a sharp edge is needed. Labyrinth seals
in gas turbines spring to mind, as do squealer tips
on compressor blades.
Peening issues: Excessive surface roughness can
sometimes be an indication of over-peening, which
negates the beneficial aspects of compressive resid-
ual stress. Aluminum and magnesium are especial-
ly prone to over-peening, which results in many
localized areas of increased stress. Problems with
fracture (stress intensity) and fatigue (crack nucle-
ation sites) are then possible/probable. Joint prob-
lems can arise from excessive surface roughness,
and over-peening is yet another method for creating
surface roughness.
Shot peening, mass finishing, surface polishing,
deburring, and rounding off all add a sustained com-
pressive stress into the material. This stress will
counteract the tensile stress caused by a crack and
help to contain its propagation.
EDGE AND SURFACE CONDITIONS THAT
INFLUENCE PART PERFORMANCE
To understand how edge and surface quality can
impact part performance, some understanding of
how part surfaces developed from common machin-
ing, grinding, and other methods can negatively
influence part function over time. A number of fac-
tors are involved:
Positive vs. negative surface skewness: The
skew of surface profile symmetry can be an important
surface attribute. Surfaces are typically characterized
as being either negatively or positively skewed. This
surface characteristic is referred to as Rsk (Rsk–skew-
ness–the measure of surface symmetry about the mean
line of a profilometer graph). Unfinished parts usually
display a heavy concentration of surface peaks above
this mean line (a positive skew).
It is axiomatic that almost all surfaces produced
by common machining and fabrication methods are
positively skewed. These positively skewed surfaces
have an undesirable effect on the bearing ratio of
surfaces, negatively impacting the performance of
parts involved in applications where there is sub-
stantial surface-to-surface contact. Specialized high-
energy finishing procedures can truncate these sur-
face profile peaks and achieve negatively skewed
surfaces that are plateaued, presenting a much
higher surface bearing contact area. Anecdotal evi-
dence confirms that surface finishing procedures

5 Metal Finishing
tailored to develop specific
surface conditions with this
in mind can have a dramatic
impact on part life. In one
example, the life of tooling
used in aluminum can
stamping operations was
extended 1,000% or more by
improved surface textures
produced by mechanical sur-
face treatment.
Directionalized vs. ran-
dom (isotropic) surface
texture patterns: Somewhat
related to surface texture
skewness in importance is the
directional nature of surface
textures developed by typical
machining and grinding
methods. These machined
surfaces are characterized by
tool marks or grinding pat-
terns that are aligned and
directional in nature. It has
been established that tool or
part life and performance can
be substantially enhanced if
these types of surface tex-
tures can be altered into one
that is more random in
nature. Post-machining
processes that utilize free or
loose abrasive materials in a
high-energy context can alter the
machined surface texture sub-
stantially, not only reducing sur-
face peaks, but generating a sur-
face in which the positioning of
the peaks has been altered appre-
ciably. These “isotropic” surface
effects have been demonstrated to
improve part wear and fracture
resistance, bearing ratio and
improve fatigue resistance.
Residual tensile stress vs.
residual compressive stress.
Many machining and grinding
processes tend to develop resid-
ual tensile stresses in the surface
area of parts. These residual ten-
sile stresses make parts suscepti-
ble to premature fracture and
failure when repeatedly stressed.
Certain high-energy mass finish-
ing processes can be implement-
ed to modify this surface stress
condition, and replace it with
uniform residual compressive
stresses. Although, there are
many mechanical surface treat-
ments that will improve edge and
surface finish quality. A number
of processes are now specified
specifically because of their repu-
tation as performance-enhancing
processes, some of these are dis-
cussed below.
Abrasive flow machining
(AFM) is a process that, under
pressure, extrudes a semisolid
abrasive media that conforms to
the shape of the surface or pas-
sage that is being processed.
Polishing, deburring, and edge
radiusing are accomplished any-
where that the media can be
forced to flow. The abrasive flow
polished surface has no smeared
metal, and the radii generated
on any 90 degree edges are true
radii. The elimination of stress
risers, damaged metal layers,
and the generation of round
edges are used to help extend
component life.
Rotating parts can especially
benefit from the AFM process.
Fans, blisks, blades, disks, and
spacers can all benefit from this
surface and edge conditioning.
Highly polished surfaces also
tend to pick up less coke and car-
bon. This is especially important
on fuel systems components.
Blades and vanes located in both
the cool and warm sections of the
Figure 8: The Turbo-finish
method, more commonly
used for process rotating air-
craft engine parts, not only
deburrs and produces edge
contour, but also develops
compressive stress equilibri-
um and isotropic surface val-
ues that can be critical to
part life in service. (Courtesy
Dr. Michael Massarsky,
Turbo-Finish Corporation.)
Figure 9: Large aircraft frame
parts can be deburred, simi-
lar machinery can also be
used with steel media to
produce important residual
compressive stress in aircraft
frame components, an
important consideration for
large titanium components
such as the one illustrated
here. (Photo courtesy of
Samuel R.Thompson.)

6 Metal Finishing
engine can also benefit from highly polished sur-
faces in less turbulent air flow across their surfaces.
The abrasive flow process imparts compressive
residual stress. Although it will never replace shot
peening, it is used to extend part life on components
that, by configuration, cannot be shot peened.
The process is used to enhance holes and slots
prior to eddy current inspection. Many components
that are being inspected as part of an engine over-
haul are hand polished (butterflied) prior to inspec-
tion. The hand process is inconsistent and time con-
suming. AFM can be managed so that only the coke
and carbon are removed, greatly optimizing the
inspection process. Small holes on fuel system com-
ponents and turbine blades and vanes can be flow
tuned to ±1%. By more efficiently tuning cooling air,
hot section components will last longer and require
less air. Fuel-delivery components benefit from more
uniformity in both spray shape and flow rate. AFM
is used as the final machining and sizing operation.
The AFM process can be used to control stock
removal to ±0.0001 of an inch.
CENTRIFUGAL BARREL FINISHING
Centrifugal barrel finishing (CBF) is a high-energy
finishing method (see Figure 4) that has come into
widespread acceptance in the last 25 to 30 years.
Although not nearly as universal in application as
vibratory finishing, many important CBF applica-
tions have been developed in the last few decades.
These kinds of processes are utilized widely within
the aerospace and aircraft engine industries
because of their ability to produce high-quality
isotropic surface finishes rapidly on parts, such as
turbine blades and vane segments and developing
useful compressive stress values simultaneously.
Two or four barrels are mounted at the periphery of
a large turret. Each barrel is loaded with media,
parts, and water to approximately 50% to 90% full.
During operation, rotation of the large turret creates
a centrifugal force on the media and parts inside each
barrel. This force compacts the load into a tight mass,
causing the media and parts to slide against each
other, removing burrs and creating superior finishes.
This action also reduces the cycle time needed to com-
plete the finishing of the parts by up to a factor of 30
over conventional vibratory and barrel equipment.
Turbo-finish and performance issues: This
technology has been demonstrated
to successfully impart compressive
stresses into critical areas of rotat-
ing parts in a fashion that is
unique. The method is also capable
of producing surface conditions at
these critical edge areas that contribute to increased
service life and functionality of parts that are severe-
ly stressed in service. Among these are: (1) the cre-
ation of isotropic surfaces; (2) the replacement of pos-
itively skewed surface profiles with negative or
neutral skews; and (3) the development of an overall
stress equilibrium in parts with a complex feature set.
As previously mentioned, all common machining
and manual finishing methods produce uneven
stress hot-spots in machined parts. This occurs
because of the rapid rise and fall of temperature on
metal surfaces at the tool or wheel point of contact.
TAM not only produces beneficial compressive
stresses, but also in many cases, where all surfaces
and features are effected identically and simultane-
ously, can promote a stress equilibrium or uniformi-
ty throughout the entire part. Thus, TAM could be
looked at as a corrective after process for critical
parts that suffer from these machining-related sur-
face integrity issues.
The synergy involved in developing these kinds of
effects can add a potential value to service life, per-
formance, and functionality of parts that far exceeds
the value of the improvements to fit, function, and
aesthetics commonly associated with other mechan-
ical or mass finishing processes. Unlike single-point-
of-contact machining technologies, the technology is
relatively simple to control once process parameters
for a given part have been developed and, thus, has
the attributes of reliability and repeatability of sim-
pler mechanical (vs. digital feedback) technologies.
However, it accomplishes uniform results on very
complex parts that often cannot be achieved reliably
by other much more complex processes.
The technology involves developing a fluidized bed
of media in which the part to be processed is par-
tially immersed while being rotated. A wide variety
of differing results may be achieved by varying the
process parameters (media, process time, rotational
speed, etc.). Process results can be closely controlled
and are programmable, and are totally repeatable,
providing unequaled process quality control. The
process is dry, and involves no chemicals or environ-
mentally unfriendly materials.
VIBRATORY FINISHING LARGE AEROSPACE
COMPONENTS
Vibratory equipment can be designed to accommodate
Figure 10: Metallic media, such as the steel media shapes
illustrated here, have long been known to develop com-
pressive stress in barrel and vibratory finishing opera-
tions while burnishing, and cleaning part surfaces. This
capability is now being used in larger sized equipment to
strengthen large airframe components. Photo courtesy
of Abbott Ball Co.

7 Metal Finishing
aircraft components of extraordinary size. Large com-
ponents, such as aircraft engine cases and airframes,
can be finished with this method, not only cutting the
extensive costs related to manual deburring but
improving the uniformity and quality of edge and sur-
face finish quality. Additionally, these processes can
develop not only useful compressive stress but pro-
vide something very much like a stress equilibrium
enhancement throughout the part, as all part features
can be processed identically. Modified methods origi-
nally developed in the former Soviet Union with
metallic media can also be used to intensify this
effect, and has even been used to restore useful serv-
ice life to stressed or strained parts in overhaul cycles.
SUMMARY
Many parts that are subject to fatigue, fracture, or
wear can gain substantial improvements in life and
performance from alterations to their overall sur-
face texture. Improvements in overall smoothness,
load bearing ratio, surface profile skewness and
isotropicity can, in many instances, improve life and
performance and cut operational costs.
REFERENCES
Gillespie, LaRoux, “Mass Finishing Handbook,” Society of
Manufacturing Engineers, (New York, Industrial
Press) p. 61; 2007.
Gillespie, LaRoux, “Compiled Problems Caused by Burrs
and Sharp Edges,” (Spokane, Wash: Society of
Manufacturing Engineers, Deburring, Edge-Finish
and Surface Conditioning Technical Group, Spokane),
Newsletter, Vol 2, No. I, January 8, 2006, [Davidson,
D.A., ed.]; 2006.
Davidson, D.A., “Mass Finishing Processes,” 2005 Metal
Finishing Guidebook and Directory, 103(6A):78–89; 2005.
Massarsky, M. L., Davidson, D. A., “Turbo-Abrasive
Machining and Turbo-Polishing in the Continuous
Flow Manufacturing Environment”, SME Technical
Paper MR99-264, Conference Proceeding: 3rd
International Machining and Grinding Conference,
Cincinnati, Oct 4–7, 1999, Dearborn, Mich.: Society of
Manufacturing Engineers, 1999.
Gane, David H., Rumyantsev, H.T., Diep, Bakow, L.
“Evaluation of Vibrostrengthening for Fatigue
Enhancement of Titanium Structural Components on
Commercial Aircraft.” Ti-2003 Science and
Technology; Proceedings of the 10th World Conference
on Titanium, Hamburg Germany, 13–18 July 2003,
Edited by G. Lutejering and J Albrecht. Wiley-VCH,
Vol. 2. pp 1053–1058.
Massarsky, M. L., Davidson, D. A., “Turbo-Abrasive
Machining,” CODEF PROCEEDINGS, 7th International
Deburring Conference, Berkeley, Calif.: CODEF
[Consortium on Deburring and Edge Finishing],
University of California at Berkeley; June 2004.
ACKNOWLEDGEMENTS
The author wishes to acknowledge the technical
assistance of the following members of the newly
formed Society of Manufacturing Engineers DESC
Technical Group [Deburring, Edge-Finish, Surface
Conditioning]. Dr. Michael Massarsky, Turbo-Finish
Corporation; David H. Gane, Boeing; Edward F.
Rossman Ph. D., Boeing; Jack Clark, ZYGO
Corporation; LaRoux Gillespie, PE, CmfgE, Rodney
Grover, Society of Manufacturing Engineers.
For more information, please contact the author at
(e-mail) ddavidson@mgnh.dyndns.org. mf

Surface condition impacts part performancwe

More Related Content

What's hot (20)

Viewers also liked (18)

Similar to Surface condition impacts part performancwe (20)

More from Dave Davidson (20)

Recently uploaded (20)

Surface condition impacts part performancwe