team members: zack reinman cristhyan alfaro travis robinson daniel gilardoni engineering 45 dec,...
TRANSCRIPT
Team Members:Zack Reinman
Cristhyan AlfaroTravis RobinsonDaniel Gilardoni
Engineering 45Dec, 2009
SRJC
Our primary goal was to study the relationship between the deformation of metals and there resistances
Our secondary goal was study how annealing the metals would affect the resistance
Cold working started earlier than 5000 BC
Current applications involve shaping and hardening
Cold working is still done Byora USA Corporation
Bellevue, WA 425-454-0708
StalcopThorntown, IN765-436-7926
oColdform, Inc.Terryville, CT860-582-5031
Cold rolling, drawing, deep drawing, & pressing
Takes place at room temperatures Grain shapes deform allowing for increase
in resistivity
http://www.the-warren.org/ALevelRevision/engineering/grainstructure.htm
•Apply Heat to metal •New Grains Grow•Resistance decreases
http://www.the-warren.org/ALevelRevision/engineering/grainstructure.htm
We wanted to cold work large sample and measure its resistance with a Wheatstone bridge
Did not have high enough quality materials to build the circuit.
http://en.wikipedia.org/wiki/Wheatstone_bridge
In order to use multimeter, we had to get a resistance that was in the range the multimeter can detect. To increase the resistance of the object we reduced its cross-sectional area, and increase its length. ( ),
Resistance
cross-sectional area
resistivity of material
r
r
lR
AR
l length
A
Things were a little tricky because we were going from round wire to a flat ribbon
%CW Ao A fAo
100 (do2
)2 Tf W f
(do2
)2100
Copper Conductivity (1/omh*m) Length (m) Area (m2)
Theoretical R (ohms)
Expermental R (ohms) % Error
Sample 1 6.00E+07 3.0 5.16892E-08 0.967319499 1.05 8.55%
Sample 2 6.00E+07 3.0 5.16892E-08 0.967319499 1.05 8.55%
Sample 3 6.00E+07 3.0 5.16892E-08 0.967319499 1.1 13.72%
Copper CW % CW Length (m)
Conductivity (1/omh*m) Area (m2)
Theoretical R (ohms)
Experimental R (ohms)
R Change Due to CW (ohms)
Sample 1 12.59 4.31 6.00E+07 4.5161E-08 1.5905 3.6 2.01
Sample 2 20.58 6.52 6.00E+07 4.1032E-08 2.6483 5.4 2.75
Sample 3 20.08 6.14 6.00E+07 4.1290E-08 2.4783 4.65 2.17
BrassConductivity (1/omh*m) Length (m) Area (m2)
Theoretical R (ohms)
Expermental R (ohms) % Error
Sample 1 1.60E+07 1 6.13116E-08 1.019 1.4 37.34%
Sample 2 1.60E+07 1 6.13116E-08 1.019 1.4 37.34%
Sample 3 1.60E+07 1 6.13116E-08 1.019 1.4 37.34%
Brass CW % CW
Conductivity (1/omh*m)
Length (m) Area (m2)
Theoretical R (ohms)
Expermental R (ohms)
R Change Due to CW (ohms)
Sample 1 18.12 1.60E+07 1.23 5.01773E-08 1.53 2.25 0.72
Sample 2 19.46 1.60E+07 1.235 4.93547E-08 1.56 2.25 0.69
Sample 3 23.72 1.60E+07 1.24 4.67418E-08 1.66 2.35 0.69
Average % R Change Due to about 20% CW=44%
Unknown Length (m) Area (m2) Recorded R (ohms)Experimental Conductivity
Sample 1 1 4.57303E-08 6.75 3.24E+06
Sample 2 1 4.57303E-08 6.85 3.19E+06
Sample 3 1 4.57303E-08 6.95 3.15E+06
Avg 3.19E+06
Guessed metal---Chromel Conductivity=1.3X106 (1/ohm*m)
Unknown % CW Length (m) Area (m2)Determined Conductivity
Theoretical R (ohms)
Expermental R (ohms)
R Change Due to CW (ohms)
Sample 1 17.72 1.44 5.38E-08 3.19E+06 8.38 13.15 4.77
Sample 2 15.74 1.39 5.29E-08 3.19E+06 8.23 12.25 4.02
Sample 3 17.08 1.41 4.92E-08 3.19E+06 8.97 12.75 3.78
• Find Annealing temperature for our three samples
• Determine the temperature we want to use• We decided on 450 degrees F
• We didn’t see any results so…
• Changed temperature to 650 degrees F
• Changed from metal to glass due surface area and heat capacity
Color Dimensions
We later found our annealing temperatures were too low…
Melting temp for: copper = 1983F Brass= 1710F
http://en.wikipedia.org/wiki/Work_hardening http://www.iqsdirectory.com http://www.keytometals.com http://www.m-hikari.com/atam/forth/alquranATAM1-4-2010.pdf http://www.6mmbr.com/annealing.html http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWS-
4N08MH6-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1124432364&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=1e79518e220bfa7b771916e670b0ea5b
http://www.springerlink.com http://www.the-warren.org/ALevelRevision/engineering/grainstructure.htm Malki, B., L. Peguet, and B. Baroux. "Influence of Cold Working on the Pitting Corrosion Resistance of Stainless Steels."Corrosion Science. Isbergues:Elsevier, April 2007. 1933-1948. "Materials Engineering; Study data from M. Gonzalez and colleagues
update understanding of materials engineering. " Journal Engineering
12 Aug. 2009: Sciences Module, ProQuest. Web. 3 Dec. 2009.