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

Small cross section to increase resistivity

No wheatstone bridge--- use multimeter

Calculate desired length for R >1

Cut and measure diameter and resistance

R L

A L RA

Cold work sample Measure dimensions and resistance

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

Average R Change =106% Average CW =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%

Average R Change = 44% Average CW=20%

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

Average R Change=50% Average CW=17%

• 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.