Presentation on theme: "Team Members: Zack Reinman Cristhyan Alfaro Travis Robinson Daniel Gilardoni Engineering 45 Dec, 2009 SRJC."— Presentation transcript:
Team Members: Zack Reinman Cristhyan Alfaro Travis Robinson Daniel Gilardoni Engineering 45 Dec, 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 Byora USA Corporation Stalcop Thorntown, IN 765-436-7926 Stalcop o Coldform, Inc. Terryville, CT 860-582-5031 Coldform, Inc.
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.
Small cross section to increase resistivity No wheatstone bridge--- use multimeter
Calculate desired length for R >1 Cut and measure diameter and resistance
Cold work sample Measure dimensions and resistance
Things were a little tricky because we were going from round wire to a flat ribbon
Copper Conductivity (1/omh*m)Length (m)Area (m 2 ) Theoretical R (ohms) Expermental R (ohms)% Error Sample 16.00E+073.05.16892E-080.9673194991.058.55% Sample 26.00E+073.05.16892E-080.9673194991.058.55% Sample 36.00E+073.05.16892E-080.9673194991.113.72% Copper CW% CWLength (m) Conductivity (1/omh*m)Area (m 2 ) Theoretical R (ohms) Experimental R (ohms) R Change Due to CW (ohms) Sample 112.594.316.00E+074.5161E-081.59053.62.01 Sample 220.586.526.00E+074.1032E-082.64835.42.75 Sample 320.086.146.00E+074.1290E-082.47834.652.17
Brass Conductivity (1/omh*m)Length (m)Area (m 2 ) Theoretical R (ohms) Expermental R (ohms)% Error Sample 11.60E+0716.13116E-081.0191.437.34% Sample 21.60E+0716.13116E-081.0191.437.34% Sample 31.60E+0716.13116E-081.0191.437.34% Brass CW% CW Conductivity (1/omh*m) Length (m)Area (m 2 ) Theoretical R (ohms) Expermental R (ohms) R Change Due to CW (ohms) Sample 118.121.60E+071.235.01773E-081.532.250.72 Sample 219.461.60E+071.2354.93547E-081.562.250.69 Sample 323.721.60E+071.244.67418E-081.662.350.69 Average % R Change Due to about 20% CW=44%