EXAM 2 – Practice

“An Aggie does not lie, cheat, or steal or tolerate those who do”10. Determine the ASTM grain size number for this sampleMicrostructure of palladium (X200)6.00 cm x 7.40 cm11. A diffusion couple is formed between a special stainless steel and nickel. A temperature of 2500 degreesCelsius is held there for 20 hours. The initial concentration of nickel in steel is 0.40 wt%, and the surfaceconcentration is 1.00 wt%. How long will it take for the steel to reach a nickel content of 0.60 wt% at adistance of 0.6 mm into the steel? [8 points]12. You want to harden titanium by diffusion of carbon. The concentration of carbon at 1 mm into the surface ofthe titanium slab is 0.25 kg/m 3 and at 3 mm the concentration is 0.68 kg/m 3 . The temperature of thecarburizing environment is 925 degrees Celsius, and the rate at which carbon is entering the 2 mm thickregion is 1.27x10 -9 kg/(m 2 s). What is the diffusion coefficient for this treatment?13. The stress-strain diagram corresponds toan aluminum alloy cylinder that isstressed in tension where the aluminumalloy cylinder has an elastic-plastictransition. Fill in the each square withone (only one) of the following:a. Plastic deformationb. Yieldingc. Neckingd. Elastic deformatione. Fracturef. Plastic behaviorg. Modulus of elasticityh. Proportional limit