Special Edition: Supercooled, Superheated & Supersaturated

1. Special Edition: Supercooled, Superheated & Supersaturated Supercooled Water Superheated Water Supersaturated Water • Supercooled – “supercooled fiji water freezing”. Googling words • http://www.youtube.com/watch?v=lISK1YFcZBM • Why did the water freeze by tapping on the bottle? • Superheated – “superheated solution exploding” • http://www.youtube.com/watch?v=2FcwRYfUBLM • Why did the water explode in the microwave oven? • Supersaturated – “supersaturated salt solution crystallizing youtube” • http://www.youtube.com/watch?v=1y3bKIOkcmk Why did massive precipitation occur when a grain of sodium acetate was dropped? 1

2. Activity 3 - Phase Characterization – 40% Sn, A Hypoeutectic Alloy (150C) Given temp. & nom. comp what are: 1. Phases Present2. Each Phase Chemical Comp.3. Each Phase Weight Fraction Given: 1) Temp 2) Nominal comp % Sn - % Pb Get: 1) Phases Present 2) Phases Chem. comp. 3) Phases Frac. Given 1) 150C; 2) 40Sn-60Pb (2-phase region) nominal composition 2

3. Activity 2 - Stress Strain Curve Example CalculationDetermine the following quantities given below. Elastic modulus: E = _________ Yield Strength: YS 0.2%e = ________ Tensile Strength: TS = _________ Breaking Strength: BS = ________ Ductility % elongation %el = ________ Ductility % Reduct. Area: %RA = _______ x Afinal = 0.9 Aoriginal 3

4. D = 0.40 in o Cu Cold Work D = 0.35 in f Activity 2: Effect of Cold Work on YS, TS, & %el • Reduce a Cu rod 0.40 in (10.2 mm) dia. to 0.35 in (8.9 mm). • Determine YS, TS and ductility YS TS %el • YS = ________ • TS = ________ • Ductility %el = ___ YS 4