Instructor Dr Mahdi NorouziNovember 18, 2021AbstractThis lab experiment was done to reinforce the ideas of using cooling curves and a phase diagram for Pb-Sn alloys. It was also done to determine the alloy composition and microstructure of two unknown alloys of Pb-Sn. The alloys of the two given samples were sample A had a chemical composition of Pb-43 Wt. % Sn and sample D had a chemical composition of Pb-100 Wt. % Sn.Laboratory Module 14 Solidification of Pb-Sn AlloysbyAdam BrewSchool of Engineering Grand Valley State UniversityAbstract, Results, ConclusionsEGR 251- Material Science & Engineering LabSection 102Instructor Dr Mahdi NorouziNovember 18, 2021AbstractThis lab experiment was done to reinforce the ideas of using cooling curves and a phasediagram for Pb-Sn alloys. It was also done to determine the alloy composition andmicrostructure of two unknown alloys of Pb-Sn. The alloys of the two given samples weresample A had a chemical composition of Pb-43 Wt. % Sn and sample D had a chemicalcomposition of Pb-100 Wt. % Sn.Results The cooling curves for the two samples of Pb-Sn metal alloy studied can be seen in Figure 1.The cooling curves were constructed from the data of melting and solidifying the two samples ofthe Pb-Sn alloys. Then table 1 shows the data that can be taken from the cooling curves todetermine the chemical composition of the alloys using the phase diagram for the Pb-Sn alloysseen in the appendix. Then using the data from the cooling curves and the phase diagram for Pb-Sn the microstructure of the alloys can be drawn at different temperatures.Figure 1- Cooling curves0 1000 2000 3000 4000 5000 60000.050.0100.0150.0200.0250.0300.0350.0Cooling curves for unknown alloys of Pb-Sn Sample ASample Dtime (s)Temperature (°C)Table 1- Experimental ResultsNo. Results Alloy A Alloy D1 Liquidus Temperature, TL230. 8 °C 232 °C2 Eutectic Temerature, TE181.2 °C NA3 Solidus Temperature, TSNA 232 ° C4 Solidification Range of alloy ∆T= TL -TE230.8 – 181.248.5 °CNA5 Melt Superheat (i.e. Initial Melt temperature – TL)328.8 – 230.898 °C330.6 – 23298.66 Elapsed time at liquidus temperature, tl3970 32457 Elapsed time at eutectic (or solidus)temperature, te4603 36458 Local solidification time, ∆t = te – tl633 09Solidification rate, ∆ T∆t0.155 010 Composition of alloy Pb-43 Wt. % Sn Pb-100 Wt % Sn11 Type of alloy ( hypoeutectic, hypereutectic, or eutectic)Hypoeutectic NA12 Amount of eutectic phase in the alloy ateutectic temperature43.3 % 0 %13 Type of primary phase in the alloy ateutectic temperatureα Sn14 Amount of primary phase in the alloy ateutectic temperature56.7 % 0 %15 Total amount of the α-phase at roomtemperature58.9 % 0 %16 Total amount of the β-phase at roomtemperature41.1 %Figure 2- Microstructure drawings for 2 samples of Pb-Sn alloysConclusions- This lab reinforced the ideas of phase diagrams and cooling curves learned in the lecture part of EGR 250- Alloy A was found to have a chemical composition of Pb- 43 Wt.% Sn- The primary phase of alloy A at the eutectic temperature was alpha with 56.7 % alpha- At room temperature alloy A was 58.9 alpha and 41.4 % Beta- Alloy B was found to have a chemical composition of Pb-100 Wt.% Sn- The primary phase of alloy B at the eutectic temperature was pure Sn- At room temperature alloy B was 100% SnAppendix Phase Diagram for Pb-Sn