Laboratory Module 14 Solidification of Pb Sn Alloys by Adam Brew School of Engineering Grand Valley State University Abstract Results Conclusions EGR 251 Material Science Engineering Lab Section 102 Instructor Dr Mahdi Norouzi November 18 2021 This 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 Abstract 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 of the Pb Sn alloys Then table 1 shows the data that can be taken from the cooling curves to determine the chemical composition of the alloys using the phase diagram for the Pb Sn alloys seen 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 curves Cooling curves for unknown alloys of Pb Sn C e r u t a r e p m e T 350 0 300 0 250 0 200 0 150 0 100 0 50 0 0 0 0 Sample A Sample D 1000 2000 3000 4000 5000 6000 time s Table 1 Experimental Results No Results Solidification Range of alloy 230 8 181 2 328 8 230 8 330 6 232 Liquidus Temperature TL Eutectic Temerature TE Solidus Temperature TS T TL TE Melt Superheat i e Initial Melt temperature TL Elapsed time at liquidus temperature tl Elapsed time at eutectic or solidus temperature te Local solidification time t te tl Solidification rate T t Alloy A 230 8 C 181 2 C NA 48 5 C 98 C 3970 4603 633 0 155 Composition of alloy Pb 43 Wt Sn Pb 100 Wt Sn Type of alloy Hypoeutectic hypoeutectic hypereutectic or eutectic Amount of eutectic phase in the alloy at 43 3 Type of primary phase in the alloy at Amount of primary phase in the alloy at 56 7 Total amount of the phase at room 58 9 Total amount of the phase at room 41 1 eutectic temperature eutectic temperature eutectic temperature temperature temperature Alloy D 232 C 232 C NA NA 98 6 3245 3645 0 0 NA 0 Sn 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Figure 2 Microstructure drawings for 2 samples of Pb Sn alloys Conclusions This lab reinforced the ideas of phase diagrams and cooling curves learned in the 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 lecture part of EGR 250 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 Sn Appendix Phase Diagram for Pb Sn alloys