PSI - Issue 65

A.V. Sulitsin et al. / Procedia Structural Integrity 65 (2024) 282–289 A.V. Sulitsin, , S.V. Brusnitsyn, D.O. Levin, D.A. Usov, V.K. Dubrovin / Structural Integrity Procedia 00 (2024) 000–000

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It can be seen that when a modifier is added in an amount of up to 0.05 wt. %, there is an increase in tensile strength and elongation. Obviously, this is due to a decrease in the grain size. It should be noted that with an increase in the amount of the introduced modifier by more than 0.05 wt. %, the strength characteristics change insignificantly, while the relative elongation decreases. This is probably due to the release of intermetallic phases containing nickel in the brass structure, which provide strengthening of the alloy. Moreover, with an increase in the quantity of added modifier, the Rockwell hardness HRB increases from 85 to 92. The results of experiments allowed us to conclude that it is an effective method of influencing the crystallizing melt, and also to establish the quantity of modifier 0.04...0.06 wt. % necessary to increase the level of mechanical properties. As part of the study, micro-X-ray spectral analysis of the alloy was carried out. The distribution of elements in the α-phase, (α+β')-phase and intermetallic compounds in the structure of ingots was studied. The results are presented in Fig. 5 and Table 2.

Fig. 5. The microstructure of the alloy 70Cu-13Zn-7Mn-5Al-2Fe-2Si-1Pb with the addition of Ni-Mg-Ce ligature: α-phase (1); (α+β')-phase (2); intermetallic (3).

Table 2. Chemical composition of phase of alloy 70Cu-13Zn-7Mn-5Al-2Fe-2Si-1Pb with addition of Ni-Mg-Ce ligature. Element Content of element α-phase (α+β')-phase Intermetallic ( wt. %) ( at. %) ( wt. %) ( at. %) ( wt. %) ( at. %) Mg 0.30 0.73 - - 0.39 0.72 Al 4.63 10.22 6.15 13.39 0.76 1.25 Si 0.31 0.65 - - 24.18 38.41 Mn 3.11 3.38 3.51 3.75 22.47 18.26 Fe 0.54 0.57 0.39 0.41 49.76 39.77 Ni 0.34 0.35 0.28 0.28 - - Cu 76.88 72.11 75.56 69.88 1.94 1.37 Zn 12.81 11.68 13.48 12.11 0.23 0.16 Pb 1.08 0.31 0.63 0.18 0.27 0.06 It was found that when adding the ligature in the amount of 0.05 wt.% in the alloy structure in the α- and (α+β')- phases, copper and zinc are present in significant quantities, and in the intermetallic compound – iron, silicon and manganese. The results of laboratory experiments showed that the use of the Ni-Mg-Ce ligature is justified and it is advisable to carry out industrial experiments with its use.