Cu-Zn-Pb brasses are popular materials, from which numerous industrially and commercially used components are fabricated. These alloys are typically subjected to multiple-step processing-involving casting, extrusion, hot forming, and machining-which can introduce various defects to the final product. The present study focuses on the detailed characterization of the structure of a brass fitting-i.e., a pre-shaped medical gas valve, produced by hot die forging-and attempts to assess the factors beyond local cracking occurring during processing. The analyses involved characterization of plastic flow via optical microscopy, and investigations of the phenomena in the vicinity of the crack, for which we used scanning and transmission electron microscopy. Numerical simulation was implemented not only to characterize the plastic flow more in detail, but primarily to investigate the probability of the occurrence of cracking based on the presence of stress. Last, but not least, microhardness in specific locations of the fitting were examined. The results reveal that the cracking occurring in the location with the highest probability of the occurrence of defects was most likely induced by differences in the chemical composition; the location the crack in which developed exhibited local changes not only in chemical composition-which manifested as the presence of brittle precipitates-but also in beta phase depletion. Moreover, as a result of the presence of oxidic precipitates and the hard and brittle alpha phase, the vicinity of the crack exhibited an increase in microhardness, which contributed to local brittleness.

Institute of Physics of Materials Czech Academy of Sciences 61662 Brno Czech Republic

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Davis J.R., editor. ASM Specialty Handbook ® Copper and Copper Alloys. 1st ed. ASM International; Materials Park, OH, USA: 2001. [(accessed on 2 March 2021)]. Available online: www.asminternational.org.

Kocich R., Fiala J., Szurman I., Macháčková A., Mihola M. Twist-channel angular pressing: Effect of the strain path on grain refinement and mechanical properties of copper. J. Mater. Sci. 2011;46:7865–7876. doi: 10.1007/s10853-011-5768-1. DOI

Hlaváč L.M., Kocich R., Gembalová L., Jonšta P., Hlaváčová I.M. AWJ cutting of copper processed by ECAP. Int. J. Adv. Manuf. Technol. 2016;86:885–894. doi: 10.1007/s00170-015-8236-2. DOI

Hamidah I., Solehudin A., Hamdani A., Hasanah L., Khairurrijal K., Kurniawan T., Mamat R., Maryanti R., Nandiyanto A.B.D., Hammouti B. Corrosion of copper alloys in KOH, NaOH, NaCl, and HCl electrolyte solutions and its impact to the mechanical properties. Alex. Eng. J. 2021;60:2235–2243. doi: 10.1016/j.aej.2020.12.027. DOI

Kocich R., Kunčická L., Král P., Strunz P. Characterization of innovative rotary swaged Cu-Al clad composite wire conductors. Mater. Des. 2018;160:828–835. doi: 10.1016/j.matdes.2018.10.027. DOI

Minitsky A., Byba I., Minitska N., Radchuk S. A study of the structure and properties of material based on an iron-copper composite powder. East. Eur. J. Enterp. Technol. 2019;2:44–50. doi: 10.15587/1729-4061.2019.164017. DOI

Kunčická L., Kocich R. Deformation behaviour of Cu-Al clad composites produced by rotary swaging. IOP Conf. Ser. Mater. Sci. Eng. 2018;369:012029. doi: 10.1088/1757-899X/369/1/012029. DOI

Kocich R. Effects of twist channel angular pressing on structure and properties of bimetallic Al/Cu clad composites. Mater. Des. 2021;196:109255. doi: 10.1016/j.matdes.2020.109255. DOI

Kunčická L., Kocich R., Strunz P., Macháčková A. Texture and residual stress within rotary swaged Cu/Al clad composites. Mater. Lett. 2018;230:88–91. doi: 10.1016/j.matlet.2018.07.085. DOI

Luo J., Zhao S., Zhang C. Microstructure of aluminum/copper clad composite fabricated by casting-cold extrusion forming. J. Cent. South Univ. Technol. 2011;18:1013–1017. doi: 10.1007/s11771-011-0796-1. DOI

Hu T., Yu X. Lightning Performance of Copper-Mesh Clad Composite Panels: Test and Simulation. Coatings. 2019;9:727. doi: 10.3390/coatings9110727. DOI

Guo J., Wang H., Zhang C., Zhang Q., Yang H. MPPE/SEBS composites with low dielectric loss for high-frequency copper clad laminates applications. Polymers. 2020;12:1875. doi: 10.3390/polym12091875. PubMed DOI PMC

Sharififar M., Mousavi S.A.A.A. Tensile deformation and fracture behavior of CuZn5 brass alloy at high temperature. Mater. Sci. Eng. A. 2014;594:118–124. doi: 10.1016/j.msea.2013.11.051. DOI

Farbod M., Mohammadian A., Ranjbar K., Asl R.K. Effect of Sintering on the Properties of γ-Brass (Cu5Zn8) Nanoparticles Produced by the Electric Arc Discharge Method and the Thermal Conductivity of γ-Brass Oil-Based Nanofluid. Met. Mater. Trans. A Phys. Met. Mater. Sci. 2016;47:1409–1412. doi: 10.1007/s11661-015-3295-4. DOI

Newman R.C. A theory of secondary alloying effects on corrosion and stress-corrosion cracking. Corros. Sci. 1992;33:1653–1657. doi: 10.1016/0010-938X(92)90041-Z. DOI

Galai M., Ouassir J., Touhami M.E., Nassali H., Benqlilou H., Belhaj T., Berrami K., Mansouri I., Oauki B. α-Brass and (α + β) Brass Degradation Processes in Azrou Soil Medium Used in Plumbing Devices. J. Bio-Tribo-Corrosion. 2017;3:1–15. doi: 10.1007/s40735-017-0087-y. DOI

García P., Rivera S., Palacios M., Belzunce J. Comparative study of the parameters influencing the machinability of leaded brasses. Eng. Fail. Anal. 2010;17:771–776. doi: 10.1016/j.engfailanal.2009.08.012. DOI

Xiao Y.H., Guo C., Guo X.Y. Constitutive modeling of hot deformation behavior of H62 brass. Mater. Sci. Eng. A. 2011;528:6510–6518. doi: 10.1016/j.msea.2011.04.090. DOI

Suárez L., Rodriguez-Calvillo P., Cabrera J.M., Martínez-Romay A., Majuelos-Mallorquín D., Coma A. Hot working analysis of a CuZn40Pb2 brass on the monophasic (β) and intercritical (α+β) regions. Mater. Sci. Eng. A. 2015;627:42–50. doi: 10.1016/j.msea.2014.12.093. DOI

Zhu A.-Y., Chen J.-L., Li Z., Luo L.-Y., Lei Q., Zhang L., Zhang W. Hot deformation behavior of novel imitation-gold copper alloy. Trans. Nonferrous Met. Soc. China. 2013;23:1349–1355. doi: 10.1016/S1003-6326(13)62603-5. DOI

Mapelli C., Venturini R. Dependence of the mechanical properties of an α/β brass on the microstructural features induced by hot extrusion. Scr. Mater. 2006;54:1169–1173. doi: 10.1016/j.scriptamat.2005.11.039. DOI

El-Bahloul A., Samuel M., Fadhil A.A. Copper-Zinc-Lead Alloys, Common Defects Through Production Stages and Remedy Methods. Online J. Sci. Technol. 2015;5:17–22.

Pantazopoulos G., Vazdirvanidis A. Characterization of the Microstructural Aspects of Machinable Alpha-Beta Phase Brass -2013-Wiley Analytical Science, Athens, Greece. [(accessed on 30 April 2021)];2006 Available online: https://analyticalscience.wiley.com/do/10.1002/micro.457/full/ DOI

Toulfatzis A.I., Pantazopoulos G.A., Paipetis A.S. Fracture mechanics properties and failure mechanisms of environmental-friendly brass alloys under impact, cyclic and monotonic loading conditions. Eng. Fail. Anal. 2018;90:497–517. doi: 10.1016/j.engfailanal.2018.04.001. DOI

Matsumoto J., Anada H., Furui M. The effect of grain size and amount of β phase on the properties of back-torsion working in 60/40 Brass. Adv. Mater. Res. Trans. Tech. Publ. 2007;15:661–666. doi: 10.4028/www.scientific.net/amr.15-17.661. DOI

Pantazopoulos G. Leaded brass rods C 38500 for automatic machining operations: A technical report. J. Mater. Eng. Perform. 2002;11:402–407. doi: 10.1361/105994902770343926. DOI

Radhi H.N., Mohammed M.T., Aljassani A.M.H. Influence of ECAP processing on mechanical and wear properties of brass alloy. Mater. Today Proc. 2021;44:2399–2402. doi: 10.1016/j.matpr.2020.12.461. DOI

Kunčická L., Kocich R., Drápala J., Andreyachshenko V.A. FEM simulations and comparison of the ecap and ECAP-PBP influence on Ti6Al4V alloy’s deformation behaviour; Proceedings of the Metal 2013 22nd International Metallurgy Material Conference; Brno, Czech Republic. 15–17 May 2013; pp. 391–396.

Jamili A.M., Zarei-Hanzaki A., Abedi H.R., Mosayebi M., Kocich R., Kunčická L. Development of fresh and fully recrystallized microstructures through friction stir processing of a rare earth bearing magnesium alloy. Mater. Sci. Eng. A. 2019;775:138837. doi: 10.1016/j.msea.2019.138837. DOI

Kocich R., Kunčická L., Macháčková A. Twist Channel Multi-Angular Pressing (TCMAP) as a method for increasing the efficiency of SPD. IOP Conf. Ser. Mater. Sci. Eng. 2014;63:012006. doi: 10.1088/1757-899X/63/1/012006. DOI

Kunčická L., Kocich R., Král P., Pohludka M., Marek M. Effect of strain path on severely deformed aluminium. Mater. Lett. 2016;180:280–283. doi: 10.1016/j.matlet.2016.05.163. DOI

Naizabekov A.B., Andreyachshenko V.A., Kocich R. Study of deformation behavior, structure and mechanical properties of the AlSiMnFe alloy during ECAP-PBP. Micron. 2013;44:210–217. doi: 10.1016/j.micron.2012.06.011. PubMed DOI

Alateyah A.I., Ahmed M.M.Z., Zedan Y., El-Hafez H.A., Alawad M.O., El-Garaihy W.H. Experimental and Numerical Investigation of the ECAP Processed Copper: Microstructural Evolution, Crystallographic Texture and Hardness Homogeneity. Metals. 2021;11:607. doi: 10.3390/met11040607. DOI

Kocich R., Macháčková A., Kunčická L. Twist channel multi-angular pressing (TCMAP) as a new SPD process: Numerical and experimental study. Mater. Sci. Eng. A. 2014;612:445–455. doi: 10.1016/j.msea.2014.06.079. DOI

Kocich R., Kunčická L., Král P., Macháčková A. Sub-structure and mechanical properties of twist channel angular pressed aluminium. Mater. Charact. 2016;119:75–83. doi: 10.1016/j.matchar.2016.07.020. DOI

Wang Z., Chen J., Besnard C., Kunčická L., Kocich R., Korsunsky A.M. In situ neutron diffraction investigation of texture-dependent Shape Memory Effect in a near equiatomic NiTi alloy. Acta Mater. 2021;202:135–148. doi: 10.1016/j.actamat.2020.10.049. DOI

Kocich R. Design and optimization of induction heating for tungsten heavy alloy prior to rotary swaging. Int. J. Refract. Met. Hard Mater. 2020;93:105353. doi: 10.1016/j.ijrmhm.2020.105353. DOI

Kocich R., Greger M., Macháčková A. Finite element investigation of influence of selected factors on ECAP process; Proceedings of the Metal 2010 19th International Metallurgy Material Conference; Rožnov pod Radhoštěm, Czech Republic. 18–20 May 2010; pp. 166–171.

Kocich R., Kursa M., Macháčková A. FEA of Plastic Flow in AZ63 Alloy during ECAP Process. Acta Phys. Pol. A. 2012;122:581–587. doi: 10.12693/APhysPolA.122.581. DOI

Russell A., Lee K.L. Structure-Property Relations in Nonferrous Metals. 1st ed. John Wiley & Sons, Inc; Hoboken, NJ, USA: 2005.

Svoboda J., Kunčická L., Luptáková N., Weiser A., Dymáček P. Fundamental improvement of creep resistance of new-generation nano-oxide strengthened alloys via hot rotary swaging consolidation. Materials. 2020;13:5217. doi: 10.3390/ma13225217. PubMed DOI PMC

Kunčická L., Kocich R., Ryukhtin V., Cullen J.C.T., Lavery N.P. Study of structure of naturally aged aluminium after twist channel angular pressing. Mater. Charact. 2019;152:94–100. doi: 10.1016/j.matchar.2019.03.045. DOI

Zappino E., Zobeiry N., Petrolo M., Vaziri R., Carrera E., Poursartip A. Analysis of process-induced deformations and residual stresses in curved composite parts considering transverse shear stress and thickness stretching. Compos. Struct. 2020;241:112057. doi: 10.1016/j.compstruct.2020.112057. DOI

Kunčická L., Kocich R., Dvořák K., Macháčková A. Rotary swaged laminated Cu-Al composites: Effect of structure on residual stress and mechanical and electric properties. Mater. Sci. Eng. 2019;742:742–750. doi: 10.1016/j.msea.2018.11.026. DOI

Kunčická L., Macháčková A., Lavery N.P., Kocich R., Cullen J.C.T., Hlaváč L.M. Effect of thermomechanical processing via rotary swaging on properties and residual stress within tungsten heavy alloy. Int. J. Refract. Met. Hard Mater. 2020;87:1–15. doi: 10.1016/j.ijrmhm.2019.105120. DOI