A comparative study on the machining performance of eco-friendly low lead and lead-free brass alloys in replacement for leaded ones

Year 2025, Volume: 43 Issue: 1, 241 - 249, 28.02.2025

Nima Zoghipour Emre Taşcioğlu Ali Özkan Keskin Yusuf Kaynak

Abstract

The use of brass alloys in pipelines and other fluid-carrying systems is widely recognized. The rolled or extruded bars are often machined to produce the manufactured products from these materials. When incredible machinability is required, leaded brasses are frequently employed. Leaded brass usage is prohibited, nevertheless, in systems that deal with environmental and human health hazards. In this study, three types of available brasses in EUA7038 (Brass for European Potable Water Applications List) leaded (CW617N), low-leaded (CW511L) and lead-free (CW724R) brasses haves been taken into consideration in terms of machinability; cutting forces, entry and exit burr height, subsurface microhardness, and microstructures. Experi-ments have been performed using several levels of feed and cutting speed on the mentioned materials during drilling tests. According to the obtained results, compared to leaded brass materials, low-leaded and lead-free brass materials showed more subsurface deformation. CW511L displays a sharper amendment rate of the in both entry and exit burr height with an increase in feed compared to CW724R and CW617N. It is significant to note that the machin-ability values for CW511L, CW724R, and CW617N are 1.4, 1.8, and 1.95 times, respectively.

Keywords

Brass, Lead, Machining, Surface Integrity, Twinning

References

• REFERENCES
• [1] Vilarinho C, Davim JP, Soares D, Castro F, Barbosa J. Influence of the chemical composition on the machinability of brasses. J Mater Process Technol 2005;170:441–447. [CrossRef]
• [2] Szyszkowski A. Les principaux laitons au plomb et leurs usages, Centre Belge d' Information du Cuivre. 53, Symposium, Les laitons, 1973.
• [3] Ragon R, Stucy M. Influence du plomb sur l'usinabilite' des alliages cuivreux pour robinetterie. Fonderie-Fondeur d' aujourd' hui 1973;170:8–15.
• [4] Saigal A, Rohatgi P. Machinability of cast lead free yellow brass containing graphite particles. AFS Trans 1996;104:225–228.
• [5] Whiting L, Newcombe P, Sahoo M. Casting characteristics of red brass containing bismuth and selenium. AFS Trans 1995;103:683–691.
• [6] Twarog D. Modified red brass with bismuth and selenium: research results. AFS Trans 1995;103:451–461.
• [7] L' usinage des alliages cuivreux. Fonderie-Fondeur d' aujourd' hui 1975;267:12–16.
• [8] French A. Improved free-machining leaded brass. J Inst Metals 1973;101:125–137.
• [9] Thomas P, Le J, Arnaud D. Influence des impuret' es sur les proprietes des laitons. Fonderie 1959;162:323–325.
• [10] Cooper Development Association. Brass for European Potable Water Application. Available at: https://www.copper.org/applications/rodbar/ pdf/A7038-brass-for-european-potable-waterapplications.pdf Accessed Jan 14, 2025.
• [11] Rohs Exemptions. Available at: https://rohs.exemptions.oeko.info/fileadmin/user_upload/RoHS_Pack_9/Exemption_6_c_/Exemption_6c__2015-10-mitsubishishindoh-rohs.pdf Accessed Jan 14, 2025.
• [12] Peters D. Bismuth Modified Cast Red Brasses to Meet U.S. Drinking Water Standards, Copper Development Association; 1995.
• [13] Davies D. Bismuth in copper and copper base alloys: a literature review. Technical Report, Copper Development Association, 1993.
• [14] Reddy VV, Krishna AV, Schultheiss F, Rosén B-G. Surface topography characterization of brass alloys: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P). Surf Topogr Metrol 2017;5:1–11.[CrossRef]
• [15] Toulfatzis AI, Pantazopoulos GA, David CN, Sagris DS, Paipetis AS. Machinability of eco-friendly leadfree brass alloys: Cutting-force and surface-roughness optimization J Metals 2018;8:250. [CrossRef]
• [16] Toulfatzis A, Pantazopoulos G, Paipetis A. Microstructure and properties of lead-free brasses using post-processing heat treatment cycles. Mater Sci Technol 2016;32:1771–1781. [CrossRef]
• [17] Aytekin K. Characterization of machinability in lead-free brass alloys. Degree Project In Materials Design and Engineering, Second Cycle, 30 Credits Stockholm, Sweden, 2018.
• [18] Tam PL, Schultheiss F, Sta˚hl J-E. Residual stress analysis of machined lead-free and lead-containing brasses. Mater Sci Technol 2016;32:1789–1793. [CrossRef]
• [19] Özbey S. Production of lead-free brass alloys, and the effect of some additive on machinability, mechanical and corrosion properties. Doctorial Thesis. Istanbul: Department of Metallurgical and Materials Engineering, Maramara University, 2020.
• [20] Schultheiss F, Johansson D, Linde M, Tam PL, Bushlya V, Zhou J, et al. Machinability of CuZn21Si3P brass. Mater Sci Technol 2016;32:1744–1750. [CrossRef]
• [21] Johansson J, Persson H, Ståhl J-E, Zhou J-M, Bushlya V, Schultheiss F. Machinability evaluation of lowlead brass alloys. Proced Manufact 2019;38:1723–1730. [CrossRef]
• [22] Nobel C, Klocke F, Lung D, Wolf S. Machinability enhancement of lead-free brass alloys. Proced CIRP 2014;14:95–100. [CrossRef]
• [23] Zoghipour N, Tascioglu E, Kaynak Y. Machinability of extruded and multi-directionally hot forged eco-friendly brass alloys. Can Metall Q 2023;63:1–12. [CrossRef]
• [24] Zoghipour N, Tascioglu E, Atay G, Kaynak, Y. Machining-induced surface integrity of holes drilled in lead-free brass alloy. Proced CIRP 2020;87:148–152. [CrossRef]
• [25] Kato H, Nakata S, Ikenaga N, Sugita H. Improvement of chip evacuation in drilling of lead-free brass using micro drill. Int J Automot Technol 2014;8:874–879. [CrossRef]
• [26] Fountas N, Koutsomichalis A, Kechagias JD, Vaxevanidis NM. Multi-response optimization of CuZn39Pb3 brass alloy turning by implementing Grey Wolf algorithm. Frattura ed Integrità Strutturale 2019;50:584–594. [CrossRef]
• [27] Sarbak. Alaşımlar. Available at: https://www.sarbak.com.tr/dokuman/alasimlar/en/ Accessed Jan 14, 2025.