Simultaneous Achievement of High Strength and Superior Ductility in an As-Rolled Cu-30Zn Brass.

Strength and ductility are the two most essential properties for copper alloys which are commonly used as structural materials. However, these properties are often mutually exclusive and seldom improved simultaneously in the samples fabricated through plastic deformation. For example, room temperature rolling (RTR) samples with a large deformation amount usually exhibit high strength but poor ductility. The present study provides an effective strategy for obtaining satisfactory mechanical properties in a Cu-30Zn brass. Compared with RTR sample with a large deformation amount (90%), a desired and outstanding combination of high strength and superior ductility can be achieved in a low deformation (70%) sample fabricated through ultra-low temperature rolling (UTR). The average tensile strength of 90% deformation RTR sample is 641.7 MPa, whereas that of 70% deformation UTR sample is 695.4 MPa. The average elongation of the 90% deformation RTR sample is only 3.7%. By contrast, the average elongation of 70% deformation UTR sample is 7.2%. In the meantime, the average yield strength of 70% deformation UTR sample is higher than that of 90% deformation RTR sample, which are 598.2 and 561.7 MPa, respectively. Large proportions of ultrafine grains and nanometer-scale deformation twins are responsible for the excellent mechanical properties of 70% deformation UTR sample. This effective method is vital for industry production to simultaneously obtain high strength and superior ductility in Cu-30Zn brass and may be also suitable for other copper alloys. [ABSTRACT FROM AUTHOR]