Microstructure and mechanical properties of bimetallic copper/brass laminates fabricated via accumulative press bonding

An accumulative press bonding (APB) process up to three cycles was used to fabricate copper/brass multi-layered composites. The resulting composites were characterized using scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), and energy-dispersive X-ray spectroscopy (EDS) techniques. Three cycles of the APB process yielded mean grain sizes of 3.1 and 1.5 mu m for the press-bonded copper and brass layers, respectively. A detailed EBSD study of the microstructure comprising the copper layer revealed a bimodal grain structure where a coarse-grained region was sandwiched between fine-grained areas. The adiabatic heat generated by the severe plastic deformation may have provided the conditions for grain growth in the coarse-grained part. The yield strength and ultimate tensile strength of the composite improved continually with strain reaching values of 401 and 523 MPa, respectively, after three cycles of the APB process. The values were about similar to 2.3 and 6.0 times higher than the corresponding values of initial pure copper material.

Automated summary

A multi-layered composite of copper/brass was fabricated using the APB process with up to three cycles, resulting in controlled grain sizes for the copper and brass layers. The microstructure of the copper layer exhibited a bimodal grain structure, while the mechanical properties of the composite continued to improve with each cycle of the APB process, reaching significantly higher values than the initial pure copper material.