Rolling and subsequent annealing are common processes to produce brass sheet. Cold rolling has attracted a lot of attention due to complicated deformation process that involves shear band and twinning. Debate remains on the level of deformation at which change in deformation mechanism occurs. Subsequent annealing process results in dynamic recrystallization, which is able to produce grain sizes and properties as required. Deteroriation of formability and ductility during cold rolling may be recovered during annealing. This research studied change of microstructure and mechanical properties of Cu-32%Zn (wt. %) brass during cold rolling and annealing processes. The Cu-32%Zn alloy was produced by gravity casting in a metal mold with the dimension of 110x110x6 mm3. The cast plate was homogenized at 800 oC for 5 h in an muffle furnace. The plate was then cold rolled with the level of deformation of 20, 40 and 70 % in multiple passes. Annealing of the cold rolled plate was conducted at 150, 200, 300, 400 and 500 oC for 30 minutes. The cooling of samples was performed in water. Characterization included Vickers hardness measurement and microstructural observation by using optical microscope. The results showed that slip was clearly observed at the level of deformation of 20 % together with few twinning. When the deformation was increased to 40 %, the twinning is major and some shear band started to form. Further increase of deformation to 70 %, the twinning was mostly replaced by shear band. The change in mode of deformation was followed by the increase in hardness of the materials. The annealing process after cold rolling resulted in recovery, recrystallization and grain growth. The higher the temperature of the annealing process, the speedier the recrystallization process that followed by grain growth and reduction in hardness.
|Number of pages||5|
|Journal||ARPN Journal of Engineering and Applied Sciences|
|Publication status||Published - 1 Jan 2016|
- Shear band
- Twin boundary