الملخص الإنجليزي
The primary purpose of this work is to create a Finite Element Model and conduct an
experimental investigation of the evolution of the microstructure and mechanical properties of
the 70/30 Brass during production processes of brass cartridge cases in order to measure and
simulate the material behaviour during forming process. The investigated forming process,
which consists of a series of drawing, annealing and other finishing processes, is considered as
one of the most advanced technologies in mechanical engineering because it permits the
production of a large number of products in a short amount of time while maximizing the use
of raw materials. The starting materials in this study, in the form of 70/30 Brass drawn cups,
were sourced from two different suppliers. The evolution of microstructure and mechanical
properties of the material was studied through chemical and mechanical characterization at
different stages of processing. The drawing process which is the main forming process was
modelled geometrically and computationally using the commercial finite element method
(FEM) package ABAQUS. ABAQUS is well known for effective modelling of cold and hot
forming processes of metallic materials. The purpose of the numerical simulation was to
determine the deformation changes in the semi-product material after each drawing step, with
a focus on the changes in dimensions and regions with the highest amount of plastic
deformation. The FEM model was successfully able to predict the dimensional changes after
each drawing steps. Moreover, the predicted distribution of plastic deformation after the final
drawing step was consistent with the hardness variation along the wall of drawn cans. Another
important finding of this study was the effect of the composition, microstructure and
mechanical properties of the starting materials on the properties of the final products despite
the extensive and severe thermomechanical processing. Therefore, a comprehensive
characterization of the starting materials should be carried out to avoid failures and defects
during or post processing and to ensure that the final products meet the specifications.
