Aiming to decrease friction coefficient ( $\mu$ ) during the forming of magnesium alloy sheets, nine (9) tools with different hole geometries in their surface (flat, elliptical, and circular) were manufactured from steel Boehler W400 VMR (as known as DIN 1.2343). Tribological investigations were accomplished on a strip drawing machine at 288 °C without lubricants. When compared with a standard tool (surface flat), on average, tools with circular geometries in their surface showed the smallest friction coefficient, while tools with elliptical geometries shown higher. The friction coefficient also was confronted with the ratio between area occupied by holes in the surface of the tool and the total tool surface (i.e., factor f (%)), hole diameter (Ø), and the distance between circle centers (d(c,c)). Principal Component Analysis (PCA) complemented the experimental approach. In summary, both approaches (experimental and theoretical) indicated that the manufactured tool with circular geometries on its surface presented lower friction coefficient values on the forming processes of the magnesium AZ31 sheets.

In recent decades,the forming area advanced both in terms of material used as well as in flexibilityand process cost reduction. New processes are been studied, including theIncremental Sheet Forming – ISF. The ISF is a process characterized by theproduction of small batches of parts, rapid prototyping, and manufacturingflexibility with reduced operational cost. This study aims to compare thecomputer simulation with real experiments from ISF. The results of strain pathsof the three main strains simulated were consistent with the experimentalmanufacture of a symmetrical sample.

The conventional sheet metal forming processes, such as deep drawing and stretch forming, are used to produce large batches of parts, however they incur in higher initial manufacturing costs attributed to the use of a large amount of tooling. The application of conventional and incremental forming processes combined in the same metal sheet is called hybrid forming. This hybrid process is enacted by pre-forming the sheet through the stretch forming process followed by the final manufacture using the incremental process. The objective of this work is to analyze the influence of the pre-strain imposed during the conventional process on the DC04 steel relative to the maximum strain obtained. A numerical simulation was used to define the parameters for the conventional process and to evaluate the experimental results. The higher major true strains are inversely proportional to the pre-strain in both experimental and simulated results.

Low-alloy steel drill bits are commonly used in the mining industry for boring holes into rocks. They are characterized by high hardenability and a good combination of mechanical properties, with minimal additions of alloying elements. As product quality improves, the market becomes more competitive. Significant growth in the use of engineering development tools has also occurred, leading to improved performance in rock drilling, oil and mineral exploration, and the search for gemstones. Due to the constant cyclical mechanical stresses applied, the expected life of drill bits is often reduced by fatigue or mechanical wear, indicating that the market consistently requires the availability of new drill bits. This work aimed to demonstrate the suitability of hot forging as a substitute for machining to manufacture the specific profile of the drill bit preform used in rock drilling. A mining-industry partner selected AISI 8640 steel, as it is widely used for drilling applications. Tests were performed with AISI 8640 as a modeling material, and the results from the forging process were used to evaluate the punch movement and consequent metal flow, as well as the filling of the part’s cavity within the forging dies. The results obtained using Elementary Plasticity Theory (EPT) allowed verification of the physical experiment with AISI 8640 steel forged parts. Following this evaluation, numerical modeling was performed and compared with the hot forging process. Formation of the hollow cavity $$\sigma_b$$ within the part and the head of the preform in the same step was assessed. As a result of this optimized process, the reduction in the initial height of the billet and the preform formation were analyzed, with the finishing of the drill bit contingent upon the machining process. This hot forging demonstrated improved material utilization compared to the machining process, highlighting the benefits of deformation through simulations.