The demand for more efficient manufacturing processes has been increasing in the last few years. The cold forging process is presented as a possible solution, because it allows the production of parts with a good surface finish and with good mechanical properties. Nevertheless, the cold forming sequence design is very empirical and it is based on the designer experience. The computational model...

The results from experimental research of deformation by upsetting and die forging of lead specimens wit controlled impact are presented. Laboratory setup for conducting the investigations, which uses cold rocket engine operated with compressed air, is described. The results show that when using controlled impact is achieving greater plastic deformation and consumes less impact energy than at o...

Accuracy is the key issue in the precision forging. Geometric and dimension errors are the two significant defects found in most of near net or net shape manufacturing process. It becomes more critical for complex part such as an AUV propeller blade. In this study, geometric error was quantified by comparing the blade profile obtained from nominal geometry of the blade and the profile construct...

In cold forging processes the tribological conditions are very important for process feasibility and tool lifetime. Since boundary and mixed lubrication conditions are predominant in cold forging processes, the appearing real contact area which is influenced significantly by the topography of tool and workpiece has a major impact on the friction conditions. Against the background of current tre...

Accuracy of the net-shape manufacturing such as forging becomes critical as the process depends on many factors. Defect will harm the assembly tend to affect the performance of the part. Therefore, it must be detected and minimized it as soon as the manufacturing begins. Small size and complexity of the part limits the defective part to be assessed. The paper presents an investigation on the de...

There are a wide range of physical defects which occur during metal forming processes. These defects, which may occur on the surface or be internal, are undesirable not only because of the surface appearance, but because they may adversely affect the strength, formability and other manufacturing characteristics of the material. Some physical defects in metal forming processes such as rolling an...

The paper reports on an investigation into the various aspects of closed die cold forging of polygonal powder preforms, which have been compacted and sintered from atomized powder. It is found that for certain dimensional ratios of the preform the die pressure is minimum. An attempt has been made for the determination of the die pressures developed for given geometries of the disc during the cl...