Working Pressure, Deformation Modes and Fracture in Open-Piercing of Cylindrical Disks Made of Compacted Sintered Aluminium Powder

An experimental investigation into the quasi-static open-piercing of sintered aluminium powder compacts made initially in the form of thin and thick disks was made, using four different shaped punches, i.e. solid circular, annular (circular ring-type), triangular, and square. Typical results of punch load with punch movement and progressive changes in shapes of the specimens were observed and the onset of fracture was noted in each case. Available theory for calculating the piercing force was applied in a few cases and the results were compared with the experiments. These and other observations on the mechanical and metallurgical aspects of the deformation are given and the results commented upon.