Abstract
The change of pressure acting on the plunger during die casting was recorded by a wire strain gage bound on the plunger surface and an electromagnetic oscillograph. The displacement vs time curve of the plunger was also recorded by the same oscillogragh. The following results were obtained. (1) The pressure vs time curve had several peaks and plateaus. The plateau appeared during the period of filling the cavity with molten metal, while the peak indicate the end of filling up. (2) The pressures of plateaus and peaks increased with increasing pressure of the accumulator, though not in proportional ratio. (3) The tendencies of these curves varied with the different types of dies shown in Fig. 1 and Fig. 2 of our first report. Die II showed smoother a d lower peaks and plateaus than that of die I. This perhaps explains the superior mechanical properties of the test piece cast in die II.
