Method for monitoring a process during metal die casting or thixotropic moulding

A method for process monitoring during diecasting or thixotropic moulding of aluminum and magnesium alloys in a diecasting or thixotropic moulding installation which contains a casting chamber, a casting piston and a mould with a mould cavity, the method comprising the steps of:

• measuring temporal development of moulding pressure p(t);
• determining time-related speed of the casting piston v(t);
• calculating energy E(t) supplied by the casting piston as a function of process time t, and calculating total energy Etot supplied by the casting piston during the diecasting or thixotropic moulding process based on development of the moulding pressure p(t) and the casting piston speed v(t), and using the total energy Etot as a parameter for monitoring the diecasting or thixotropic moulding process, the step of calculating including calculating the energy E(t) supplied by the piston as a function of the process time t according to an integral function E ⁡ ( t ) = A · ∫ t 0 t ⁢ p ⁡ ( t ) · v ⁡ ( t ) ⁢ ⅆ t
• and calculating the total energy Etot supplied by the casting piston during the diecasting or thixotropic moulding process with an integral function E tot = A · ∫ t 0 t 4 ⁢ p ⁡ ( t ) · v ⁡ ( t ) ⁢ ⅆ t
• where A designates an area of the casting piston facing the diecasting or thixotropic moulding material, t0 designates a starting time t=0 of the diecasting or thixotropic moulding process and t4 designates a time at which the casting piston assumes speed v(t)=0 for a first time after t0.