Characteristics of graphite electrode discharge parameters

Update:01-11-2019
Summary:

(1) Peak current (IP) Features: The larger the peak cur […]

(1) Peak current (IP)

Features: The larger the peak current, the smaller the electrode loss and the larger the surface roughness. Under certain conditions, the processing speed is faster.

When the peak current > 12 A, the electrode loss reaches a minimum value;

When the peak current > 32 A, the machining starts to become unstable.

Selection criteria:

According to the current density:

Current Density -- The current value that can be withstood per unit area of ​​the electrode is called the current density of the electrode.

The experiment yields: Copper electrode: 6-8 A/cm2 Graphite electrode: 5-7 A/cm2

(2) Pulse width (ON)

Definition: The pulse width is the duration of the voltage pulse applied across the discharge gap between the electrode and the workpiece.

Features: The larger the pulse width, the smaller the electrode loss and the larger the surface roughness. Under certain current conditions, the processing speed is faster.

When the peak current is <12 A, the processing speed increases as the pulse width increases.

When the peak current is >16 A, the processing speed decreases with the increase of pulse width.

Experiments show that the loss value of graphite electrode can be reduced to less than 1% when the pulse width is >150 μs, achieving low loss processing target, but not exceeding 420 μs.