The reason why molybdenum wire breaks easily

1.Tension and wire speed

1) Increasing the tension of molybdenum wire can reduce the influence of wire vibration, thus improving the precision and cutting speed, and obviously reducing the broken wire. It is generally considered that the tension is suitable for 12-15n.

2) The increase of wire speed is conducive to the introduction of the working fluid into the discharge gap of the workpiece with large thickness by molybdenum wire, so as to ensure the elimination of the hot blood of the corrosion products and the stability of the discharge machining. However, if the wire speed is too high and the molybdenum wire shakes seriously, the stability of the processing will be destroyed, the processing accuracy and the surface roughness will become worse, and it is easy to break the wire. When the wire speed is too low, it is easy to break because of the large loss. Generally, it is better to be less than 10 m / s.

2.Broken wires related to guide wire structure

) The different axes of the inner and outer circles of the screw barrel will produce the unbalanced inertia, which is easy to produce the overlapped wires and lead to the broken wires during the operation.

2) The gap between the shaft and bearing of the screw barrel is often caused by wear, which is easy to cause the wire shaking and broken.

3) If the high-frequency power supply is not cut off during the reversing of the screw barrel, the molybdenum wire will burn due to the high temperature in a short time. Therefore, it is necessary to check whether the travel switch at the back end of the screw barrel fails (whether the relay controlling the high-frequency is damaged).

3.Broken wire in cutting process

When the molybdenum wire cut into the workpiece, due to the narrow cutting seam and the difficulty of emulsion penetration, the electrical erosion (carbon black and metal objects) in the cutting seam are not easy to be removed, which makes the processing conditions worse, and secondary and tertiary discharge processing occurs in the cutting seam, resulting in the widening of the cutting seam, the gap into the poor state, and the pulse forming arc discharge, resulting in the wire breakage.