What Are the Requirements When Wire Cutting?

(1) the choice of suitable mold material line. Cutting process is generally carried out after the hardening of the blank: such as the use of T8A, T10A and other carbon, tool steel due to the difficulty of hardening through the hardened layer is shallow, after the use of resharpening may be worn off the hardened layer and a significant drop in hardness. In order to improve the service life of wire cutting tooling and processing accuracy, should be selected with good hardenability of alloy tool steel or carbide to manufacture these materials, from the surface to the center of the hardness is not significantly reduced.

(2) Reduce the surface roughness. The surface roughness of the mold cavity has a greater impact on the quality of plastic parts, in cutting and processing should be thought of ways to reduce the surface roughness. To this end, measures should be taken such as electrode wire tensioning should not be tight enough at any time; feed speed should be adjusted appropriately to avoid fluctuations in speed; mechanical transmission gap is too large is also easy to make the electrode wire shaking to increase the roughness of this to adjust the mechanical transmission part of the tightness in a timely manner; correct choice of electrical parameters to avoid a single pulse is too large. In addition, the electrode wire walking speed is too fast or jitter will also affect the surface roughness of the parts. They are not good for quality improvement.

(3) Choose a better wire cutting fluid (water-based working fluid). Wire cutting fluid plays a very critical role for wire cutting, so choose a good working fluid can improve the cutting efficiency surface finish and improve the stability of cutting.

(4) Reduce residual stress. In processing with wire cutting will cut off large pieces of metal, so that the relative equilibrium of the internal residual stresses in the material is disrupted, the stress will be redistributed. Residual stress in the material is sometimes more serious than the machine precision and other factors on the processing accuracy, can make the deformation to a macroscopic visible degree, even in the cutting process the material will break. In order to reduce the deformation caused by residual stresses, measures should be taken: the correct choice of heat treatment specifications; workpiece profile should be 8-100mm from the edge of the blank in the wire cutting before the aging process can be carried out.

Pre-machining before quenching to remove most of the residual; wire cutting using the second cutting method, the first rough cut type hole to achieve a new balance of stress and then fine cutting type hole; choose the correct cutting order, etc. Cross-cutting shears the above measures to reduce the residual stress in the material is of great benefit.

(5) improve the accuracy of mechanical transmission. Mechanical transmission accuracy has a great impact on processing accuracy. The displacement accuracy of the table and the accuracy of the movement of the electrode wire are directly affected by the processing accuracy. As the movement of the table is driven by a number of transmission vice such as gear vice, screw and nut vice, their transmission accuracy directly affects the machining accuracy. The movement accuracy of the electrode wire is affected by the rotation accuracy of the guide wheel, the uneven wear of the guide wheel and the slackness of the electrode wire. It can be seen that the mechanical transmission accuracy is not high on the processing quality has a greater impact.