Electrical discharge wire cutting (EDW) is a precision manufacturing technique that can cause deformation and stress in materials during the machining process. This deformation is primarily caused by thermal stress generated during cutting. The thermal stress produced during cutting can cause the material to deform in an undirected and unregulated manner, leading to uneven cutting feed and affecting cutting accuracy. Additionally, if a large area of a material is cut, the relative balance of residual stress within the material can be disrupted, causing significant deformation.
To reduce the deformation caused by electrical discharge wire cutting, the following measures can be taken:
Rough Machining or Stress Relief Cutting Before Cutting: By mechanically rough-machining the material before hardening to remove most of the excess and waste material, the stress generated during hardening can be reduced. For electrical discharge wire cutting of large die cavities, a two-step main cutting process can be used. First, perform the main cutting with an increased offset of 0.1-0.2mm on each side for the first main cut to release stress, and then use the standard offset for the second main cut.
Machining of the Wire-Threading Hole: Machining a wire-threading hole in the material and performing a closed contour machining can significantly reduce the deformation caused by electrical discharge wire cutting.
Optimizing the Machining Path: By optimizing the machining path, the imbalance of internal stress in the material can be reduced, thereby reducing deformation.
Reserving Machining Allowance: Reserve different machining allowances for different materials to fully release internal stress and deformation.
Heat Treatment and Rough Machining: Perform appropriate heat treatment and rough machining before processing to eliminate defects in material properties and blank shape, improving machining accuracy.
By implementing these measures, the deformation and stress caused by electrical discharge wire cutting can be controlled to a certain extent, thereby improving machining accuracy and product quality.
