Ultrasonic Needle Straightening or Forming:
Straightening operation usually consists in achieving the designed shape of a metallic component or structure (Here a thin sheet). This operation could be done using heavy load pressing machines. For finition tasks, or when a distorsion is observed after a machining or a chemical process, to achieve with precision the curvature of a part by compring it to the jig, most common tool is a simple peen hammer.
Using such a tool implies a long process time, and could cause musculo-skeleton diseases for the operators.
Ultrasonic Needle Straigthening technique is a proven and reliable alternative of the peen hammer, with less impact for the operator.
Efficient process control, quick and easy-to-use tooling make this new technique popular.
Forming operation consists in modifying the shape of a metallic sheet to progressively achieving a desired shape.
Following schematics describes the Ultrasonic Straightening or Forming process principle:
Needles guided inside the peening head acquire velocity on the vibrating sonotrode and shock the metal to treat. A compressive stress layer is created on the surface. The difference of stresses between the surface and the core of the metal sheet result in a sheet curvature modification. By peening on the appropriate areas, one could adjust the part shape to its objectives (jig).