Why Does The Cold-pressing Needle Process Avoid The Heat Treatment Step?

In precision manufacturing, the crimp contact process, with its unique material forming method, typically avoids traditional heat treatment steps after processing. The core reason lies in its processing nature and the special characteristics of the material response.

The core of the crimp contact pin process is the intense plastic deformation of metal at room temperature. Under high pressure, the needle penetrates the workpiece, forcing the material's internal grain structure to extend, break, and highly oriented along the deformation direction. This dynamic process immediately triggers a significant work hardening effect. Dislocation density increases dramatically, and grain size is refined to submicron or even nanometer levels, significantly improving the material's strength and hardness. The effect is similar to conventional quenching strengthening, but the process occurs directly during the forming stage. Related data shows that cold plastic deformation can instantly increase material strength by 15%-30%, providing a material basis for replacing heat treatment.

The high-temperature phase transformation involved in heat treatment poses a potential threat to the contact socket crimp process. The dense hardened layer or specific residual compressive stress distribution formed on the surface is the guarantee of its functionality. Secondary heating, whether annealing, tempering, or quenching, may destroy this carefully constructed microstructure. Grain coarsening and stress release lead to decreased hardness and impaired surface uniformity, ultimately weakening the wear resistance, fatigue life, and dimensional stability of the indenter. Improper heat treatment can cause surface hardness fluctuations of crimp contact female by as much as ±5 HRC.

Avoiding heat treatment not only preserves the high performance of crimp contact male achieved through deformation but also streamlines the production process, reducing energy consumption and deformation risks. Omitting this step, while meeting performance specifications, optimizes both efficiency and quality. Continuously optimizing cold pressing process parameters, such as pressure control, feed rate, and die design, is a more efficient way to ensure consistent needle performance.