Stamping Process for Radiator Components

Stamping plays a very important role in the manufacturing process of radiator components. Below is a brief list of radiator components that require stamping process:

1. Modules: FIN sheets, base plates, hardware brackets, fasteners, etc.;
2. Heat pipes and vapor chambers (VC): Upper and lower cover blanks, copper meshes, press rivets, semi-finished product trimming, shaping, etc.

1 Basic Processes of Cold Stamping

According to the deformation characteristics of materials, cold stamping processes can be divided into two categories: separation processes and deformation processes.

1. Separation process: After the completion of this stamping process, the stress in the deformed part of the material exceeds the fracture stress of the material, resulting in fracture and separation of the material. Examples include punching, blanking, trimming and other processes.
2. Deformation process: After the completion of this stamping process, the stress in the deformed part of the material exceeds the yield stress σs of the material but does not reach the fracture stress σb, thereby causing plastic deformation of the material and changing the original shape and size of the material. Examples include bending, drawing, flanging, hole expanding and other processes.

2 Detailed Explanation of Blanking, Drawing, Bending and Other Forming Processes

According to the deformation characteristics, the cold stamping processes are shown in the figure below: These common cold stamping processes are almost all used in our heat dissipation products. Examples are as follows:

1. Blanking - VC blanks, VC semi-finished products, Fin, Clip, gaskets, Base, etc.
2. Drawing - VC blanks
3. Bending - FIN, Clip, Frame
4. Flanging - FIN
5. Bulging - VC rivets
6. Extrusion - VC rivets, heat pipe pressing
7. Necking - heat pipes (necking of hard pipes is actually cold extrusion)
8. Shaping - VC, heat pipes, etc.

As designers/manufacturing engineers of radiator components, we should have a basic understanding of the forming principles, design requirements, dimensional accuracy and adaptability of various stamping processes. For example, what is the minimum R-angle that can be achieved when designing the drawing cavity of the VC convex plate? How to avoid cracks at the R-angle at high temperatures caused by stress or local thinning? Another example is the mold design and feeding parameters for necking hard and soft heat pipes.

This involves professional stamping technology, mold technology and metal material forming technology. As an outsider, I won’t pretend to be an expert and will not elaborate further.

3 Classification and Characteristics of Cold Stamping Molds

According to the process nature, they can be divided into: trimming molds, blanking molds, bending molds, drawing molds, etc.;

According to the degree of process combination, they can be divided into: single-station stamping molds (single-process molds), compound molds, progressive molds (continuous molds).

The following table compares the characteristics, production efficiency and production cost of the three types of molds: single-station, compound and progressive molds:

4 How to Choose the Appropriate Mold Type?

For radiator components, there are generally two types of molds: single-station stamping molds or progressive molds. How to choose?

Combined with the above table, we can basically determine which mold to use from several aspects such as production capacity, efficiency and product complexity.

1. If multiple processes are required to stamp all features, a progressive mold should be adopted; otherwise, several sets of molds need to be opened for separate processes. For example: first punching, then drawing, then trimming and blanking; if a progressive mold is used, these three stamping stations can be completed sequentially in one set of progressive molds, which greatly saves stamping time and the time for manual handling, loading and unloading.
2. For mass production, progressive molds can be considered. Similarly, although a single-station stamping mold is cheaper per set, its production capacity may not keep up. In the end, it is necessary to open several sets of duplicate molds, which does not save costs but increases labor input.
3. For mass production but without production capacity pressure and small total demand, single-station stamping molds can be considered, which can reduce the mold investment cost. If the quantity is particularly small, a simple mold can also be flexibly used.

In addition, different scenarios and different molds correspond to different cold stamping equipment. Sometimes, it is also necessary to consider the actual condition of the equipment to choose the appropriate process/procedure.

5 Summary

Compared with other processes, the stamping process has short processing time, high efficiency and can achieve high precision. The precision of thick plate cuts and the bending precision of highly elastic metal parts may be slightly insufficient, but it can also meet the application in most cases, which is also closely related to the mold manufacturing level.

According to the precision requirements, there are also ordinary stamping and precision stamping. Precision stamping is relatively faster and more refined. If there are local parts with extremely high precision requirements, such as places with precision fitting and po

• Written by

  CoolingThermal Engineering Team

  CoolingThermal is an automation equipment manufacturer based in Kunshan, China, specializing in heat pipe and vapor chamber production equipment since 2017. Our engineering team designs, builds, and commissions complete production lines covering forming, degassing, welding, testing, and assembly processes. The technical content on this blog is written by the same team that develops the equipment — based on real production experience, not secondary research.