Introduction to Closed Die Forging

Closed die forging, also known as impression die forging, is a metal forming process that involves shaping and transforming metal into a desired shape using compressive forces. It is one of the oldest and most widely used forging methods in the manufacturing industry. In closed die forging, the workpiece is placed between two dies that contain the desired shape and are brought together to deform the material.

Here's an introduction to the closed die forging process:

1. Preparation: The closed die forging process begins with the preparation of the raw material, typically a heated metal billet or ingot. The material is preheated to a specific temperature to enhance its plasticity and facilitate the deformation process.

2. Tooling Design: The dies used in closed die forging are precision-engineered to match the desired final shape of the forged component. The dies consist of an upper and a lower die, often referred to as the hammer and anvil. The dies are machined to create cavities that correspond to the shape of the desired part.

3. Heating: The preheated metal billet is placed in the lower die, and the dies are brought together to enclose the workpiece. The closed die setup retains the material within the cavity during the forging process.

4. Compression: The dies are subjected to a high compressive force, typically applied by a mechanical or hydraulic press, to shape the metal. The force causes the material to flow and fill the cavities of the dies, resulting in the desired shape of the forged part. The force is maintained for a specific duration to ensure proper deformation and consolidation of the metal.

5. Flash Formation: In closed die forging, excess material, known as flash, is often forced out of the die cavities during the compression stage. The flash serves as a seal to prevent material leakage and ensures that the desired shape is maintained.

6. Finishing Operations: After the compression stage, the excess flash material is trimmed off to obtain the final shape of the forged part. Additional secondary operations like machining, heat treatment, surface finishing, and inspection may be performed to achieve the desired specifications and quality.

Closed die forging offers several advantages, including:

• Enhanced strength and mechanical properties due to the grain structure refinement and directional flow of the material.
• Precise control over the shape, dimensions, and surface finish of the forged components.
• High production efficiency and repeatability, making it suitable for large-scale manufacturing.
• Superior material utilization as the process minimizes waste and allows for close nesting of parts.

Closed die forging is used to manufacture a wide range of components, including automotive parts, aerospace components, agricultural machinery, industrial equipment, and more. It is favored for its ability to produce parts with excellent structural integrity, high strength, and dimensional accuracy.