Discussion on the Process Method of Metal Additive Manufacturing Technology

Nov 02, 2022

Additive Manufacturing (AM), commonly known as 3D printing, integrates computer aided design, material processing and forming technology, and is based on digital model files. Through software and numerical control system, special metal materials, non-metallic materials, and medical biological materials are stacked layer by layer according to extrusion, sintering, melting, photo curing, spraying and other methods to manufacture the manufacturing technology of physical articles. Different from the traditional processing mode of removing, cutting and assembling raw materials, it is a manufacturing method of "bottom-up" accumulation of materials from scratch. This makes it possible to manufacture complex structural parts which were constrained by traditional manufacturing methods and could not be realized in the past.

Additive manufacturing technology refers to a scientific and technological system that directly manufactures parts based on discrete stacking principle and driven by 3D data of parts. Based on different classification principles and understanding methods, additive manufacturing technology also has a variety of terms such as rapid prototyping, rapid prototyping, rapid manufacturing, 3D printing, etc. Its connotation is still deepening and its extension is also expanding. The "additive manufacturing" here has the same meaning as "rapid prototyping" and "rapid manufacturing".

At present, the relatively mature metal additive manufacturing technologies mainly include selective laser melting, laser melting deposition, electron beam melting, etc. Each process method has a relatively mature product supply market. Now, the three processes are briefly introduced by Qinhuangdao Zhugnwei Precision Editor:

1. Selective laser melting

The selective laser melting (SLM) process is that the 3D model of the workpiece is first layered, and then the scanning system is used to control the laser beam to irradiate the materials in the area to be shaped, so as to selectively melt the metal powder. After scanning each slice, the powder feeding system completely covers the formed area with new powder, and repeats these two actions continuously until scanning of all slices is completed, and finally the workpiece is formed layer by layer.

2. Laser melting deposition

Laser melt deposition (LMD) is also called laser direct manufacturing. Generally, high power laser is used, and the feeding mode is mostly synchronous powder feeding. Direct cascade deposition is its biggest technical feature. Compared with the traditional manufacturing process, this method has high flexibility, short process, and can significantly reduce the cost and time of finished products. It has great potential in the preparation of small batch and high-value metal parts.

3. Electron beam melting

Electron beam melting (EBM) is a process that uses electron beam to melt metal powder in high vacuum. Vacuum conditions and electron beam are the main differences between EBM and LMD and SLM. The parts manufactured by EBM technology have good compactness and high strength.

For more information about metal powder metallurgy, please consult Qinhuangdao Zhugnwei Precision.