How to reduce or eliminate defects during Selective Laser Melting?
Publish Time: 2024-10-21
As an advanced metal additive manufacturing technology, Selective Laser Melting not only brings many advantages, but also faces the challenge of defect generation. Here are some ways to reduce or eliminate defects during Selective Laser Melting.
First, optimizing process parameters is the key. Including laser power, scanning speed, scanning spacing, powder thickness, etc. Through a large number of experiments and simulations, the best combination of parameters is found to ensure that the metal powder can be fully melted and fused, and reduce the generation of defects such as unfused and holes. For example, appropriately reducing the scanning speed can increase the action time of the laser on the powder and improve the melting effect, but too low a speed may cause excessive melting and deformation.
Strict control of raw material quality is also very important. The particle size distribution, sphericity, purity, etc. of metal powder will affect the process and part quality of Selective Laser Melting. Selecting high-quality, uniform powder and avoiding particles containing impurities and irregular shapes can reduce the incidence of defects. At the same time, the powder is dried to prevent impurities such as moisture from causing defects such as pores during the melting process.
Improving equipment performance is also an effective way. Ensure the stability and accuracy of the laser system and ensure uniform energy distribution of the laser beam. A good powder spreading system can achieve a uniform powder layer and reduce defects caused by uneven powder spreading. In addition, use advanced monitoring technologies such as real-time temperature monitoring and optical monitoring to detect problems and make adjustments in time.
In terms of design, reasonable part structure design can reduce defects. Avoid overly complex shapes and sharp changes to reduce stress concentration and heat accumulation. Use appropriate support structures to prevent parts from deforming and collapsing during the manufacturing process.
Finally, post-processing processes can also help eliminate some defects. For example, heat treatment can improve the microstructure of parts, eliminate residual stress, and improve mechanical properties. Surface treatment can remove rough parts and tiny defects on the surface and improve the surface quality of parts.
In short, by optimizing process parameters, controlling raw material quality, improving equipment performance, rationally designing part structure, and adopting post-processing processes, the defects generated during Selective Laser Melting can be effectively reduced or eliminated, and the quality and reliability of parts can be improved.
