Electromagnetically-induced three-dimensional heating system for selective laser melting

Abstract

The invention discloses an electromagnetically-induced three-dimensional heating system for selective laser melting. The electromagnetically-induced three-dimensional heating system comprises a forming chamber, wherein a laser transmitter is arranged at the top of the forming chamber, a forming working platform is arranged at the bottom of the forming chamber, the forming working platform is cooperated with an inner body of a forming cylinder, a coil is arranged between the inner body of the forming cylinder and an outer body of the forming cylinder, the forming working platform is arranged in the coil, the coil is connected with an electromagnetic induction heating control cabinet, and the electromagnetic induction heating control cabinet is connected with a central controller; a graphite block is arranged between the inner body of the forming cylinder and the coil, a temperature sensor used for monitoring a temperature of the graphite block in real time is installed on the graphite block, and the temperature sensor is connected with the central controller; and an infrared thermometer used for monitoring temperatures of the machined parts in real time is installed in the forming chamber, and the infrared thermometer is connected with the central controller. The electromagnetically-induced three-dimensional heating system disclosed by the invention is used for uniformly heating the machined parts and a machining planar area, thus reducing the interlayer temperature gradients of cooling solidification and machining of an SLM metal molten pool, and reducing residual stresses in the metal parts; and online annealing can be realized.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing, and in particular relates to a three-dimensional heating system for laser selective melting electromagnetic induction. Background technique [0002] Selective laser melting (SLM) is one of the research hotspots in the field of additive manufacturing technology, especially in the direct forming of metal parts, which has great research and application value. In recent years, the quality and efficiency of SLM metal forming have continued to improve However, the existence of residual stress in SLM metal forming parts is still a problem. [0003] In laser selective melting metal forming, due to the extremely high laser energy density, the metal powder has experienced a process of rapid heating, melting and sudden cooling and solidification during processing. The data shows that the cooling rate of the molten metal pool can reach 10 5 K / s, this extremely high cooling rate is the main fa...

AI Technical Summary

Problems solved by technology

However, there are still some problems that have not been solved. For example, when preheating the powder, due to the poor thermal conductivity of the powder, it is easy to cause a large temperature difference of the powder, and after the powder passes through the powder spreading process, the heat loss of the powder is large, so the powder preheating effect is poor. The utilization rate is low; in the process of preheating (heating) the forming platform, the temperature in the SLM processing area is relatively uniform in the initial stage of processing, but as the height of the part becomes higher and higher, the forming platform decreases, and the processing plane and the heating device The distance between The farther the distance, the worse the heating effect of the processing plane, and the larger the temperature gradient; in the process of electromagnetic induction heating, due to the skin effect, it is easy to cause problems such as large temperature gradients of the processing platform and parts

Images