Self-disturbance laser additive manufacturing method

Abstract

The invention discloses a self-disturbance laser additive manufacturing method. The method comprises the following steps of: obtaining structural characteristics of a formed part; obtaining thermophysical parameters of a formed material; constructing a self-disturbance laser additive manufacturing system; designing self-disturbance parameters of a laser beam of the self-disturbance laser additive manufacturing system according to the structural characteristics and the thermophysical parameters; setting forming process parameters of the laser beam according to the structural characteristics and the thermophysical parameters; and manufacturing the formed part according to the self-disturbance parameters and the forming process parameters. According to the self-disturbance laser additive manufacturing method, one-dimensional linear scanning of the laser beam in the prior art is converted into periodic two-dimensional graphic disturbance, stirring of a liquid molten pool is realized under the condition of no additional physical field, the functions of homogenizing a microstructure, refining grains, inhibiting element burning loss, reducing metallurgical defects such as cracks and air holes, increasing the size of the molten pool and shortening the machining time are achieved, and the forming efficiency can be greatly improved while the part is guaranteed to have excellent comprehensive mechanical properties.

Description

technical field [0001] The invention belongs to the technical field of laser additive manufacturing, and in particular relates to a self-disturbance laser additive manufacturing method. Background technique [0002] Selective Laser Melting (SLM) is a potential additive manufacturing technology. It is based on the principle of layered manufacturing and layer-by-layer superposition. It uses a high-energy-density laser beam to perform point-by-point, Melting line by line and layer by layer can directly produce complex shape parts with good metallurgical bonding, excellent dimensional accuracy and surface quality in one step. So far, there have been many reports of successful cases of applying this technology to form titanium alloys, aluminum alloys, magnesium alloys, stainless steel, copper alloys and superalloys. The existing SLM technology realizes the rapid positioning and position switching of the laser beam by scanning the galvanometer, and its scanning strategy is "linea...

AI Technical Summary

Problems solved by technology

[0003] However, the SLM technology based on "linear scanning" has the following problems: First, because the interaction time between the high-speed "linear" scanning laser and the powder is only 10 -4 s-10 -5 s, the molten pool generated by the laser during the forming process is 10 -4 mm 3 Size-level micro-melt pool, laser power density up to 10 5 W / cm 2 -10 7 W / cm 2 , cooling rate up to 10 6 K / s-10 8 K / s, temperature gradient at 10 5 ℃ / mm level

However, the SLM forming process is carried out in a closed cavity, and the use of additional physical external fields leads to more complex production equipment and preparation processes, which greatly increases production costs; at the same time, it is difficult to achieve uniform vibration by applying physical external fields when preparing large precision and complex parts Stirring effect, so the above techniques cannot be applied to SLM forming

Images