Dynamic adjustment method for process parameters in selective laser sintering sub regions

Abstract

Provided is a dynamic adjustment method for process parameters in selective laser sintering sub regions. Powder bed machining plane temperature field information is detected through a thermal imager in the SLS machining process, a powder bed is divided into different regions through the detected temperature field information according to the temperature, each region to be machined is further divided into regions belonging to different temperature intervals in combination with slice contour information, the machining process parameters, such as the laser power, the scanning speed and the scanning path, used when the regions are machined are adjusted in a targeted manner, multiple times of detection can be conducted in the machining process, and the process parameters are adjusted in time according to the temperature field change. By the adoption of the dynamic adjustment method, the powder bed temperature field information can be more comprehensively used, and in combination with corresponding control operations, the more direct and precise temperature control is achieved, so that the uniformity of the temperature field of the powder bed is improved, and accordingly the quality of SLS parts is improved.

Description

technical field [0001] The invention relates to the technical field of selective laser sintering, in particular to a method for dynamically adjusting process parameters of laser selective sintering and sub-area. Background technique [0002] Selective Laser Sintering (SLS) is a rapid prototyping technology that uses laser heating powder sintering. In SLS technology, the laser beam selectively sinters the powder bed according to the layered cross-section information under the control of the computer. The local input heat source causes the distribution of the temperature field of the powder bed during the sintering process to be uneven and unstable, which makes the The control of the temperature field is extremely difficult. However, the temperature field distribution is an important factor determining the quality of SLS processing. If the temperature field gradient is too large, the material system will shrink inconsistently, which will easily cause deformation, warping and ...

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Problems solved by technology

Using the average temperature as the control basis greatly reduces the amount of information contained in the original temperature field, and cannot accurately reflect the temperature distribution of the powder bed, making it difficult to obtain an ideal temperature field control effect

[0005] In addition, most of the existing SLS temperature field control technologies are for the control of the preheating system, which does not involve the section information of the parts and the dynamic process parameter control

Regardless of the section information of the part, the pertinence of the control is reduced, and because the temperature field is constantly changing with time, if the process parameters are not dynamically adjusted, the changes in the temperature field are adjusted in time, and a single process parameter is used to control the temperature field. The sintering of the powder bed will definitely affect the control effect of the temperature field

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