基于激光烧结升温特性分析的月壤原位成型技术研究

目的分析利用激光烧结技术实施月壤原位成型的特点及方案,为月壤原位成型工程化设计和分析提供借鉴。方法基于国内外月壤原位成型技术路径,对比分析激光烧结成型技术方案的优势。通过激光照射条件下多层月壤颗粒升温模型,分析加热温度随激光器输出功率、月壤粒径、聚焦光斑直径及激光扫描速度的变化规律。基于“纪念碑”成型任务,提出一种基于封闭烧结腔和补给移动机构的激光烧结方案。结果激光烧结成型技术方案的优势是成型体性能及精度较高,无需添加辅料,非接触式,便于操作和控制,能耗及体积可接受。月壤颗粒能达到的温度取决于能够接受到的辐射能量,无论是提升激光器输出功率,还是缩小光斑直径,都能提升颗粒接受到的辐射能量密度。降低扫描速度,则颗粒接收辐射能量的时间增长,而月壤颗粒粒径变小,由于颗粒质量与粒径是三次方的关系,也能够提高单个颗粒接收到的辐照能量。激光烧结成型系统由控制装置、激光光源、补给装置、移动装置及电源组成,基于初步的分析计算,建议的系统耗能约为300 W,光斑直径为50μm,成型效率约为38 g/h。结论基于激光烧结技术路径的月壤原位成型技术具有一定的优势,建议采用低功率、小光斑、低扫描速度的技术策略,初步估算的技术指标具有工程可实现性。

Lunar Soil In-situ Forming Technology Based on Analysis of Sintering Temperature Rising Characteristics with Laser Irradiation

The work aims to analyze the characteristics and schemes of in-situ forming of lunar soil with laser sintering technology, and provide reference for engineering design and analysis of in-situ forming of lunar soil. The comparative analysis on the advantages of technical schemes of laser sintering was conducted based on the technological path of in-situ forming of lunar soil at home and abroad. The law of heating temperature changing with laser output power, lunar soil particle size, focus spot diameter and laser scanning speed was analyzed with the heating model of multi-layered lunar soil particles under laser irradiation. Based on the "monument" forming task, a laser sintering scheme based on closed sintering chamber and feeding mobile mechanism was proposed. The advantages of technical scheme of laser sintering were excellent performance and high accuracy of the forming body, no need to add auxiliary materials, non-contact type, easy operation and control, and acceptable energy consumption and volume. The temperature of the lunar soil particles depended on the radiation energy that could be received. Whether the temperature was to increase the laser output power or to reduce the spot diameter, the density of radiation energy received by the particles could be enhanced. If the scanning speed was reduced, the time for the particles to receive radiation energy would increase, while the particle size of lunar soil would decrease. As the relationship between particle mass and particle size was cubic, the radiation energy received by a single particle could also be increased. Laser sintering system consisted of control device, laser source, replenishment device, mobile device and power supply. Based on the preliminary analysis and calculation, the recommended energy consumption of the system was about 300 W, the spot diameter was 50 um, and the forming efficiency was about 38 g/h. In-situ forming technology of lunar soil based on laser sintering technology has certain advantages. It is suggested to adopt the technical strategies featured by low power, small spot and low scanning speed, and the preliminary estimated technical indicators can be realized in engineering.