Preparation and defocusing forming method of low-cost ceramic powder for selective laser melting

Abstract

The invention relates to a preparation and defocusing forming method of low-cost ceramic powder for selective laser melting. The preparation and defocusing forming method comprises the following steps: preparing powder or a powder mixture of a ceramic material; design import and layer cutting of a CAD model; using a roller for carrying out powder laying and powder pressing procedures on the prepared powder or powder mixture of the ceramic material, and obtaining a powder layer blank; controlling the forming cylinder to ascend and descend, and putting the powder layer blank in a defocusing state; heating the specific area of the powder layer blank to the highest temperature through a melting heat source, and integrating solidification and densification after melting and cooling; judging whether all cutting layers are completed or not; recovering the powder raw material and taking out the formed part. According to the method, the low-cost irregular ceramic powder is fully utilized so that the raw material cost can be saved; the temperature field distribution of the molten pool is optimized through defocusing printing, and the temperature gradient is reduced. With application of the method, the problems of high requirements on SLM ceramic powder, harsh processing conditions, complex and cumbersome process and post-treatment, high part preparation cost, insufficient performance andthe like are solved.

Description

technical field [0001] The invention relates to the technical field of additive manufacturing, in particular to a low-cost laser selective laser melting (Selective Laser Melting, SLM) ceramic powder preparation and defocused forming method thereof. Background technique [0002] Ceramics and ceramic-based composites have excellent properties such as light weight, high temperature resistance, low thermal conductivity, insulation, and chemical stability, and are widely used in aerospace, electronic devices, biomedical, and building materials. Ceramic additive manufacturing technology is an advanced emerging manufacturing technology, which has the advantages of customization, high degree of design freedom, and environmental protection. It can realize the rapid design of complex structural ceramic parts, and has received widespread attention and rapid development. It is expected to promote A new round of technological change in the manufacture and application of ceramic materials...

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Problems solved by technology

At present, research reports on SLM ceramics at home and abroad all use the spherical powder produced by the atomization granulation method as the raw material. The cost is high; in addition, ceramic materials are sensitive to stress and cracks, and laser beam irradiation causes a high temperature gradient in the molten pool area, so that the formed part is repeatedly subjected to thermal shock and cracks during the heating and cooling process, and the performance of the formed part is improved. Bad hidden dangers. At this stage, the method of high temperature preheating not only requires high equipment, complicated process, but also has extremely low efficiency and cannot completely suppress cracks, which limits the research and development of this technology.

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