金属芯骨-可变区域性能复杂砂型一体化激光3D打印原理与方法

Due to the Lightweight and integrated requirements, the casting sand mold (core) is becoming more and more complex. 3D printing of complex casting sand molds is the frontier-technique and future development direction. Although the laser 3D printing sand molds with complex structures has been applied, there are many problems, such as large gas volume, core free bone, uniform material and so on. Therefore, this project proposes an integrated laser 3D printing principle and method of fabricating complex sand mold (core) with metal core bone-variable region performance. But this novel method faces the challenge of several scientific difficulties including design theory of high strength and low gas sand material, integrated laser 3D printing principle of multi-material sand molds, and interfacial bonding mechanism of different materials. This project will carry out the following research works including: first of all, the study of laser and sand thermal mechanism, research and preparation of high strength and low gas sand material system; secondly, the design principle of powder and paving material sent rolling mechanism, digital expression and control software design of multiple materials, and development of integrated laser multi-material 3D printing equipment; thirdly, interfacial bonding mechanism in the proposed 3D laser printing of dissimilar materials of sands; finally, study on the defect evolution mechanism and prediction model, and establishment of the metal core bone-variable region performance complex sand integrated design method. The achievements of this project provides theoretical and technical basis for laser 3D printing of multi-material complex casting sand molds (core) and manufacturing of high-quality casting.

铸件的轻量化和整体化要求砂型（芯）结构越来越复杂。3D打印是成形复杂砂型（芯）的前沿技术和未来发展方向，但现有技术只能成形单一材质、无金属芯骨的砂型（芯），导致透气性和溃散性差、强度低、发气量大等问题。为此，本项目提出金属芯骨-可变区域性能复杂砂型一体化激光3D打印原理与方法，但需解决高强度低发气量型砂材料设计理论、多材料砂型一体化激光3D打印成形原理、异种材料激光成形界面结合机理等科学难题。本项目拟研究激光与型砂材料热作用机理，研发高强度低发气量型砂材料；研究多材料送铺粉与滚压机制，研制多材料激光3D打印装备样机；研究激光作用下异种材料成形界面结合机理，建立多材料的激光3D打印工艺；研究复杂铸件缺陷演变机制与预测模型，建立金属芯骨-可变区域性能复杂砂型一体化设计方法。项目成果为多材料复杂砂型（芯）的激光3D打印及高品质复杂铸件的制造提供理论指导。

铸件的轻量化和整体化需求使得砂型（芯）结构越来越复杂，3D打印技术是成形复杂砂型（芯）的未来发展方向之一，现有技术只能成形单一材质、无金属芯骨的砂型（芯）。为解决此问题，本项目提出金属芯骨-可变区域性能复杂砂型一体化激光3D打印原理与方法。已完成以下研究内容：研发了高强度低发气量型砂材料制备与表征的方法；研制了多材料一体化激光3D打印装备；提出了异种材料界面结合的表征方法；实现了复杂砂型（芯）一体化成形性能区域的智能设计。最后通过装备与典型件的试制，验证了四方面的成果。结论表明，本项目最终实现了金属芯骨-可变区域性能复杂砂型一体化激光3D打印，实现高性能复杂砂型（芯）的一体化成形制造。在研究成果方面，总共发表期刊论文35篇，申请或授权专利15项，软件著作权3项。本项目的研究计划均已完成。