激光增材制造过程中循环热输入对组织和性能的影响

Review on Effects of Cyclic Thermal Input on Microstructure and Property of Materials in Laser Additive Manufacturing

激光增材制造(LAM)中逐层沉积形成独特的循环热输入,能对沉积材料产生原位热处理(IHT)效应,具有调整微观结构和提高材料力学性能的潜力。本文针对LAM中循环热输入现象进行了详细阐述,分析了工艺参数、沉积方向、层间延时、基板预热、激光重熔等对循环热输入的影响行为。不同的循环热输入能对晶粒取向、相组成、第二相析出等微观组织产生明显的影响,进而影响其力学性能。循环热输入产生的IHT效应,为改善材料性能和研发新材料提供了契机。因此本文提出了理解和建立成分-工艺-IHT效应-组织结构-力学性能之间关系的理论,进而为基于IHT效应的LAM专用新材料的研究和发展提供启示。

The unique cyclic thermal input in laser additive manufacturing(LAM)induced by layerwise deposition manner has been one of the hot research topics.This technique has shed light on the potential of using intrinsic heat treatment(IHT)to tune microstructures and enhance the mechanical performance of materials.Therefore,this article elaborates on cyclic thermal input in LAM.Herein,the influence of process parameters,deposition direction,interlayer delay time,substrate preheating,and laser remelting on cyclic thermal input was reviewed in detail.One of our key findings was that the cyclic thermal input can significantly affect the microstructures such as grain orientation,phase composition,and second phase precipitation,which in turn affects the mechanical properties of materials.The IHT effect generated by cyclic thermal input provides an opportunity for material performance enhancement and new materials development.Hence,the understanding of internal relationships among composition-process-IHT effectmicrostructures-mechanical properties is critical.This is not only essential for material performance enhancement through tailoring of IHT effect but also provides enlightenment for the research and development of LAM-specific new materials based on IHT effect.