铸造砂型3D打印后处理工艺对变壁厚砂型变形行为研究

Study on the Deformation Behavior of Variable Wall Thickness Sand Mold by a 3D Printing Posttreatment Process

近年来,基于微滴喷射原理的砂型3D打印技术取得了较快的发展,吸引了工程技术人员的广泛关注。然而,目前的砂型3D打印技术后处理工艺会造成变壁厚砂型产生变形的问题。本文采用仿真分析与实验研究相结合的方法定性分析了砂型在后处理过程中发生变形的原因,定量研究了壁厚变化和后处理温度对砂型变形行为的影响规律。研究发现,3D打印砂型后处理过程中不均匀的温度场分布造成了砂型的热应力变形,打印砂型的厚度变化越大以及后处理温度越高产生的变形量越大。针对该问题本文提出了基于辊子压实与分层加热的辅助成形装置和方法,有效消除了砂型后处理变形问题,为砂型3D打印的工程应用提供了理论指导。

In recent years, sand-type 3D printing technology based on the principle of droplet ejection has achieved rapid development, attracting increasing attention from engineers and technicians. However, the current sand mold 3D printing technology postprocessing process causes the problem of deformation of the variable wall thickness sand mold. In this paper, the combination of simulation analysis and experimental research was put forward to qualitatively analyze the cause of sand mold deformation during posttreatment and then quantitatively study the influence of wall thickness variation and posttreatment temperature on sand mold deformation behavior. It is found that the uneven temperature field distribution during the posttreatment of the 3D printing sand mold can cause the thermal stress deformation of the sand mold, which will intensify with the increasing thickness variation of the printing sand mold and posttreatment temperature. Aiming at this problem, an auxiliary forming device and method based on roller compaction and layered heating is proposed, which effectively eliminates the problem of sand posttreatment deformation, providing theoretical guidance for the engineering application of sand 3D printing.