多材料砂型增材制造一体化共面铺砂工艺研究

Research on Integrated Co-planar Sand Laying Process for Multi-material Sand Mold Additive Manufacturing

目的针对复杂薄壁铸件高性能制造难题,本研究提出多材料砂型增材制造一体化共面铺砂工艺,实现多材料砂型的整体成形。方法基于多材料砂型增材制造振动铺砂装置,通过优化固化剂含量、铺砂器开口宽度和振动频率,实现两种型砂材料的定量落砂。通过显微镜扫描表征和图像处理,系统地研究了在不同铺砂速度下的铺砂质量和型砂层厚变化规律。结果在一定范围内,固化剂含量的增大会减小落砂流量,铺砂器开口宽度与振动频率的增加均提高落砂流量,当硅砂固化剂含量为2.3wt.‰、铬铁矿砂固化剂含量为2wt.‰、铺砂器开口宽度为2mm、振动频率为500Hz时,两种型砂落砂流量相等;在此基础上,铺砂速度提高会增加模糊长度,降低铺砂界面连接处和铺砂末端粗糙度。当铺砂速度为53.92mm/s时,实现0.6mm层厚的多材料稳定持续铺砂,界面连接效果好、铺砂精度高。结论本研究突破多材料砂型增材制造一体化共面铺砂工艺,实现多材料砂型多区域定量均匀铺砂。

The work aims to propose an integrated co-planar sand laying process for multi-material sand mold additive manufacturing,to achieve the holistic formation of multi-material sand molds and address the challenges in manufacturing high-performance complex thin-walled castings.A vibratory sand laying device was used for multi-material sand mold additive manufacturing.The curing agent content,opening width of the sand laying tool,and vibration frequency were optimized to achieve quantitative sand laying for two types of molding sand materials.Through microscopic scanning and image processing,the quality of sand laying and the variation of sand layer thickness at different laying speeds were systematically investigated. Within a certain range, increasing vibration frequency and opening width both increased sand falling flow rate, while an increase in curing agent content reduced the sand falling flow rate. When the curing agent content was 2.3wt.‰ for silica sand, the curing agent content was 2wt.‰ for chromite sand, the sand laying tool opening width is 2 mm, and the vibration frequency is 500 Hz, the sand falling flow rate for two types of molding sands was equal. On this basis, increasing laying speed increased the fuzzy length and decreased the roughness at the sand laying interface and the end. At a laying speed of 53.92 mm/s, stable and con-tinuous laying with a thickness of 0.6 mm for multiple materials was achieved, demonstrating good interface connectivity and high laying precision. This study breaks through the integrated co-planar sand laying process for multi-material sand mold addi-tive manufacturing, achieving quantitative and uniform sand laying for multiple materials in different regions of the sand mold.