Wu Ying, Guo Kaibo, Ni Junfang
Institute of Intelligent Manufacturing and Smart Transportation, Suzhou City University, Suzhou 215104, China.
School of Mechanical and Electrical Engineering, Soochow University, Suzhou 215137, China.
Materials (Basel). 2024 Nov 21;17(23):5691. doi: 10.3390/ma17235691.
In this study, three stainless steel materials (17-4PH, 316L, and 304) were experimentally simulated using metal injection molding (MIM) technology to explore the size shrinkage behavior and defect formation mechanism of materials with different particle sizes during sintering. The sintering environment was linearly heated to 1250 °C at a rate of 5 °C/min and kept warm for 90 min. Multi-physics field coupling analysis was performed using ANSYS Workbench software. Two different regions were selected to simulate the total deformation trend of the material during sintering. The simulation results were compared with data from SEM and EDS analyses to elucidate the influence of particle size on shrinkage behavior and defect distribution. The findings indicate that the gaps between particles far away from the gate position became larger, the degree of densification decreased, the porosity was higher, and the number of white dot inclusions increased. Among the three materials, 17-4PH, which had the smallest particle size, had a greater sintering driving force, a better degree of densification, a smaller predicted total deformation, and a higher shrinkage rate, which is consistent with the hardness test data and the actual density data. In addition, the densification advantage of small particle size powder is not only related to surface energy but is also closely linked to the uniformity of its microstructure. The analysis in this study further promotes the performance optimization of stainless steel materials, indicates a scientific basis for future process improvements and high-precision parts manufacturing in MIM technology, and points to the development direction for high-performance materials.
在本研究中，使用金属注射成型（MIM）技术对三种不锈钢材料（17-4PH、316L和304）进行了实验模拟，以探究不同粒径材料在烧结过程中的尺寸收缩行为和缺陷形成机制。烧结环境以5℃/min的速率线性加热至1250℃并保温90分钟。使用ANSYS Workbench软件进行多物理场耦合分析。选择两个不同区域来模拟材料在烧结过程中的总变形趋势。将模拟结果与扫描电子显微镜（SEM）和能谱仪（EDS）分析的数据进行比较，以阐明粒径对收缩行为和缺陷分布的影响。研究结果表明，远离浇口位置的颗粒间间隙变大，致密化程度降低，孔隙率更高，白点夹杂物数量增加。在这三种材料中，粒径最小的17-4PH具有更大的烧结驱动力、更好的致密化程度、更小的预测总变形和更高的收缩率，这与硬度测试数据和实际密度数据一致。此外，小粒径粉末的致密化优势不仅与表面能有关，还与其微观结构的均匀性密切相关。本研究中的分析进一步推动了不锈钢材料的性能优化，为MIM技术未来的工艺改进和高精度零件制造指明了科学依据，并指出了高性能材料的发展方向。
