Yang Zhen, Sun Guorui, Chen Chao
College of Mechanical Engineering and Automation, Dalian Polytechnic University, Dalian 116034, China.
Key Laboratory of Automobile Materials, School of Materials Science and Engineering, Jilin University, Changchun 130025, China.
Materials (Basel). 2025 Jan 10;18(2):280. doi: 10.3390/ma18020280.
(FeCoNi)A high-entropy alloy (HEA) is a new material with a strength similar to that of commercial Q235 structural steel, and its elongation is nearly three times greater than that of Q235 steel. Studying the welding process of the (FeCoNi)Al HEA and Q235 steel is expected to further expand the application range of commercial Q235 structural steel and provide a foundation for the engineering application of the (FeCoNi)Al HEA. This study focuses on the dissimilar welded components of (FeCoNi)Al HEA and Q235 steel and analyzes the forming quality, microstructure, and mechanical properties of dissimilar welded samples under different currents. The results show that when the welding current is above 170 A, the 3 mm sheet metal is completely penetrated, and a well-formed weld seam is obtained. The base metal of the (FeCoNi)Al HEA has an FCC structure, whereas the fusion zone of the weld seam is almost entirely a BCC structure. The microstructure of the weld seam exhibits needle-like and block-like grains that are different from those of the base metal. Owing to the difference in microstructure between the weld seam and the base metal, the average microhardness of the welded joint is twice that of the base metal. The strength of the dissimilar welded components reached 460 MPa, maintaining the tensile strength of the (FeCoNi)Al HEA, which is similar to that of the Q235 structural steel. The elongation reached over 30%, which was significantly greater than that of the Q235 structural steel.
（FeCoNi）高熵合金（HEA）是一种强度与商用Q235结构钢相似的新材料，其伸长率比Q235钢高出近三倍。研究（FeCoNi）Al高熵合金与Q235钢的焊接工艺有望进一步扩大商用Q235结构钢的应用范围，并为（FeCoNi）Al高熵合金的工程应用提供基础。本研究聚焦于（FeCoNi）Al高熵合金与Q235钢的异种焊接部件，分析了不同电流下异种焊接试样的成形质量、微观结构和力学性能。结果表明，当焊接电流高于170A时，3mm厚的金属薄板完全熔透，获得了成形良好的焊缝。（FeCoNi）Al高熵合金的母材具有面心立方（FCC）结构，而焊缝的熔合区几乎完全是体心立方（BCC）结构。焊缝的微观结构呈现出与母材不同针状和块状晶粒。由于焊缝与母材微观结构的差异，焊接接头的平均显微硬度是母材的两倍。异种焊接部件的强度达到460MPa，保持了（FeCoNi）Al高熵合金的抗拉强度，与Q235结构钢相似。伸长率超过30%，明显高于Q235结构钢。
