Research Progress on Control Strategy of Intermetallic Compounds in Welding Process of Heterogeneous Materials

The welding of dissimilar metals is widely used in various industries and is also generally recognized by the industry. The welding of dissimilar metals is of great significance. It can not only obtain higher‐strength composite joints but also save the excessive use of rare metals and effectively expand the profit margin. The weldability of dissimilar metals is closely related to their own physical and chemical properties. Usually when the physical and chemical properties of the two metals differ greatly, their weldability is generally poor, and complex intermetallic compounds (IMCs) are easily generated during the welding process. The deterioration of joint performance is very serious. Welding of dissimilar metals is widely used in many fields such as aerospace, automobile manufacturing, and medical equipment, solving the problems of low strength, high cost, and poor corrosion resistance of the same metal joints. Regarding the welding of dissimilar metals, the current existing methods include fusion welding, pressure welding, brazing, etc. Each welding method has its own advantages and disadvantages. To obtain an effective and reliable welding joint, the simplest method is to adjust the welding parameters, but the effect is not obvious. A large amount of IMCs are generated in the weld, which has a serious impact on the joint performance. To obtain a stronger composite joint, a third transition metal can be introduced to inhibit the formation of IMCs. Under the same conditions, the introduction of the third metal can significantly optimize the performance of the composite joint. In the weld, significantly reducing the number of IMCs to a large extent reduces the deterioration of the joint performance of the newly formed IMCs, but there is still a small amount of IMCs formation. To completely avoid the formation of IMCs, special joint composite intermediate layer is introduced, which completely avoids the influence of newly generated IMCs on joint performance. In the welding process of dissimilar metals, selecting the appropriate welding method and welding process can obtain a composite joint with excellent performance.