Firstly, the reasonable selection and optimization of welding process parameters is the key to improving joint strength. The main process parameters of friction welding include rotational speed, friction pressure, upsetting pressure, friction time, and upsetting time. These parameters directly affect the generation of friction heat and the plastic flow of materials. For example, appropriately increasing the rotational speed can increase the friction heat input per unit time, which helps to soften the material and promote the flow and diffusion of plastic metals; however, excessive speed may lead to local overheating or burnout, which反而 reduces the joint strength. Therefore, in practical applications, parameter optimization should be carried out according to material properties, welding structure, and equipment capabilities to achieve good plastic deformation and dense bonding.

　　Secondly, the material matching between the base material and the weldment also has an important impact on the joint strength. In the welding of dissimilar materials, due to the differences in thermal expansion coefficient, thermal conductivity, and plastic deformation capacity, stress concentration or brittle interfacial phases are prone to occur, thereby reducing the joint performance. By selecting appropriate transition materials, controlling the welding temperature and cooling rate, and other methods, the interface bonding state can be improved, and the overall strength of the joint can be increased.

　　Furthermore, the intermetallic diffusion and plastic deformation formed during the friction welding process are also important mechanisms for improving joint strength. Under the combined action of high temperature and high pressure, the metal at the contact interface undergoes plastic deformation, oxides and impurities are extruded out, and clean metal surfaces are exposed to promote the diffusion and bonding between atoms. This metallurgical bonding method is more stable than the solidification bonding of fusion welding, and can significantly improve the tensile and fatigue strength of the joints.



In addition, post-weld heat treatment is also an important means to improve the strength of friction welding joints. Proper heat treatment can eliminate residual stresses, refine grain size, and improve the uniformity of the microstructure, thereby further enhancing the mechanical properties of the joints.

　　In summary, by scientifically optimizing welding parameters, reasonably selecting material combinations, controlling the interface bonding quality, and reasonably applying post-welding treatment technology, friction welding can significantly improve the joint strength to meet the manufacturing requirements of high-performance structural components. With the continuous development of materials science and welding technology, friction welding will play an increasingly important role in more advanced manufacturing fields in the future.