## 1 Introduction  
Electron beam welding is widely used in industry, especially in aeronautics and aerospace engineering. The weld seam connects the welded parts and the base metal after electron beam welding (EBW). The weld seam has a certain excess height, and the surface quality cannot meet the requirements. Grinding is an effective way to improve the aero-engine performance of aero-engine components. Grinding is used to treat the surface of aero-engine parts, grinding the extra height to produce a uniform surface, and improving its surface quality. Grinding has the characteristics of flexibility and precision, which are widely used in the precision processing of aero-engine parts. However, few scholars in the field of belt grinding have explored the formation mechanism of the ribbed surface by belt grinding and its influence on aerodynamic performance. Therefore, it is necessary to study the aerodynamic performance of the ground surface by belt grinding on titanium alloy EBW. Scholars have done a great deal of research on the properties of titanium alloy welded and EBW. [PERSON] et al. [1] studied the effect of electron beam scanning on the porosity generation and fatigue performance of welding joints of TC4 titanium alloy, and the results showed that electron beam scanning could reduce the porosity of welding joints and improve the fatigue performance of joints. [PERSON] et al. [2] elaborated on the relationship between mechanical strength and working life of welded joints as weak links of mechanical equipment. Experiments show that the fatigue life of the welded toe by hemispherical burr tool is 76% higher than that of the welded toe without polishing. [PERSON] et al. [3]evaluated the influence of the microstructure unevenness of the electron beam weld of TC4 thin plate on the tensile performance and low-cycle fatigue performance and found that the tensile ductility and low-cycle fatigue strength of the joint was lower than that of the base material. [PERSON] et al. [PERSON] et al. (2018) polished the toes of the welds of two different sheets of steel under different environmental conditions. The results showed that the fatigue life of the welds polished in a 3% sodium chloride environment was longer, and the fatigue strength was higher. Through experiments, [PERSON] et al. [PERSON] et al. (2018) studied the effect of welding pores on the fatigue life of titanium alloy EBW joints. It was shown that the dispersion of pore size and depth was the key factor leading to the widespread dispersion of the fatigue life of welded joints. A model of the influence of a welding pore on the fatigue life of welded joints was established. In the field of belt grinding, there is also much research, which includes robotic belt grinding technology, prediction of surface roughness of belt grinding, and precision grinding methods of aviation parts belt grinding, to name a few areas of interest. Single factor belt grinding tests of titanium alloy aero-engine blades were carried out by [PERSON] et al. [PERSON] et al. (2018). The effects of belt speed and belt feed speed on belt blockage during grinding were analyzed. [PERSON] et al. [PERSON] et al. (2018) developed an adaptive belt grinding method for an integral blade disc. The deformation error of the blade was compensated by measuring and controlling contact pressure. Precision grinding was achieved by controlling the rotating speed. Experiments showed that the method can be used as a precision processing method for the blade disc. [PERSON] (2018) developed a machine learning belt grinding system based on deep learning, which can monitor and predict the new height distribution of welding seams and the endpoint of belt grinding in extra real-time height. [PERSON] and [PERSON] et al. [PERSON] and [PERSON] (2018); [PERSON] et al. (2018) studied robot belt grinding technology from two aspects--the robot belt grinding model and surface quality--which laid a theoretical foundation for robot belt grinding technology.