Titanium alloys are widely used in various fields because of their high strength, corrosion resistance, and heat resistance properties. However, at the same time, owing to the characteristics of titanium alloy, such as small deformation coefficient, high specific strength, good toughness, and so on, it is easy to produce a high temperature when milling titanium alloy, and the cutting force per unit area is large and the tool wear is serious. Especially in precision milling applications (i.e., a very small amount of material is removed), overly high milling temperatures are the main cause of tool wear and the poor surface quality of workpieces. In the actual production process, the blunt radius of the cutting edge has a significant effect on the force thermal characteristics in the cutting process. Especially in precision cutting, the cutting work is mainly completed by the cutting edge of the cutting tool, which is the first part to contact the workpiece. Changing the shape of the cutting edge has directly influenced the cutter-workpiece contact state and modifies the length of the cutter-workpiece contact state across three heat source regions, resulting in changes in the generation and transmission of cutting heat. Therefore, the blunt radius of the cutting edge has an important influence on the cutting temperature in the cutting process. Tian Xingqiang and Nie Huawei [
1] take the blunt radius of the cutting edge of a titanium alloy Ti6Al4V end milling cutter as the research object. The experimental results show that the milling temperature initially decreases, and then tends to smooth with an increasing cutting-edge radius. Mohamed N.A. Nasr [
2] has studied the turning process of austenitic stainless steel AISI 316L with different cutting radii of a cemented carbide cutter; the authors report that the cutting temperature increases with the increase of the blunt circle radius in the range of 0.02–0.1 mm. Zheng Weijuan et al. [
3] use the Advantedge 3D software to simulate the milling process of 45 steel with different cutting radii of a blunt circle radius end milling cutter. The curves of the cutting radii are increased from 0.02 mm to 0.08 mm; the authors report that the milling temperature initially decreases, and then increases with the increase of the cutting-edge radius. The lowest milling temperature occurs when the cutting-edge radius is 0.06 mm. Yang Weidong and others [
4] used abaqus to simulate the process of cutting 45 steel with a cemented carbide blade with a blunt edge. The authors report that increasing the radius in the range of 0–0.02 mm presented a decreasing cutting temperature. However, in the cutting-edge radius range of 0.02–0.1 mm, the cutting temperature gradually increases as the radius increases. In order to study the effects of the cutting edge on the hard cutting performance of the tools, Tao Liang [
5] and others have used the Advantedge finite element simulation software to simulate hardened bearing steel with five kinds of tools with different blunt radii. The research has found that the high temperature area of the cutting tools increases with the increase of the blunt radius, and the highest cutting temperature is located near the cutting edge. According to a large number of studies, when cutting titanium alloy and other difficult-to-machine materials, placing a micro-pit texture on the surface of the tool can improve the processing quality of the workpiece and prolong the service life of the tool. The micro-pit texture plays a role in grinding and anti-wear in the process, so that the cutting force and cutting temperature are reduced. The diameter, spacing, distance from the cutting edge, depth, and other parameters related to the pits have different effects on the cutting force and temperature. The reasonable selection of the parameters for the micro-texture is of great significance for improving the machining quality and cutting performance of the tool. Wang Liang [
6] made use of a laser marking machine to produce different micro-textures on the rake face of cemented carbide tools. The cutting experiments show that a micro-texture has the effect of improving cutting performance, reducing cutting force, and reducing cutting temperature. Zhang Yongbo [
7] uses the Advantedge software to simulate the turning process of cemented carbide cutting tools with a groove texture. The authors report that the insertion of a groove texture significantly reduces the cutting temperature. With the increase of the texture spacing, the cutting temperature increases slowly; with the increase of the groove width, the cutting temperature initially decreases, and then increases. Cai Xiao [
8], in order to study the influence of micro-texture on cutting force and cutting temperature, prepared micro-texture tools by the laser processing method. Through comparative tests, it is concluded that micro-texture tools can effectively reduce the cutting force and cutting temperature compared with non-texture tools. Chen Hongfeng and Lian Yunsong [
9] have studied the influence of micro-texture on cutting performance of trapezoidal groove surface with different texture parameters by finite element simulation. The results show that reasonable texture parameters can effectively improve the friction between cutting tool and chip and promote heat dissipation, thus achieving the effect of reducing the cutting force and cutting temperature. Yu Zhanjiang and Cai Qianqian [
10] have carried out high-speed cutting experiments on SUS304 stainless steel using micro-texture tools and non-texture tools. The cutting performance of micro-texture tools has been studied. The research found that the micro-groove texture and the pit texture can effectively reduce the friction coefficient of the tool surface, thus reducing the cutting force and the cutting temperature; a micro-pit texture can obviously improve the surface quality. Zhang Na and Yang [
11] have established many different types of micro-texture hard alloy models and conducted three-dimensional friction simulation tests of different types of surface micro-texture cemented carbide and titanium alloy by finite element simulation software. The results show that the groove texture can increase the heat dissipation area and significantly reduce the friction temperature, and the diamond pit texture can control the temperature increase during the friction process.
To sum up, the blunt radius of the cutting edge and the micro-texture parameters are important in improving the machinability of titanium alloys and reducing cutting temperatures. However, there are few studies on the combined influence of these two factors on the cutting of titanium alloys. Therefore, studies are urgently needed to investigate the influence of cutting-edge form and texture parameters on the processing properties of titanium alloys. In this work, a novel milling temperature model is proposed, which relies on the method of micro-element approximations and refers to the generation and conduction law of cutting heat. The proposed model is established for titanium alloy milling processes using ball end milling cutters under the action of an action of blunt edge and analyze its influence mechanism. The influencing mechanisms of different blunt radius and texture parameters on milling temperatures are analyzed. Furthermore, different blunt radius and micro-texture parameters are used to simulate and test the titanium alloy milling process; the influence of different blunt radius and micro-texture parameters on milling temperatures is also analyzed. According to the simulation and experimental results for each set of parameters, the optimal combination of the blunt radius of the cutting edge and texture parameters is obtained.