钛合金材料的车削加工会影响材料的表面结构,并导致其使用寿命的变化。在本文中,通过弯曲疲劳试验研究了TC17钛合金车削试样的疲劳行为。然后讨论了热耦合作用下的疲劳寿命变化规律。这揭示了TC17的疲劳断裂机理;裂纹起源于源区的表面,瞬态断裂区域为韧性断裂。车削参数和表面完整性的数学模型(粗糙度,建立了显微硬度和残余应力),用数学关系式分析了车削参数对疲劳寿命的影响。得出结论,车削参数对常温下疲劳寿命的影响如下:进刀>切削深度>切削速度。vc=30m/min的疲劳寿命,f=0.25mm/r,ap=0.3mm,每周只有40,586个周期,vc=30m/min的疲劳寿命,f=0.05mm/r,ap=0.1mm每周有539,400个周期,也就是说,疲劳寿命最长是最小的16.6倍。切割速度小,饲料,在保证实际加工效率的基础上,可以选择较大的切削深度。TC17试样经过一定的循环后发生疲劳断裂,揭示了疲劳断裂机理。
The
turning process of titanium alloy material will affect the surface structure of the material and lead to a change in its service life. In this paper, the fatigue behavior of the TC17 titanium alloy
turning sample was studied through the bending fatigue test. The fatigue life variation rule under the action of thermal coupling was then discussed. This revealed the fatigue fracture mechanism of TC17; the cracks originated from the surface of the source region, and the transient fault region was a ductile fracture. The mathematical model of
turning parameters and surface integrity (roughness, microhardness and residual stress) was established, and the influence of
turning parameters on fatigue life was analyzed with a mathematical relationship. Drawing a conclusion, the effects of
turning parameters on fatigue life at normal temperature are as follows: Feed > Cutting depth > Cutting speed. The fatigue life of vc = 30 m/min, f = 0.25 mm/r, ap = 0.3 mm is only 40,586 cycles per week, the fatigue life of vc = 30 m/min, f = 0.05 mm/r, ap = 0.1 mm has 539,400 cycles per week, that is, the longest fatigue life is 16.6 times the smallest. Small cutting speed, feed, and large cut depth can be chosen based on ensuring practical processing efficiency. The fatigue fracture of the TC17 sample occurred after a certain cycle, and the fatigue fracture mechanism was revealed in this paper.