Affiliation:
1. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China
2. Nanjing High Speed & Accurate Gear (Group) Co., Ltd., Nanjing 211100, China
Abstract
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.
Funder
National Science and Technology Major Project
Subject
General Materials Science
Reference28 articles.
1. Analysis of Hard Machining of Titanium Alloy by Taguchi Method;Kumar;Mater. Today Proc.,2017
2. Optimization and influence of process parameters on surface roughness in turning of titanium alloy;Ramana;Mater. Today Proc.,2017
3. Sun, J., Huang, S., Wang, T., and Chen, W. (2018, January 11–13). Research on surface integrity of turning titanium alloy TB6. Proceedings of the CIRP Conference on Surface Integrity, Tianjin, China.
4. Measurement and analysis of surface roughness in turning of aerospace titanium alloy (gr5);Ramesh;Measurement,2012
5. Tool life and surface integrity in turning titanium alloy;J. Mater. Process. Technol.,2001