| Popis: |
The purpose of this paper was to reveal the evolution law and mechanism of surface integrity parameters of TA19 titanium alloy end face, and to provide a basis for the process control of blisk surface integrity. Taking faced TA19 titanium alloy fatigue specimens as the research objects, the fatigue tests were carried out at 20 ℃ room temperature and 400℃ high temperature. The evolution law of surface integrity parameters during the whole loading process was analyzed by setting detection nodes in the total fatigue cycle number range. The results show that under the action of low cycle fatigue at room temperature, the fracture is near brittle, and under the action of low cycle fatigue at high temperature, the fracture is obviously ductile. The amplitude and frequency of surface waviness increased sharply with the increase of fatigue loading cycles at room temperature and 400℃. Surface roughness is rarely changed under room temperature fatigue tests, but decreased with the increase of fatigue cycles at 400℃. At room temperature, the surface residual compressive stress almost does not change significantly with the increase of fatigue loading cycles, but decreased exponentially at high temperature, which is in accordance with Zener-Wert-Avrami model. Therefore, in the process of material preparation and machining, it is necessary to improve the internal material uniformity of the blank, reduce the corrugation of the machined surface, and increase the amplitude of residual compressive stress on the machined surface, in order to prolong the fatigue life under the action of high temperature fatigue. |
