Effect of Microstructure on Time-dependent Fatigue Sensitivity of TC11 Alloy at High Temperature

Effect of microstructure on the fatigue resistance of the alloy at high temperature and temperature Zhou Yigang, Zeng Wei School of Materials Science and Engineering, East West University of Science and Technology, Xi’an 710072, Effect of high temperature and time fatigue resistance, results show that, when, the peak cycle time 3min. The microstructure of the TCll alloy showed a significant decline in fatigue life, which is the largest decline in isometric tissue, followed by state organization. The basket organization is the smallest. SENI and TEM observations show that the time-dependent sensitivity of equiaxed and conditioned structures is characterized by a large number of quasi-cleavage fractures and rut-like plane slips, and quasi-cleavage fractures and plane slips decrease with decreasing equiaxed phases. The net basket organization showed cyclical faults and dislocations. In this paper, the plane slip is explained by the model of dislocations cut through 2 particles. Creep mechanism was used to analyze the effect of species on the time-dependent fatigue sensitivity.

Since titanium alloys have been used to manufacture jet engine compressor discs, their time-dependent fatigue sensitivity has been the focus of attention since discs work under the interaction of fatigue and creep stress. The time-dependent fatigue sensitivity is affected by many factors, such as working temperature component cross-section size 31 loading level stress biaxiality 4 texture orientation 1 etc., among which the microstructure is an important influence factor. At present, the study of D 614, 685, and 16246 microstructures on the fatigue sensitivity of high temperature and time fatigue has been received by the countries in the world. The date of receipt is 20000302, and the date of receipt of the revised manuscript is 20000612. In particular, the former two are mostly 1. In China, D 0 Alloys have been used to make a variety of engine-compressor plates, but so far there has been little coverage of the study of microstructures' fatigue sensitivity to fatigue. 571. The experimental results presented here supplement the deficiencies of previous studies.

1 Experimental method In order to compare the different kinds of microstructures on the shadow sensitivity of the time-dependent fatigue sensitivity, the seedlings were used to forge a disc with a diameter of 500 and a disc member with a diameter of 500. The discs that were conventionally forged were equiaxed. The tissue 990 is near to the skeleton, and it is organized as a state organization, and the 1020 is forged as a net basket 1 1 often, nearly 3 with this, and the skeleton of the skeleton is formed at each time the peak of the loop is 3 along the longitudinal direction of the specimen. Take the metallographic test Xiang Xiang, use the light filial metallography and scanning electricity, and observe the metallographic structure and appearance of the sample, and the fracture is pending. Follow the test and cut the sample. Transmission electron microscopy was used to observe the dislocation patterns under interaction.

2 Real-world results 2.1 Cycling and time-saving attack The Laura experiment measured the appropriate intensity of isometry of the isometric state and the basket structure, and the anti-variation performance of the equiaxed structure was significantly lower than that of the basket. Also lower than the state organization; 20C, 715, the low-cycle fatigue luxury is followed by fatigue, and become interactive. The maximum stress on the fatigue life of equiaxed, state and basket structures is related to 2, from which it can be seen that the microstructures of the species all have the time-dependent fatigue sensitivity 2 on the left experimental point. Peak time after 3 hours. The fatigue life of specimens in different tissues was significantly reduced. It's just different degrees and embarrassing. The fatigue life of equiaxed woven fabrics decreased the most, followed by state organization. Net basket organization is the smallest.

That is, the organization of the basket is fatigued and the performance is most severe. This is due to the interaction between the 3,4803 reported in Document 8 and the isometric state and basket organization. The external values ​​obtained were 2529, 8298 7,0, respectively.

A kind of incandescent light, time and non-timekeeping conditions, labor life along the disk chord sample interception. The specimen diameter of 6 and the gauge length long-time circulation experiment were carried out on an improved 13 high-pass fatigue field machine. The fatigue life was 5201. The rate is 0.33 è·„. According to the range of stress relieving of the retracted tissue, the strain time curve corresponding to the three kinds of tissues can be expressed.

The strain accumulation rate and strain-average ratio of equiaxed structure and the basket structure are high under the same cyclic stress conditions. The strain basket product has the smallest strain product. The 2.2 fracture view has a large number of quasi-scientific planes in the fatigue zone of the equiaxed structure. The various types of fatigue are distributed in the grain-boundary private and sub-grain 35, and the apology-like plane-level structure has emerged, and this type of structure and fatigue-preserving overtime have emerged. Significantly reduced life expectancy closely related to 19; another kind of sub-crystal or cellular structure, please 54. This means that the change in the accumulation of sleeves, in the process of repairing time, plays an important role. In the state organization. In sleeves, crystals are also considered to be mainly unplanned, but the spacing between the sliding jaws is widened, the chessboards are covered, and the stripe-like structure of the strips in the tissue structure is similar to that of the baskets. Bit 5 of the Silver Network 3 discusses patterns and sub-links less 4; in the crack propagation area, the fracture pattern changes from quasi-cleavage fracture to empty mud nucleus dimple fracture 44. State structure is also accurate. The main reason is that there is a seizure withheld by the cup.

The basket-weaving-weaving fatigue zone in Australia is a typical example of Yin-Li-Li-Fang fault, and the three-dimensional structure of equiaxed weaves under variable interaction is 3, and it is believed that the quasi-cleavage cleavage probability under the condition of time fatigue is The increase is related to the occurrence of plane slippage 3 because the crack growth stage at the first stage is fractured along a slip band, and the crack tip stress field is coplanar with the cracking surface, resulting in flattening of dislocations. Isometric, internal principal, and dislocation characteristics.

Liu Shou-yi et al. studied the 500-stress hot-tempered mud of D 0 alloy, which was similar to the flat-slip displacement sonar feature. When the phase volume fraction increased, the dislocations were not bypassed but cut. In order to cut the indium grain, the 4 gods organized the shear stress of the 1 urinary oxime from the residue field 5 to the police (1) as the body weight fraction of the grain. For the average particle size of 2 pellets.

After the oak cut 2 over. The average diameter of the 2 indium particles decreases. According to wait. If the position is too thin, the drag will be reduced and the slip will be easy, resulting in a flat slip. The dislocation structure of the equiaxed structure is dominated by plane slip, so the isochronal microstructure has the lowest time-dependent fatigue life.

system. This station fruit was obtained under the stress heat exposure of D0 alloy 5001. No flaws will promote the diffusion of oxygen atoms from the environment to the crack tip, resulting in the formation of oxygen-rich crack tips! Layers and materials, become brittle due to oxygen and yttrium stable isometric fatigue life Mingkun reduced the circumference 2.

The anti-transmutation properties of the alloy are related to the sleeve-like orientation of the sleeves in the New Zealand weave. The reference 9 refers to mountains, strips, and isosceles, and the metamorphosis of a better metamorphic mechanism is a slow deformation. In an isometric tissue, the slip deformation is first observed in one and the grains in the grain are opened and the strain is increased. Slips will take up more planting, grains. Afterwards, the surrounding 3 crystals were expanded by the transformed crystal grains, so that the nucleation of the empty crystals was later. But empty nucleation. The rapid expansion of the formation of quasi-mechanical fractures 4 can occur; slipping in the basket organization creates a severe plug-in accumulation at the crystal defects. This has promoted the hollow shape of shuttles and the development of Shaanxi. However, due to the intertwined flakes, slipping increases the difficulty of dices despite the early nucleation of holes. However, it is difficult to expand.

The formation of intragranular damage shows obvious cleavage fracture characteristics 囝4; the state 9 organization has the creep characteristics of the former two. The voids are difficult to nucleate and are not easy to expand, so the signs of cleavage in the extended zone are not obvious. The quasi-cleavage fracture is dominated by the above analysis, under the interaction of fatigue creep. Fatigue life is associated with the microstructure of the alloy and the creep properties of the microstructure. In equiaxed and tempered structures, ruthenium-like plane dislocations are formed within the grains, and dislocations within the grains are formed in the weave. For the intertwined dislocation network, combined with the creep resistance of the basket organization, the highest fatigue life is achieved.

4 Conclusions The isometric and basket organization of the D-0 alloy specimens. In the fatigue test, the peak time of each cycle is 3min, that is, under the interaction of fatigue and creep, all of them have the time-dependent fatigue sensitivity, and the fatigue life is significantly reduced. The equiaxed structure has the largest drop, the state organization is centered, and the fatigue and creep performance of the basket structure is the best...

The fracture of fatigue fracture is not the origin of fracture center of ten specimens, but originates from the fatigue source region of the plane and equiaxed structure. The quasi-cleavage fracture dominates, the state organization has the characteristics of cyclic cleavage, and the basket organization is a typical cycle. Cleavage fracture.

The dislocation morphology of the equiaxed structure is a car-like planar slip dislocation or cyst dislocation, and the state structure is strip-shaped. The dislocation structure of the isometric structure and the pure net basket organization are tangled dislocation networks.

The time-dependent fatigue life of the alloy is closely related to the creep life of the microstructure. The creep resistance of the basket is best. Therefore, the fatigue life under fatigue and creep interaction is the best.

Liu Suyu, Xiong Yuehua, Li Lijia, Gao Yang, Li Yaguo, Cao Chunxiao. Zhang Taixian. Chin Science and Engineering, The 6th National Academic Symposium on Titanium and Titanium Alloys, Beijing Atomic Energy Press, 1987, Zhou Yigang, Zhang Baochang. Journal of Aeronautics, 1989; 1064