air jordans Mo-based alloy at high temperature, is

Mo-based alloy at high temperature, isothermal fatigue and thermo-mechanical fatigue

Characteristics of isothermal fatigue and TMF designed three types of tests, including 350 ℃ and 500 ℃ isothermal fatigue test, and the temperature of 350 ℃ ~ 50o ℃ triangle waveform area to ask the temperature cycling conditions hereinafter relative to thermo-mechanical fatigue testing. As Taiwan TZM metal brittle material, to be completed under the control strain was stabbed when fatigue tests difficult, therefore, all tests were applied to control the average load of zero completed under stress conditions. The size of the isothermal fatigue test stress were 800MPa1000MPa, 1200MPa; thermal mechanical fatigue test for the 800MPa900MPal000MPa and I200MPa. All tests were carried out to sample failure, which completely broken up. The applied stress for the triangular waveform, the period of lmin,[link widoczny dla zalogowanych], cyclic stress R = I 1. In the thermo-mechanical fatigue test, the cyclic temperature and mechanical stress at the same time l, / a phase change with the South, that the maximum tensile stress occurs coincident with the maximum temperature, the maximum compressive stress occurs coincident with the lowest temperature. At 350 ℃ and 500 ℃ isothermal fatigue tests, fatigue life was no significant difference, indicating that, in this temperature range, the material to maintain a good high-temperature fatigue strength,[link widoczny dla zalogowanych], however, compare TMF test data then please Chu found that in-phase thermo-mechanical the fatigue life under fatigue is lower than when the same stress under isothermal fatigue life of fatigue. In all tests were observed phenomenon of spike relaxation,[link widoczny dla zalogowanych], its direction is not the same. 800MPa and 1000MPa in the 350 ℃ isothermal fatigue, hysteresis loop first in the compression direction and the fatigue life of each of the 2% and 9% for the period, and then reverse direction along the stretch until the fracture. 800MPa to 500 ℃ in the isothermal fatigue test and the same village under the TMF strength test, the direction of hysteresis loop in the compression start moving only in the continuous fatigue life test of 0.5% to 1. O%. In other experiments, hysteresis loop from beginning to end only in the tensile direction in the trial were also observed hysteresis loop in the direction of increasing tensile rate of movement. The first cycle occurs only very small plastic strain (\Regardless of the isothermal or thermo-mechanical conditions, the stress is almost the flexibility to increase or decrease. Then a continuous increase in plastic strain. Before breaking until the sample reaches a maximum. (To 800MPa and 1200MPa test, the maximum value greater than 0.36%, respectively, and so at 1.0%). At. nF test, plastic strain from the 30% of the total number of cycles increases began to accelerate: The isothermal fatigue, the total teaching from the loop: Application and Market: 40% ~ 45% of the beginning, accelerate the increase in plastic strain. 800MPa and 1000MPa experiments in isothermal fatigue of the plastic strain is greater than thermal-mechanical fatigue of the plastic strain Sui. This indicates that the scope of this stress TMF tests. Materials showed less softening and a shorter cycle life. Only 1200MPa isothermal fatigue tests the plastic strain is lower than TMF tests, and in this case, the fatigue life test is very short, lasted only very few cycles, plastic strain energy density and the plastic directly on the number of cycles have become the same growth trend. In the first fatigue cycle, can be observed in a very narrow hysteresis loop, and then cycle a few more too,[link widoczny dla zalogowanych], the wider the hysteresis loop, before breaking,[link widoczny dla zalogowanych], hysteresis loop maximum. By scanning electron microscopy (SEM) observation, the isothermal fatigue at 800MPa and TMF test, the section seems to have very small fatigue crack growth toughness (FCP) area and a large brittle - Pi area, in the FCP area, there are a lot of micro- cracks and inclusions. In l000MPa the TMF test, the specimen was found FCP fracture zone seems to be completely brittle fracture, the fracture was also observed on the micro-cracks. Many micro-cracks in the TMF tests than 800MPa in the cracks to be too, in the vicinity of these cracks were also observed zirconium, thorium inclusions. In l200MPa the TMF test, also found in the same experiment with l000MaTMF characteristics, due to cyclic loading increased, a number of micro-cracks in the micro-cracks than l000Mea test too. (Drawer Yin Hu Xu Qingqi) f, (, i /, if, titanium super market down .. r: (! 10 U.S. titanium industry in China has changed. Although thorium emerge. But confidence has dropped significantly from a year ago . industry producers and processors who are still on the industrialization of this 50 years ago, who was expected in 1999 demand, production and prices will be under the production of metal rich cautiously down the long-term applications. Th-industrial boom for several years After the boom, has been optimistic, and firmly believe that new applications of thorium will continue to peak in. · ll ·

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