lojmikak
Dołączył: 30 Sie 2010
Posty: 1597
Przeczytał: 0 tematów
Ostrzeżeń: 0/5
Skąd: olvovw
|
 Wysłany: Śro 1:30, 12 Sty 2011 Temat postu: ugg italia Ti-Al-Nb alloy phase transformation and |
 |
|
Ti-Al-Nb alloy phase transformation and microstructure of
. This is to experimentally demonstrate the microstructure of the alloy with two different paths in terms of the relevant crystal structure of each phase on the predicted changes in the following two possible paths are very close to the department or under the theory of freedom in the phase can stop lines at g: thermodynamic relations can be considered a reasonable assumption may be 'on the alloy l: Im3m (A2) ~ Cmcm (A20) for. In summary, TEM results show that different ~ P6s/mmc (A3) ~ P6s/mmc (DOt.) A alloy, predicted by the theory of transformation of the two paths Cmcm (O) ~ that I have is the middle of the hexagonal phase very close to the actual situation. On Ti-25A1 a ~ 14-f ~ fe12.5Nb (at), its path is to form an intermediate hexagonal phase and the formation of low DO A3 and metastable 0-phase domain structure; and close on the composition of a Ti-25AI 25Nb ( at) the base station, the path involves the formation of intermediate B19 structure and then the 0-phase domain structure of the translation. Path selection depends on the transition to the close-packed structures before the formation of the high temperature cubic B2 phase is ordered. In addition, the Taijin 1 after annealing at 700 ℃ for a long time to form a two-phase amplitude modulation organization. Morphology has the formation of metastable phase 0_ and DO. Determined by re-precipitation of gowns that the formation of two-phase structure is thermodynamically possible Spinodal mechanism. They also choose the path of the thermodynamic discussion. China Haotian Quoted ActaMet. Mater. , Vo1.42 (1994) P. 2323-2352. Ti-A Cr alloys at BU and co-phase of Y-based titanium aluminide is a promising aerospace materials, the structure of the research has been conducted for many years. In earlier studies, found only a: and the Y phase. But in recent years in some ternary TiA1 Taijin found in B phase (the third element is added to Nb, Mo, Cr and the like B stabilization element). In the Ti-Al-Nb alloy also found ∞ phase. Research has recently been focused on low volume with A1 ri a 42A1-3Cr alloy phase, and 13 ∞ phase precipitates. Alloy chemical composition as follows (wt). Elements AlICrCEN3CuFeTi content 29.39l3.32io. 040.020. o31o. They use more than 11 transmission electron microscope, scanning electron microscope, electron microprobe and x-ray diffraction and other means of B and ∞ the Taijin the study phase, the following results were obtained for a Ti 42A1-3Cr alloy p-phase To order 13, c,[link widoczny dla zalogowanych], c. Structure (a4 = 0.3197nm),[link widoczny dla zalogowanych], and found that the phase rich cr. B from the alloy phase precipitation. Xu was ordered hexagonal structure (ao: 0.452nm, C. = 0.577nm). ∞ phase and parent phase has the following orientation relationship between B t [1113d/coo01] {110} c / / {1120} h Tao Zhengxing Excerpt ~ SeriptaMet. Mater. , Vo130 (1994) P. 399,[link widoczny dla zalogowanych], TI ~ ETAIz13, a 0.2Si) is TIMET titanium matrix composites companies and other purposes developed a relatively new type of titanium-based alloys. In general,[link widoczny dla zalogowanych], p titanium alloy is heat treatable Taijin has high strength and good formability, but the drawback is that high-temperature performance (especially oxidation resistance) poor. It is reported that compared with most B Taijin, the alloy can be at a higher temperature to maintain its strength and has very good antioxidant capacity, such as the antioxidant capacity of approximately a 15-3 alloy Ti 100 times Other properties are both pretty. TIMET2] S it so attractive combination of properties can be used as high temperature metal matrix composite materials research department show that the candidate, as the combined stack composition and aging temperature does not cross phase. Phase two is a basic lanes and B Class 1 Burgers orientation relationship with a phase and the phase is {1012} Burgersa twinning orientation relationship between the two classes a phase. One of the transitional phase 13 phase, it is added in the stabilization of 13 elements in high Taijin the hcc phase separation into two different components of the bee phase is the result of j ∞ another type of phase transition phase. In addition, some containing p-si also possible to form titanium silicide phase. Although some studies have related to the mechanical properties and environmental resistance, and has been reported,[link widoczny dla zalogowanych], but more than the optical microscope scale formed by heat treatment on the microstructure analysis of the information obtained is still limited. As can by adjusting the mechanical properties of microstructure optimization, so recently the United States a l5 ~ -
相关的主题文章：
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
[link widoczny dla zalogowanych]
Post został pochwalony 0 razy
|
|
