Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Investigation of Low Temperature Creep Deformation Behavior of a Metastable Beta Titanium-14.8Wt%Vanadium Alloy
Author: An Experimental and Theoretical Investigation of the Low Temperature Creep Deformation Behavior of Single Phase Titanium Alloys
Author: Paul Gregory ObersonFundamental Studies on Ambient Temperature Creep Deformation Behavior of Alpha and Alpha-beta Titanium Alloys
Author: Charles Arthur GreenePublisher:
ISBN:
Category : Titanium alloys
Languages : en
Pages : 392
Book Description
Systematic studies were undertaken to determine the ambient temperature tensile and creep deformation behavior, including mechanisms, of alpha Ti-Mn, and alpha-beta and beta Ti-Mn and Ti-V alloys. In regard to the a Ti-Mn alloy, it was found that when creep tested at 95% of the 0.2% Yield Stress (YS) the creep strain of the coarse grained (500 microns) material was significantly higher than the fine grained (45 microns) material. This effect was found to be due to the scientifically interesting phenomenon of time dependent twinning in coarse grained alpha phase. Such a phenomenon has never been reported before. Based on optical and scanning electron microscopic observations of displacements of the grid lines obtained by electron lithography and transmission electron microscopic observations, it was found that there are strong slip/twin, twin/slip and twin/twin interactions during creep deformation. The tensile deformation of beta titanium alloys depended on the alloying elements. In the beta Ti-Mn alloy the tensile deformation mechanisms were found to be coarse and wavy slip whereas in the beta Ti-V alloy the deformation mechanisms were found to be coarse and wavy slip as well as twinning. This difference was attributed to the difference in stability of the beta phase. In contrast to the a Ti-Mn alloy the creep deformation in the beta Ti-Mn alloy was found to be negligibly small at a stress level of 95% YS. With respect to alpha-beta titanium alloys, for similar volume percent and morphology of phases, the tensile and creep deformation mechanisms were also found to depend on the alloying elements. In regard to the alpha-beta Ti-Mn alloy, the deformation mechanisms were found to be predominately fine slip in alpha and beta phases and occasional interface sliding.
Fundamental Studies on Ambient Temperature Creep Deformation Behavior of Alpha and Alpha-Beta Titanium Alloys
Author: Charles Arthur GreenePublisher:
ISBN:
Category : Titanium alloys
Languages : en
Pages : 0
Book Description
Systematic studies were undertaken to determine the ambient temperature tensile and creep deformation behavior, including mechanisms, of alpha Ti-Mn, and alpha-beta and beta Ti-Mn and Ti-V alloys. In regard to the a Ti-Mn alloy, it was found that when creep tested at 95% of the 0.2% Yield Stress (YS) the creep strain of the coarse grained (500 microns) material was significantly higher than the fine grained (45 microns) material. This effect was found to be due to the scientifically interesting phenomenon of time dependent twinning in coarse grained alpha phase. Such a phenomenon has never been reported before. Based on optical and scanning electron microscopic observations of displacements of the grid lines obtained by electron lithography and transmission electron microscopic observations, it was found that there are strong slip/twin, twin/slip and twin/twin interactions during creep deformation. The tensile deformation of beta titanium alloys depended on the alloying elements. In the beta Ti-Mn alloy the tensile deformation mechanisms were found to be coarse and wavy slip whereas in the beta Ti-V alloy the deformation mechanisms were found to be coarse and wavy slip as well as twinning. This difference was attributed to the difference in stability of the beta phase. In contrast to the a Ti-Mn alloy the creep deformation in the beta Ti-Mn alloy was found to be negligibly small at a stress level of 95% YS. With respect to alpha-beta titanium alloys, for similar volume percent and morphology of phases, the tensile and creep deformation mechanisms were also found to depend on the alloying elements. In regard to the alpha-beta Ti-Mn alloy, the deformation mechanisms were found to be predominately fine slip in alpha and beta phases and occasional interface sliding.
Creep, Fatigue, and Deformation of Alpha and Alpha-beta Titanium Alloys at Ambient Temperature
Author: Matt C. BrandesPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Abstract: Titanium and it alloys are extensively utilized in critical applications that require materials with high strength to weight ratios, rigidities, and toughnesses. This being the case, over 70 years of research have been devoted to the measurement, understanding, and tailoring of the mechanical properties of these alloys. Despite these efforts, surveys of the current knowledge base and understanding of the mechanical responses of Ti alloys demonstrate that numerous mechanical behaviors have yet to be investigated and explained. It has been noted, but generally not appreciated, that commercially important materials display modest strength differentials near room temperature when deformed under quasi-static loading conditions at modest rates (~10-5 to 10-3 1/s). Under static loading, subtle variations in plastic flow behavior leads to dramatically weaker materials when loaded in tension versus compression. The asymmetric material responses of single and two-phase alloys deformed under monotonic constant rate and creep conditions have been investigated and related to the fundamental slip behavior observed in single crystalline materials. Two-phase titanium alloys containing a majority volume fraction of the alpha (HCP) phase have long been known to undergo creep deformation at lower temperatures (T
Microstructural and Mechanistic Study of Primary Creep in Titanium Alloys at Lower Temperatures
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Primary creep is a dominant mode of deformation for commercial, two-phase alpha-beta titanium alloys such as Ti-6242 which are used extensively in the fan and compressor sections of jet aircraft engines. This program has improved our understanding of the mechanisms and phenomenology of primary creep in these alloys. Using a phenomenological approach based on the Holomon equation, we have shown that the extensive low temperature creep behavior is linked to the exceptionally small values of strain hardening exponent exhibited by these alloys, and that the long term creep response can be predicted from the results of short-term, constant-strain rate tests. This insight has suggested possible processing paths for improving the creep response of these materials, including the minimization of short-range ordering. A second focus of the program has shown that the Widmanstatten colony structure exhibits a dramatic plastic anisotropy. Single colony crystals of Ti-5Al-2.5Sn-0.5Fe, were obtained in collaboration with J.M. Scott of UES and Wright Laboratory. Extensive TEM investigation has revealed that this anisotropy can be directly correlated with the transmission of dislocation across the beta laths, and the accumulation of residual dislocation content near the interfaces. This information is essential order to better model creep deformation in these materials.
The Effect of Grain Size and Stability on Ambient Temperature Tensile and Creep Deformation Behavior of Metastable Beta Titanium Alloys
Author: Durgalakshmi DoraiswamyPublisher:
ISBN:
Category :
Languages : en
Pages : 244
Book Description
Study of Ambient Temperature Compression Creep Deformation Behavior of Alpha Titanium Alloy
Author: Carl Andrew HultgrenPublisher:
ISBN:
Category :
Languages : en
Pages : 230
Book Description
First Quarterly Progress Report to materials laboratory, wright air development center department of the air force on intermediate temperature creep and rupture behavior of titanium and titanium alloys
Author: J. V. GluckA Review of the Low-temperature Creep Behaviour of Titanium
Author: Dutton, RPublisher: Pinawa, Man. : Whiteshell Laboratories
ISBN: 9780660166827
Category : Nuclear engineering
Languages : en
Pages : 51
Book Description