نتایج جستجو برای: tial
تعداد نتایج: 1703 فیلتر نتایج به سال:
In two-phase TiAl-based alloys, the coexisting 2 and phases exhibit a thermal expansion mismatch, so that increased creep rates during thermal cycling may be expected. Creep deformation of two g-TiAl-based alloys was investigated during thermal cycles between 900 and 300 or 350 C with applied tensile stresses of 32.5 or 37.0 MPa. Measured thermal cycling creep rates were compared with isotherma...
This is a screening study using high-energy X-ray diffraction measurements to determine whether an orthorhombic phase forms in ?-based TiAl alloys of different compositions. The 13 alloy compositions investigated were chosen be either close commercial or identify the effects single alloying elements on formation phase. O with Cmcm structure was found several those ?-TiAl after aging heat treatm...
Preparing high relative density ?-TiAl alloy by pressure-less sintering at low-cost has always been a challenge. Therefore, new kind of non-spherical pre-alloyed TiAl powder was prepared the reaction TiH2 and Al 800 °C to fabricate high-density Ti-48Al via sintering. The oxygen content controlled below 1800 ppm using coarse (~120 ?m). sintered densities ranged from 92.1% 97.5% with temperature ...
To modify the microstructure and enhance performances, the ultrasonic vibration is applied in the mould casting of TiAl alloy. The effects and mechanism of ultrasonic vibration on the solidifying microstructure and mechanical properties are investigated and the model for predicting lamellar colony size is established. After ultrasonic vibration, the coarse microstructure is well modified and la...
در این تحقیق یک پوشش آلومیناید نیکلی به وسیله? آبکاری اولیه? یک لایه نیکل بر روی آلیاژ ?-tial و به دنبال آن انجام فرایند آلومینایزینگ اکتیویته بالا به روش تک-مرحله ای ایجاد شده است. جلوه های میکروساختاری مختلف پوشش آلومیناید نیکلی مورد مطالعه قرار گرفته است و تاثیر مقدار نیکل بر میکروساختار پوشش آلومیناید نیکلی تولید شده با فرایند آلومینایزینگ اکتیویته-بالا به روش تک-مرحله ای بررسی شده است. پوش...
High temperature plastic flow properties of two phase TiAl alloys containing 45 to 49 at.%Al have been investigated in thermo-mechanically grain refined materials in order to clarify the favourable microstructure and chemical composition for TiAl based superplastic materials. Grain sizes of thermomechanical treated materials and their grain size stability during subsequent high temperature defo...
Abstract In this research the oxidation resistance at high temperature of a TiAl-based alloy has been improved by hot-dipping in molten aluminium and performing an interdiffusion process. After selecting best process parameters, compact TiAl 3 coating characterized almost constant thickness was formed on surface. Isothermal tests, carried out 900, 950 1000 °C, showed that coated is able to form...
ترکیبات آلومینایدهای تیتانیوم به این دلیل که ویژگیهای حرارتی آلیاژهای پایه تیتانیوم را توسعه دادهاند، جذابیت فراوانی دارند. باوجود داکتیلیتة کمتر این دسته از مواد نسبت به آلیاژهای متداول پایه تیتانیوم، این ترکیبات گپ و خلأ موجود در قابلیت عملکردی مواد سبک وزن در محدودة دمایی 500 تا 700 درجة سانتیگراد را پر کردهاند. آلیاژهای آلومیناید تیتانیوم براساس فازهای بینفلزی γ (TiAl) و α...
A sufficiently general thermally activated mechanism for extension of dislocations in some preferential direction was proposed. This mechanism comprises a necessary step of dislocation transformations that lead to blocking. The reasons for blocking of different types of dislocations in different materials are diverse. A new concept was developed concerning the possibility of thermally activated...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید