کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1599937 1515858 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of microstructure and C and Si additions on elevated temperature creep and fatigue of gamma TiAl alloys
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Effects of microstructure and C and Si additions on elevated temperature creep and fatigue of gamma TiAl alloys
چکیده انگلیسی
The creep properties of K5 (Ti-46Al-3Nb-2Cr-0.2W) based alloys were analyzed in wrought processed microstructure forms. The brittle-ductile-transition-temperature (BDTT) depends distinctly on microstructure as well as strain rate, with the minimum value for each microstructure achieved at ∼10−6/s being about 680 °C and 780 °C, respectively. The greatest creep resistance is achieved in coarse-grained fully lamellar (FL) material and is related to the strong anisotropy of lath structure, large grain size and consequently high BDTT. Additional significant resistance improvement is realized with additions or increases of refractory elements (Nb or W) and decrease in Al content. The most remarkable improvements in primary as well as the minimum creep resistance are realized when small amounts of C or C + Si are added to generate incoherent (to gamma) carbide and silicide particles along γ/γT interfaces. The significance of primary creep is assessed for controlling subsequent creep behavior and discussed for its crucial role in satisfying the stringent design creep requirements for advanced rotational components. The accelerated or tertiary creep is used to explain the high temperature (870 °C) high cycle fatigue deformation that exhibits two-stage SN curves with the rapidly softening second stage.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Intermetallics - Volume 53, October 2014, Pages 92-101
نویسندگان
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