Creep of Al-Sc Microalloys with Rare-Earth Element Additions
نویسندگان
چکیده
Cast and aged Al-Sc microalloys are creep-resistant to 300, due to the blocking of dislocations by nanosize, coherent Al3Sc (L12) precipitates. Rare-earth elements substitute for Sc in these precipitates, leading to a higher number density of smaller precipitates, which have a greater lattice-parameter mismatch with Al than in the Al-Sc binary microalloy. This leads to an improvement in both ambient temperature microhardness and high temperature creep. Creep threshold stresses of Al-Sc-RE (RE = Y, Dy, or Er) at 300 are higher than for Al-Sc and Al-Sc-M (M = Mg, Ti, or Zr) microalloys. This is in agreement with a dislocation climb model that includes the elastic stress fields of the precipitates.
منابع مشابه
Mechanical Properties and Microstructure of Al – Sc with Rare - Earth Element or Al 2 O 3 Additions
Mechanical Properties and Microstructure of Al–Sc with Rare-Earth Element or Al2O3 Additions Richard Albert Karnesky, Jr. Aluminum alloys strengthened with coherent (L12), nanosize Al3Sc precipitates are structural materials that have outstanding strength at ambient and elevated temperatures. They are creep resistant at 300 ◦C and exhibit a threshold stress, below which creep is not measurable....
متن کاملDevelopment of a Nanoscale Precipitation-Strengthened Creep-Resistant Aluminum Alloy Containing Trialuminide Precipitates
Development of a Nanoscale Precipitation-Strengthened Creep-Resistant Aluminum Alloy Containing Trialuminide Precipitates Keith Edward Knipling This research is toward developing a castable andheat-treatable precipitation-strengthened aluminum alloy exhibiting coarseningand creep resistance at temperatures exceeding 400°C. Criteria for selecting alloying elements capable of producing such an al...
متن کاملEffects of Zr on the Microstructure and Mechanical Properties of Al-Sc- Yb Alloys
Cast, coarse-grained Al-Sc alloys are interesting candidates for high temperature, creepresistant applications due to the formation of a high number density of nanometer sized Al3Sc precipitates [1]. Upon addition of Yb to Al-Sc alloys, Yb replaces the Sc forming Al3(Sc1-xYbx) precipitates (L12 structure) [2]. The resulting alloys have higher creep resistance due to the larger lattice parameter...
متن کاملتوزیع عناصر کمیاب و خاکی نادر در میان فازهای دگرگونی و کلینوپیروکسن‌های باقیمانده در اپیدوت- آمفیبولیت‌های شمال ارومیه- شمال‌غرب ایران
Rare earth and trace element concentrations of mineral assemblages including amphibole, plagioclase, epidote group minerals (zoisite and clinozoisite) and relict clinopyroxenes from parental rock of epidote amphibolite from north of Urumia were obtained in situ by LA-ICP-MS analysis. The obtained data were used to study distribution of trace elements among metamorphic phases and relict clinopyr...
متن کاملTHERMAL ANALYSIS AND KINETICS OF THE PRECIPITATION IN WROUGHT Al-Mg, Al-Mg-ScAND Al-Mg-Sc-Me (Me=Zr, Ti) ALLOYS
Precipitation behaviour of wrought Al-6Mg alloys with ternary scandium and quaternary zirconium and titanium has been studied. Hardness measurements and resistivity studies are employed to assess the precipitation behaviour of scandium doped Al-6Mg alloy without or with quaternary additions of zirconium and titanium. Further, the kinetics of precipitations are studied by differential scanning c...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006