Effects of Combined Additions of Al, Be, and Ti on Precipitation Hardening of Fe-Ni Alloys

Precipitation Hardening of Al–Si–Mg Alloys

the effects of planning on accuracy and complexity of iranian efl students’ written narrative task performance

this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...

the effects of time planning and task complexity on accuracy of narrative task performance

هدف اصلی این تحقیق بررسی تاثیر برنامه ریزی زمانی، هم چنین افزایش میزان پیچیدگی تکالیف در نظر گرفته شده بصورت همزمان، بر دقت و صحت و پیچیدگی عملکرد نوشتاری زبان آموزان می باشد. بدین منظور، 50 نفر از دانش آموزان دختر در رده ی سنی 16 الی 18 سال به عنوان شرکت کنندگان در این زمینه ی تحقیق در نظر گرفته شدند و به دو گروه آزمایشی و کنترل بصورت اتفاقی تقسیم شدند. اعضای گروه آزمایشی هر دو تکلیف ساده و پی...

Effects of Li additions on precipitation-strengthened Al–Sc and Al–Sc–Yb alloys

Two Al–Sc-based alloys (Al–0.12Sc and Al–0.042Sc–0.009Yb, at.%) and their counterparts with Li additions (Al–2.9Li–0.11Sc and Al–5.53Li–0.048Sc–0.009Yb, at.%) are aged at 325 C. For both base alloys, the addition of Li results in greater peak hardness from incorporation of Li in the L12-structured a-Al3(Sc,Li) and a-Al3(Sc,Li,Yb) precipitates, and a concomitant increase in number density and vo...

Precipitation hardening in dilute Al–Zr alloys

The aim of this study was to investigate the effect of solute content (hipoperitectic Al–0.22 wt.%Zr and hiperperitectic Al–0.32 wt.%Zr) on the precipitation hardening and microstructural evolution of dilute Al–Zr alloys isothermally aged. The materials were conventionally cast in a muffle furnace, solidified in a water-cooled Cu mold and subsequently heat-treated at the temperature of 650 K (3...