18 آبان 1403
حسين اسكندري

حسین اسکندری

مرتبه علمی: دانشیار
نشانی: دانشکده مهندسی - گروه مهندسی مکانیک
تحصیلات: دکترای تخصصی / مهندسی مواد
تلفن: 07731222153
دانشکده: دانشکده مهندسی

مشخصات پژوهش

عنوان Hardnessstrength relationships in fine and ultra-fine grained metals processed through constrained groove pressing
نوع پژوهش مقالات در نشریات
کلیدواژه‌ها
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مجله MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
شناسه DOI
پژوهشگران فرزاد خدابخشی (نفر اول) ، ر حق شناس (نفر دوم) ، حسین اسکندری (نفر سوم) ، م کوه بر (نفر چهارم)

چکیده

Fine grained (FG) and ultra-fine grained (UFG) materials processed by severe plastic deformation exhibit beneficial hardness and tensile properties. Constrained groove pressing (CGP) were employed for fabrication of FG and UFG sheet metals and accomplished into different types of metals and alloys, such as commercial pure aluminum, AA3003 aluminum alloy, commercial pure copper, nickel, titanium and low carbon steels. Tensile and hardness characteristics in the FG and UFG sheets have been assessed with the aim of evaluating the hardness?strength relationship frequently established for coarse-grained metals and alloys (?UTS/HV=3.45?UTS/HV=3.45). However, it was revealed that the FG and UFG materials do not obey widely used hardness?strength relationships in the conventional coarse grained structures. A new multiplicity factor less than 3, depending on the chemical composition of processed materials, is proposed in this study. This is attributed to different strain hardening response of the FG and UFG materials with slight work hardening before necking instability. In fine grained and ultra-fine grained structures failure does not occur in (or right after) the onset of necking point. That is, tensile deformation sustains significantly up to fracture point due to the role of superplasticity mechanisms.