Received: from mx02.ecn.purdue.edu (mx02.ecn.purdue.edu [128.46.177.8]) by mailbag.ecn.purdue.edu (8.14.4/8.14.4) with ESMTP id q4BIQjkW023841 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 11 May 2012 14:26:45 -0400 (EDT) Received: from mailhub128.itcs.purdue.edu (mailhub128.itcs.purdue.edu [128.210.5.128]) by mx02.ecn.purdue.edu (8.14.4/8.14.4) with ESMTP id q4BIQ2pJ006735 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Fri, 11 May 2012 14:26:02 -0400 Received: from WPPEXHUB01F.purdue.lcl (wppexhub01f.itap.purdue.edu [172.21.6.90]) by mailhub128.itcs.purdue.edu (8.14.4/8.14.4/mta-nopmx.smtp.purdue.edu) with ESMTP id q4BIQ1lU018136; Fri, 11 May 2012 14:26:01 -0400 Received: from VPEXCH02.purdue.lcl ([169.254.2.132]) by WPPEXHUB01F.purdue.lcl ([::1]) with mapi; Fri, 11 May 2012 14:26:01 -0400 From: "Stacey, Lisa A" To: "'msefaculty-list@ecn.purdue.edu'" , "'msegradstudent-list@ecn.purdue.edu'" , "'msepostdoc-list@ecn.purdue.edu'" Date: Fri, 11 May 2012 14:26:00 -0400 Subject: Seminar Notice - K. Chaput Thur. May 17 Thread-Topic: Seminar Notice - K. Chaput Thur. May 17 Thread-Index: Ac0vo4LCO5DxcjAKRIqmE+E8LT4wvA== Message-ID: <92F872D971E7AA498CF64DD847E5594D89C36E8411@VPEXCH02.purdue.lcl> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: yes X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/related; boundary="_004_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_"; type="multipart/alternative" MIME-Version: 1.0 X-PMX-Version: 5.5.9.388399 X-PerlMx-Virus-Scanned: Yes X-ECN-MailServer-VirusScanned: by amavisd-new X-ECN-MailServer-Origination: mailhub128.itcs.purdue.edu [128.210.5.128] X-ECN-MailServer-SpamScanAdvice: DoNotScan --_004_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_ Content-Type: multipart/alternative; boundary="_000_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_" --_000_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MATERIALS SCIENCE AND ENGINEERING SEMINAR Effect of Biomodal Grain Distribution on Severely Plastically Deformed Copp= er by Kevin Chaput Purdue MSE Prelim 1 Advisor: Professor K. Trumble ABSTRACT In recent years there has been a demand for research in the area of ultra-f= ine grained (UFG) materials. The superior strength of these materials is d= ue to the Hall-Petch strengthening provided by ultra-fine grains has led to= a drive to further understand this process and the other properties of thi= s unique processing method. One of the most important material property tr= ade-offs is strength vs. ductility. With the relatively high strength of U= FG materials the poor ductility is expected since the mechanisms that cause= high strength usually lead to poor ductility. For these materials to ever= be used commercially a higher ductility in these materials must be achieve= d. While there have been a few proposed mechanisms to achieve this= property the most promising path has been in the creation of a multi-scale= grain distribution. The bi-modal and multi-modal grain distribution can be= produced through either secondary recrystallization or particle consolidat= ion. The resulting microstructure will be a mixture of typical coarse grai= ns and UFG grains. The basic idea behind this process is that the fine gra= ins will act as effective strengthening mechanism while the larger grains a= llow for increased area for the dislocations to interact and strain harden = the material which due to Considere's criterion prolongs, the onset of neck= ing. The effectiveness of this mechanism and the resulting properties will= be the primary area that will be under investigation. There is some conflict in the properties of the multi-scale mic= rostructures that vary between bi-modal and multimodal as well as between i= nvestigators. While the general consensus is that this procedure increases= the ductility it is important to notice the resulting effect has on the st= rength since that is the primary strength of this property. While most inv= estigators believe that the material's ratio of strength to ductility is ty= pical for alloy or metal it is made of, some experimenters, Wang et. al., h= ave published some results that show an increased ratio which is an excitin= g possibility for these materials. To do a thorough investigation into the engineering possibiliti= es that can come from this a complete understanding into what aspect of the= ductility is important. While for production and processing of metals the= traditional definition of ductility is important this definition for struc= tural applications will not suffice. The amount of plastic deformation bef= ore fracture is important for processes like extrusion and deep drawing but= for structural applications the onset of necking displays the highest stre= ngth that can be sustained before failure of the part so this will be far m= ore important and this will be taken into consideration when ductility valu= es are reported. Date: Thursday, May 17, 2012 Time: 9:00 AM Place: ARMS Rm. 1021 Lisa Stacey Secretary/Development Assistant Purdue University School of Materials Engineering 765/494-4100 --_000_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable = <= meta name=3DGenerator content=3D"Microsoft Word 12 (filtered medium)">

MATERIALS SCIENCE AND ENGINEERIN= G

<= span style=3D'font-size:14.0pt;font-family:"Times New Roman","serif"'>SEMIN= AR

 

Effect of Biomodal Grain D= istribution on Severely Plastically Deformed Copper

 

by

 

Kevin Chaput

Purdue MSE Prelim 1

Advisor:  Prof= essor K. Trumble

 

ABSTRACT

 

In recent years there has been a = demand for research in the area of ultra-fine grained (UFG) materials. = ; The superior strength of these materials is due to the Hall-Petch strengt= hening provided by ultra-fine grains has led to a drive to further understa= nd this process and the other properties of this unique processing method.&= nbsp; One of the most important material property trade-offs is strength vs= . ductility.  With the relatively high strength of UFG materials the p= oor ductility is expected since the mechanisms that cause high strength usu= ally lead to poor ductility.  For these materials to ever be used comm= ercially a higher ductility in these materials must be achieved.

       &= nbsp;    While there have been a few proposed mechanisms to = achieve this property the most promising path has been in the creation of a= multi-scale grain distribution. The bi-modal and multi-modal grain distrib= ution can be produced through either secondary recrystallization or particl= e consolidation.  The resulting microstructure will be a mixture of ty= pical coarse grains and UFG grains.  The basic idea behind this proces= s is that the fine grains will act as effective strengthening mechanism whi= le the larger grains allow for increased area for the dislocations to inter= act and strain harden the material which due to Considere’s criterion= prolongs, the onset of necking.  The effectiveness of this mechanism = and the resulting properties will be the primary area that will be under in= vestigation.

   &n= bsp;        There is some conflict in th= e properties of the multi-scale microstructures that vary between bi-modal = and multimodal as well as between investigators.  While the general co= nsensus is that this procedure increases the ductility it is important to n= otice the resulting effect has on the strength since that is the primary st= rength of this property.  While most investigators believe that the ma= terial’s ratio of strength to ductility is typical for alloy or metal= it is made of, some experimenters, Wang et. al., have published some resul= ts that show an increased ratio which is an exciting possibility for these = materials.

   &nbs= p;        To do a thorough investigation= into the engineering possibilities that can come from this a complete unde= rstanding into what aspect of the ductility is important.  While for p= roduction and processing of metals the traditional definition of ductility = is important this definition for structural applications will not suffice.&= nbsp; The amount of plastic deformation before fracture is important for pr= ocesses like extrusion and deep drawing but for structural applications the= onset of necking displays the highest strength that can be sustained befor= e failure of the part so this will be far more important and this will be t= aken into consideration when ductility values are reported.

 

Date:       Thursday, May 17, 2012<= /o:p>

Time:      9:00 AM

 

 

 

Lisa Stacey

Secretary/Development Assistant=

Purdue University=

School of Materials Enginee= ring

765/494-4100<= /o:p>

 

= --_000_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_-- --_004_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_ Content-Type: image/gif; name="image001.gif" Content-Description: image001.gif Content-Disposition: inline; filename="image001.gif"; size=2051; creation-date="Fri, 11 May 2012 14:18:05 GMT"; modification-date="Fri, 11 May 2012 14:18:05 GMT" Content-ID: Content-Transfer-Encoding: base64 R0lGODlhuAsQAPcAAP///uLNMf/+/P///eTQPf7++/7++v388v799+7iiOTRQP79+eXRQ/r22Pj0 z/bwwOfWVPr11u/kkPfyxeLOM+fVUvjzzO7hhvTts/jzzfLnn+LPNvPrrv389PXuuvz66PTtsf79 +P/+/fXvvfv44/799fz77ePQOu/ii/377+3hf/Loovv43/HmmOrbbObVT/Dlk+vdc+naZ/n00+jX W/bwvufWV+fUUOrbau7hgu3hhOnaZv799vr22/n11+/kj/fyx/j00fPrrPfwwuXSSezfefLnnuvb bunZYunYYPz77uvdceXSRf388/fyyerZZPPqquvedPXut/buu/XttvTssPLppO3gfuLONeXTSvr2 2uzed/z66fv44vDllOPPOOLPOOfWVf388O3fe+PNMu/jjfr33vn11ObUTffzyvfwxPv34fz67Pz6 6/v55vLmm/HnmvPppfz55+TSQeXSR/7++fr33ejXXvLqp+fXWv///wAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACwAAAAAuAsQAAAI/gADCAxA hgKWDV/AnCBAQMEcBkzoEMmC5sWNChDC2MhD404SJE92yMDh4siSGFG2FBlzRUUOHRcSoCjzQwIM Ly3gvDGiYYWVOHigCOFQBQQGKlI8TBlR48EQNROAOEljIYODIDPORPDRQEsPO2ZYrOlCwo2cD1za sDGhJIWYAweadCjBAwGCEAvqGDBQoICAvyIGDABAuLCew4gTK17MuLHjx5AjS55MubLly5gza97M ubPnz6BDix5NurTp06hTq17NurXr17Bjy55Nu7bt27hz697Nu7fv38CDCx9OvLjx48iTK1/OvLnz 59AjDyRoEKFChg4hSqRoEaNGjh5B/ookaRKlSpYuYcqkaROnTp4+gQolahSpUqZOoUqlahWrVq5e gSUWWWahpRZbbsElF1124aUXX34BJlhhhkVn4YUYZqjhhhx26OGHIIYo4ogklmjiiSimqOKKLLbo 4oswxijjjK1NV9BBCS3U0EMRTVTRRRlt1NFHIY1U0kkprdTSSzHNVNNNOe3U009BDVXUUUkt1dRT UU1V1VVZbdXVV2GNVdZZaa3V1ltxzVXXXXnt1ddfAgQ2GIUA0Kjnnnz26eefgAYq6KCEFmrooYgm quiijDbq6KOQXmZjdTlix+N2P3onZHhFkofkeUuq52R7UcJH5XxX2qdlfl3yB+Z//mMKaGaBaSLI 5oJvOihnhHVOiGekwAYr7LDEFmvsscgmq+yyzDbr7LPQRittbpPieN2O2vnYXZDgETnekeYpmV6T 7EH53pTyWVlflvhxud+X/okZYJkEonngmgq62WCcENJpJ555TivwwAQXbPDBCCes8MIMN+zwwxBH jHC11umYXY/cAfndkOIZWV6S6DG53pPuSRlflfRhed+W+nnZX5gAkjngmQaqmWCbDML54JwS3kmh xEAHLfTQRBdt9NFIJ6300kw37fRuFFeKLcaZcstxp+CCHCq5JJeKLsqpsstyq/DCHCu9NNeKL865 8stzrz5X+PTcdNdt99145633/t589+3333tHfe3FmG67MafffgzquCOTeu7JqK67MqvvvgzrvDPT eu/NuO67M6///gr46KSXbvrpqKeu+uqst+5664JbfKm2Gm/qrcefiivyqOaafKq6Kq/qrsuvyivz rPbafKu+Ou/qr68/vy799NRXb/312Gev/fbcd1/jQDdWbGm2GWvabceehhuyqOWWbGq6Kavabsuu xhuzrPXWbGu+Oevab88A854AB0jAAhrwgAhMoAIXyEA9xW58VDOc7dCXtcXtrn1egxzw5De2yhXv fmjTnPL417bPPS9uhGmgClfIwha68IUwjKEMZ/i6B06tcLU7H9YUpzv2de1x7L+Ln9goRzz7nS1z ydsf2zznPACKjoZQjKIUp0jFKlrxiljMYohsSDjame9qicvd+rjmON/BL2yTG179zIY55OlvbZ1r 3v/gFkAt2vGOeMyjHvfIxz76sYFcnF35rIY43Klva43r3fvAJjnh0a9slzte/tTGOeb5722hi94f N8nJTnryk6AMpShHOaxAkq9qh7td+rTGON6572uRC978yGY54+EvbZtbXv/cBjroyY2UwAymMIdJ zGIa85jIPI0pI5hDMBqSlRf8oRkZKcsOFpGNksTlCJcoR0z6MoXJDKc4x0nOcprznOhUYEAAADs= --_004_92F872D971E7AA498CF64DD847E5594D89C36E8411VPEXCH02purdu_--