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Author Khalil-Allafi, J.; Amin-Ahmadi, B.
Title The effect of chemical composition on enthalpy and entropy changes of martensitic transformations in binary NiTi shape memory alloys Type P3 Proceeding
Year 2009 Publication (up) Journal Of Alloys And Compounds Abbreviated Journal J Alloy Compd
Volume 487 Issue Pages 363-366
Keywords P3 Proceeding; Condensed Matter Theory (CMT)
Abstract In the present research work the binary NiTi alloys with various compositions in the range of 50.351 at.% Ni were used. Samples have been annealed at 850 °C for 15 min and then quenched in water. In order to characterize transformation temperatures and enthalpy changes of the forward and the reverse martensitic transformation, Differential Scanning Calorimetric (DSC) experiments were performed. The enthalpy and entropy changes as a function of Ni atomic content have been thermodynamically investigated. Results show that enthalpy and entropy changes of martensitic transformation decrease when Ni atomic content increases. The variation of enthalpy and entropy of martensitic transformation with Ni content in binary NiTi alloys were explained by thermodynamic parameters and electron concentration of alloy (e/a) respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000272521900073 Publication Date 2009-07-31
Series Editor Series Title Abbreviated Series Title Proceedings of the 22nd International Conference on the Physics of Semiconductors
Series Volume Series Issue Edition
ISSN 0925-8388; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.133 Times cited 30 Open Access
Notes Approved Most recent IF: 3.133; 2009 IF: 2.135
Call Number UA @ lucian @ c:irua:122040 Serial 804
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Author Khalil-Allafi, J.; Amin-Ahmadi, B.
Title Effect of mold hardness on microstructure and contraction porosity in ductile cast iron Type A1 Journal article
Year 2011 Publication (up) Journal of iron and steel research international Abbreviated Journal J Iron Steel Res Int
Volume 18 Issue 4 Pages 44-47
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The effect of mold hardness on the microstructure of ductile iron and the contraction porosity was investigated. Molds with different hardnesses (0.41, 0.48, 0.55, 0.62 MPa) and a sand mold prepared by Co2 method were used. The influence of silicon content on the induced expansion pressure owing to the formation of graphite was also investigated. The contraction during solidification can be compensated by an induced expansion owing to the graphite relief when the hardness of mold increases; therefore, the possibility of achieving a sound product without using any riser increases.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2011-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1006-706X; ISBN Additional Links UA library record
Impact Factor 0.836 Times cited 1 Open Access
Notes Approved Most recent IF: 0.836; 2011 IF: 0.213
Call Number UA @ lucian @ c:irua:122044 Serial 823
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Author Khalil-Allafi, J.; Amin-Ahmadi, B.
Title Influence of mold preheating and silicon content on microstructure and casting properties of ductile iron in permanent mold Type A1 Journal article
Year 2011 Publication (up) Journal of iron and steel research international Abbreviated Journal J Iron Steel Res Int
Volume 18 Issue 3 Pages 34-39
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The effects of the mold preheating and the silicon content of ductile iron on the percentage of carbides, graphite nodule counts and shrinkage volume were investigated. The results showed that the percentage of carbides and the shrinkage volume decreased when the mold preheating increased. The ductile iron with the carbon equivalent of 4.45% and the silicon content of 2.5% without any porosity defects was achieved when the mold preheating was 450 °C. Increasing the silicon content in the range of 2.1%3.3% led to the increase in graphite nodule count and graphite size and the decrease in percentage of carbides. It is due to the increase in induced expansion pressure during the graphite formation with the increasing of silicon content. The suitable condition for casting a sound product of ductile iron without the riser at the mold preheating temperature of 300 °C is the silicon content of 3.3% and carbon equivalent of 4.7%.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos Publication Date 2011-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1006-706X; ISBN Additional Links UA library record
Impact Factor 0.836 Times cited 3 Open Access
Notes Approved Most recent IF: 0.836; 2011 IF: 0.213
Call Number UA @ lucian @ c:irua:122043 Serial 1629
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Author Khalil-Allafi, J.; Amin-Ahmadi, B.
Title Multiple-step martensitic transformations in the Ni51Ti49 single crystal Type A1 Journal article
Year 2010 Publication (up) Journal of materials science Abbreviated Journal J Mater Sci
Volume 45 Issue 23 Pages 6440-6445
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Multiple-step martensitic transformations of an aged Ni51Ti49 single crystal using calorimetric method were investigated. Results show that for short aging times (1045 min) multiple-step martensitic transformations on cooling occur in two steps. Applying intermediate aging times (1.254 h) results in three steps and long aging times (more than 8 h) lead to two-step martensitic transformations again. This behavior has not been recognized in NiTi single crystals in literatures. It can be related to the heterogeneity of composition and stress fields around Ni4Ti3 precipitates.
Address
Corporate Author Thesis
Publisher Place of Publication London Editor
Language Wos 000282429400021 Publication Date 2010-06-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2461;1573-4803; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.599 Times cited 5 Open Access
Notes Approved Most recent IF: 2.599; 2010 IF: 1.859
Call Number UA @ lucian @ c:irua:122046 Serial 2231
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