Study of superplasticity in Pb-Sn eutectic alloy using impression creep technique

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Impression creep method has been used to study the creep behaviour of Pb-Sn eutectic alloy of two different grain sizes, viz., 3.4 and 7.5 <i style="mso-bidi-font-style:normal">µ</i>m in the temperature range of 30-125°C. The deformation response of the fine grained material conformed to regions II and III of a typical sigmoidal behaviour of a superplastic material. The strain rate sensitivity index values determined for region II, 0.43-0.55, were also indicative of superplastic behaviour. In coarse grained material, superplastic behaviour was seen only at higher test temperatures. These showed lower values of strain rate sensitivity index, namely 0.21-0.45. It is concluded that the impression creep technique is attractive for characterising superplasticity when only a small volume of material is available.</span>