چکیده مقاله
NiTiHf alloys are known as one of the most promising groups of shape memory alloys for operating at temperatures above 100 ºC In this paper, effect of intermediate aging on the microstructure, transformation temperatures, and one way shape memory behavior of a Ni49Ti36Hf15 alloy was investigated For this purpose, an ingot was fabricated using vacuum induction melting of high purity Ni, Ti, and Hf precursors The alloy was then homogenized at 1000 ºC, hot rolled at 850 ºC, and solution treated at 1000 ºC, respectively, to be prepared for aging treatment Aging treatment was carried out at 500 ºC and 600 ºC for 2h OM, SEM, XRD, DSC, and the so called bending test were used to characterize the alloy Results demonstrated that microstructure of the aged Ni49Ti36Hf15 is composed of B19’ martensitic matrix, Ti,Hf 2Ni second phase mostly at grain boundary regions, and a new phase, while an approximately 25 ºC decrease in transformation temperatures was observed after aging It was also found that this heat treatment cannot provide better shape memory properties for the alloy That aging provided no improvement was correlated to the microstructure of the alloy
کلیدواژهها
نویسندگان
M Moshref-Javadi
School of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran, Iran
M Belbasi
School of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran, Iran
S. H. Seyedein
School of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran, Iran
M. T. Salehi
School of Materials & Metallurgical Engineering, Iran University of Science & Technology, Tehran, Iran
شیوه ارجاع
Moshref-Javadi, M and Belbasi, M and Seyedein, S. H. and Salehi, M. T.,1390,Heat Treatment of a (Ti,Hf)-Rich NiTiHf High Temperature Shape Memory Alloy,12th Iranian Conference on Manufacturing Engineering (ICME 2010),Tehran
ارائهشده در
مجموعه مقالات دوازدهمین کنفرانس ملی مهندسی ساخت و تولید ایران6 دی 1390 · تهران