LOW DENSITY AND HIGH STRENGTH NiTi MEMORY ALLOYS WITH CONTROLLABLE PORE CHARATERISTICS AND THEIR SUPERELASTICITY
LI Da-Sheng;yupeng zhang;zhipeng xiong;Xinping Zhang
华南理工大学机械工程学院
Cite this article:
LI Da-Sheng; yupeng zhang; zhipeng xiong; Xinping Zhang. LOW DENSITY AND HIGH STRENGTH NiTi MEMORY ALLOYS WITH CONTROLLABLE PORE CHARATERISTICS AND THEIR SUPERELASTICITY. Acta Metall Sin, 2008, 44(8): 995-1000 .
Abstract Low density and high strength NiTi shape memory alloys with regular pore shape and large pore size were fabricated by using temporary space-holder, CO(NH2)2, and a conventional sintering process. The pore characteristics can be tailored by adjusting urea particle features and the amount added, and the fabricated porous NiTi alloys show uniform pore size and regular pore shape with pore size and porosity in the ranges of 296-732 µm and 31%-61.6%, respectively. The results manifest that urea particle shape and size have a crucial influence on pore characteristics of porous alloys and show a geometrical heredity effect. The use of urea hardly has any effect on phase constituents of porous NiTi alloys and the martensitic transformation exhibits early. The fabricated porous NiTi alloys show excellent mechanical properties including a steady linear superelasticity.
[1]Itin V I,Gyunter V E,Shabalovskaya S A,Sachdeva R L C.Mater Charact,1994;32:179 [2]Kujala S,Ryhnen J,Danilov A,Tuukkanen J.Biomater, 2003;24:4691 [3]Li Y H,Rao G.B,Rong L J,Li Y Y,Ke W.Mater Sci Eng,2003;A363:356 [4]Kim J S,Kang J H,Kang S B,Yoon K S,Kwon Y S.Adv Eng Mater,2004;6:403 [5]Greiner C,Oppenheimer S M,Dunand D C.Acta Bio- mater,2005;1:705 [6]Zhang X P,Zhang Y P.Chin J Mater Res,2007;21:561 (张新平，张宇鹏．材料研究学报，2007；21：561) [7]Zhang Y P,Li D S,Zhang X P.Scr Mater,2007;57:1020 [8]Zhang Y P,Yuan B,Zeng M Q,Chung C Y,Zhang X P. J Mater Process Technol,2007;192-193:439 [9]Zhang X P,Zhang Y P,Chung C Y.Chin Pat. 200610124394.7,2006 (张新平，张宇鹏，钟志源．中国专利，200610124394．7，2006) [10]Zhang Y P,Zhang X P,Chung C Y.Acta Metall Sin,2007; 43:1221 (张宇鹏，张新平，钟志源．金属学报，2007；43：1221) [11]Zhang X P,Li D S,Zhang Y P,Chin Pat.200710030822.4, 2007 (张新平，李大圣，张宇鹏．中国发明专利，200710030822．4，2007) [12]ASTM.ASTM E9-89a,West Conshohocken,PA,2000 [13]Otsuka K,Wayman C M.Shape Memory Materials.Cam- bridge,UK:Cambridge University Press,1998:51 [14]Coluzzi B,Biocarini A,Campanella R,Mazzolai G,Trotta L,Mazzolai F M.J Alloys Compd,2000;310:300 [15]van Humbeeck J.J Alloys Compd,2003;355:58 [16]Li B Y,Rong L J,Li Y Y.Mater Sci Eng,2000;A281: 169 [17]Zhao Y,Taya M,Kang Y,Kawasaki A.Acta Mater,2005; 53:337 [18]Biswas A.Acta Mater,2005;53:1415 [19]Barrabés M,Sevilla P,Planell J A,Gil F J.Mater Sci Eng,2008;C28:23
