The effect of austenite aging at 823 K on the microstructures and martensitic transformation behavior of Co46Ni27Ga27 alloy has been investigated using optical microscopy (OM),transmission electron microscopy (TEM),X-ray diffraction analysis (XRD),and differential scanning calorimeter (DSC).The microstructure observation results show that the unaged Co46Ni27Ga27 alloy is composed of the tetragonal nonmodulated martensite phase and face-centered cubic γ phase.It is found that a new nanosized fcc phase precipitates in the process of austenite aging,leading to the formation of metastable age-affected martensite around the precipitates with composition inhomogeneity.Two-stage reverse martensitic transformation occurs in the samples aged for 2 and 24 h due to the composition difference between the age-affected martensite and the original martensite.For the Co46Ni27Ga27 alloy aged for 120 h,no reverse transformation can be detected due to the disappearance of the metastable age-affected martensite and the small latent heat of the original martensite.The martensitic transformation temperatures of the Co46Ni27Ga27 alloy decrease with an increase in aging time.
参考文献
[1] | Otsuka K;Wayman C.M.Shape Memory Materials[M].Cambridge:Cambridge University Press,1998:220. |
[2] | Zhao L.C;Cai W;Zheng Y.F.Shape Memory Effect and Superelasticity in Alloys[M].北京:国防工业出版社,2002:5. |
[3] | Yang J.H;Wayman C.M .On the formation mechanism of Ni5Al3 in NiAl-base alloys:Part Ⅰ.Microstructures[J].Intermetallics,1994,2(02):111. |
[4] | Golberg D;Xu Y;Murakami Y;Otsuka K and Ueki T .High temperature shape memory effect in Ti50Pd50-xNix (x =10,15,20) alloys[J].Materials Letters,1995,22(05):241. |
[5] | Bigelow G.S;Padula S.A;Garg A;Padula Ⅱ S.A Garg A and Noebe R.D .Correlation between mechanical behavior and actuator-type performance of Ni-Ti-Pd high-temperature shape memory alloys[J].Proceedings of Spie,2007,6526:65262B. |
[6] | Tong Y.X;Chen F;Tian B;Li L and Zheng Y.F .Microstrucrare and martensitic transformation of Ti49Ni51-xHfx high temperature shape memory alloys[J].Materials Letters,2009,63(21):1869. |
[7] | Xu H.B .Cu-based high-temperature shape-memory alloys and their thermal stability[J].Materials Science Forum,2002,394-395:375. |
[8] | Firstov G.S;Humbeeck J.V;Koval Y.N .High-temperature shape memory alloys some recent developments[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2004,378(1-2):2. |
[9] | He Z.R;Zhou J.E;Furuya Y .Effect of Ta content on martensitic transformation behavior of RuTa ultrahigh temperature shape memory alloys[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2003,348(1-2):36. |
[10] | Xu H.B;Li Y;Jiang C.B .Ni-Mn-Ga high-temperature shape memory alloys[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2006,438-440:1065. |
[11] | Corneliu Craciunescu;Yoichi Kishi;T. A. Lograsso;Manfred Wuttig .Martensitic transformation in Co_2NiGa ferromagnetic shape memory alloys[J].Scripta materialia,2002(4):285-288. |
[12] | Chemenko V.A;Pons J;Cesari E;Perekos A.E .Martensitic transformation in a ferromagnetic Co-Ni-Ga single crystal[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2004,378(1-2):357. |
[13] | J. Dadda;H. J. Maier;I. Karaman .Pseudoelasticity at elevated temperatures in [0 0 1] oriented Co_(49)Ni_(21)Ga_(30) single crystals under compression[J].Scripta materialia,2006(8):663-666. |
[14] | Liu J;Xie H;Huo Y.Q;Zheng H.X and Li J.G .Microstructure evolution in CoNiGa shape memory alloys[J].Journal of Alloys and Compounds,2006,420(1-2):145. |
[15] | Liu J;Zheng H.X;Xia M.X;Huang Y.L and Li J.G .Martensitic transformation and magnetic properties in Heusler CoNiGa magnetic shape memory alloys[J].Scripta Materialia,2005,52(05):935. |
[16] | Yan Li;Yan Xin;Liang Chai .Microstructures and shape memory characteristics of dual-phase Co-Ni-Ga high-temperature shape memory alloys[J].Acta materialia,2010(10):3655-3663. |
[17] | J. Khalil Allafi;X. Ren;G. Eggeler .The mechanism of multistage martensitic transformations in aged Ni-rich NiTi shape memory alloys[J].Acta materialia,2002(4):793-803. |
[18] | Segui C;Cesari E;Font J;Muntasell J;Chernenko VA .Martensite stabilization in a high temperature Ni-Mn-Ga alloy[J].Scripta materialia,2005(3):315-318. |
[19] | Khovailo V.V;Kainuma R;Abe T;Oikawa K and Takagi T .Aging-induced complex transformation behavior of martensite in Ni57.5Mn17.5Ga25 shape memory alloy[J].Scripta Materialia,2004,51(04):13. |
[20] | Yan Xin;Yan Li;Liang Chai .The Effect of Aging on the Ni-Mn-Ga High-Temperature Shape Memory Alloys[J].Scripta materialia,2006(6):1139-1143. |
[21] | Chen J;Li Y;Shang JX;Xu HB .The effects of alloying elements Al and In on Ni-Mn-Ga shape memory alloys, from first principles[J].Journal of Physics. Condensed Matter,2009(4):045506-1-045506-7-0. |
- 下载量()
- 访问量()
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%