THE MARTENSITIC-TRANSFORMATION IN TI-RICH TINI SHAPE-MEMORY ALLOYS

被引:65
作者
LIN, HC [1 ]
WU, SK [1 ]
LIN, JC [1 ]
机构
[1] NATL TAIWAN UNIV,INST MAT SCI & ENGN,TAIPEI 106,TAIWAN
关键词
D O I
10.1016/0254-0584(94)90091-4
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The martensitic (Ms) transformation temperatures and their DELTAH values of Ti51Ni49 and Ti50.5Ni49.5, alloys are higher than those of equiatomic or Ni-rich TiNi alloys. The Ti-rich TiNi alloys exhibit good shape recovery in spite of a great deal of second phase Ti2Ni or Ti4Ni2O existing around B2 grain boundaries. The nearly identical transformation temperatures indicate that the absorbed oxygen in Ti-rich TiNi alloys may react with Ti2Ni particles, instead of the TiNi matrix, to form Ti4Ni2O. Martensite stabilization can be induced by cold rolling at room temperature. Thermal cycling can depress the transformation temperatures significantly, especially in the initial 20 cycles. The R-phase transformation can be promoted by both cold rolling and thermal cycling in Ti-rich TiNi alloys due to introduced dislocations depressing the Ms temperature. The strengthening effects of cold rolling and thermal cycling on the Ms temperature of Ti-rich TiNi alloys are found to follow the expression Ms = To - KDELTAsigma(y). The K values are affected by different strengthening processes and related to the as-annealed transformation temperatures. The higher the as-annealed Ms (or As), the larger the K value.
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页码:184 / 190
页数:7
相关论文
共 34 条
[11]   DETERMINATION OF HEAT OF TRANSFORMATION IN A COLD-ROLLED MARTENSITIC TINI ALLOY [J].
LIN, HC ;
WU, SK .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1993, 24 (02) :293-299
[12]  
LIN HC, 1991, ACTA METALL MATER, V39, P2609
[13]  
LIN JC, 1991, THESIS NATIONAL TAIW
[14]  
LING HC, 1981, METALL T A, V12, P2102
[15]  
LO YC, 1992, THESIS TAIPEI TAIWAN
[16]  
Melton K, 1990, ENG ASPECTS SHAPE ME, V344, P21
[17]   LOW-FREQUENCY INTERNAL-FRICTION PEAKS ASSOCIATED WITH THE MARTENSITIC PHASE-TRANSFORMATION OF NITI [J].
MERCIER, O ;
MELTON, KN ;
DEPREVILLE, Y .
ACTA METALLURGICA, 1979, 27 (09) :1467-1475
[18]   EFFECT OF THERMAL CYCLING ON THE TRANSFORMATION TEMPERATURES OF TI-NI ALLOYS [J].
MIYAZAKI, S ;
IGO, Y ;
OTSUKA, K .
ACTA METALLURGICA, 1986, 34 (10) :2045-2051
[19]   EFFECT OF CYCLIC DEFORMATION ON THE PSEUDOELASTICITY CHARACTERISTICS OF TI-NI ALLOYS [J].
MIYAZAKI, S ;
IMAI, T ;
IGO, Y ;
OTSUKA, K .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1986, 17 (01) :115-120
[20]   CHARACTERISTICS OF DEFORMATION AND TRANSFORMATION PSEUDOELASTICITY IN TI-NI ALLOYS [J].
MIYAZAKI, S ;
OHMI, Y ;
OTSUKA, K ;
SUZUKI, Y .
JOURNAL DE PHYSIQUE, 1982, 43 (NC-4) :255-260