scholarly journals Investigation of shape recovery stress for ferrous shape memory alloy

2009 ◽  
Author(s):  
H. Naoi ◽  
M. Wada ◽  
T. Koike ◽  
H. Yamamoto ◽  
T. Maruyama
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Recovery ◽  
Recovery Stress ◽  
Ferrous Shape Memory Alloy

Shape Recovery Characteristics of Pipes With Heavy Wall Thickness Made by Ferrous Shape Memory Alloy

2004 ◽  
Author(s):  
Yoshinori Joto ◽  
Manabu Wada ◽  
Hisashi Naoi ◽  
Tadakatsu Maruyama
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Wall Thickness ◽  
Shape Recovery ◽  
Chemical Compositions ◽  
Test Machine ◽  
Core Tube ◽  
Recovery Strain ◽  
Ferrous Shape Memory Alloy

Recently, ferrous shape memory alloys have been developed. Shape recovery strains of ferrous shape memory alloys are smaller than those of Ti-Ni shape memory alloys[1,2]. Strength, ductility and workability of the former alloy are higher than those of the latter alloy. Therefore, ferrous shape memory alloys are tried to apply for several kinds of pipe joints, as an example, joints of support pipes in the tunnel[3]. One of the other applications, the alloys is used as the material of simulation model to analyze the deformation behavior of the core tube in the fast breeder reactor. In this study, we investigated the shape recovery characteristics of pipes with heavy wall thickness made by ferrous shape memory alloy. Chemical compositions of this alloy are Fe, 28%Mn, 6%Si and 5%Cr. The alloy is melted, and round bars are manufactured by rolling, and pipes are machined from them. Tensile strength is 1100MPa, and yield strength is 320MPa. Ratios of wall thickness to central diameter of pipes are 10, 15, 20 and 25%. We insert tapered punch in the pipe, and expanded it by test machine. Then the circumferential strain of the center diameter of the pipes is 7%. And finally, the heat treatment is conducted at 350 degrees C in order to induce the shape recovery strain, and the pipe diameter decreases by means of austenitic transformation. The results obtained by the experiment are shown as follows. As the value of ratios of wall thickness to center diameter decreases, shape recovery strain increases and seems to approach the shape recovery strain obtained by uni-axial tension test, which was conducted in the past time.

Investigation of Shape Recovery Characteristics on Ferrous Shape Memory Alloy

2003 ◽  
Author(s):  
Manabu Wada ◽  
Hisashi Naoi ◽  
Kazuyuki Tsukimori
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Recovery ◽  
Heating Process ◽  
Training Process ◽  
Work Strain ◽  
Cubic Equation ◽  
Recovery Strain ◽  
Ε Martensite ◽  
Ferrous Shape Memory Alloy

Aims of this study are to clarify the shape recovery characteristics on ferrous shape memory alloy in order to utilize one as a many kinds of mechanical components. In this study, Fe-Mn-Si-Cr shape memory alloy is used. The fundamental characteristics and the shape recovery characteristics are investigated in this alloy. From the result of this investigation, shape recovery strain without training process reaches to maximum value of 2% at the amount of 5∼7% work-strain. That with the training process reaches 3.5% in the maximum, which is 1.8 times of that without training process. In addition, the shape recovery characteristic under constant stress which is given during the heating process is investigated. The microstructure of the deformed material is observed. The Widmanstatten structure is generated. This structure is attributed to the transformation from austenite to ε-martensite. In order to enable the prediction analysis of the shape recovery behavior, the relationship between shape recovery strain and work-strain is formulated by the regression analysis in cubic equation.

Effects of Mechanical Treatment and Pre-Deformation on Shape Recovery Stress of Ti50Ni47Fe3 Shape Memory Alloy

2014 ◽  
Vol 787 ◽  
pp. 267-274 ◽  
Author(s):  
Yu Zhang ◽  
Fu Shun Liu
Keyword(s):  
Shape Memory ◽  
Hot Rolling ◽  
Deformation Temperature ◽  
Mechanical Treatment ◽  
Shape Recovery ◽  
Hot Forging ◽  
Recovery Stress ◽  
Area Reduction ◽  
Rate Of Recovery ◽  
Rolling Deformation

Effects of mechanical treatment, pre-strain and pre-deformation temperature on shape recovery stress of Ti50Ni47Fe3 shape memory alloys were investigated. Mechanical treatment, consisting of hot-rolling and hot-forging, improved σrmax σrmax (maximum recovery stress), dσr/dT (rate of recovery stress with temperature) and Ts (the temperature at which recovery stress rises sharply). Martensitic transformation and reverse transformation temperatures also increased with increasing the hot-rolling deformation. σrmax and dσr/dT increased with increasing pre-strain at first and then decreased with further increasing of pre-strain, and the maximum values of σrmaxand dσr/dT were obtained at a pre-strain of 10%. On the other hand, σrmaxand dσr/dT decreased with increasing pre-deformation temperature. Upon a hot-rolling of 88% area reduction and pre-deformation of 10% at-150°C, the Ti50Ni47Fe3 alloy exhibited excellent recovery stress property with the σrmax of 391MPa in combination with dσr/dT of 5.09.

scholarly journals The Instability Improvement of the Symmetric Angle-Ply and Cross-Ply Composite Plates with Shape Memory Alloy Using Finite Element Method

2014 ◽  
Vol 6 ◽  
pp. 632825 ◽  
Author(s):  
Zainudin A. Rasid ◽  
Rizal Zahari ◽  
Amran Ayob
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Volume Fraction ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Element Formulation ◽  
Recovery Stress ◽  
Buckling Behavior ◽  
Post Buckling

Shape memory alloy (SMA) wires were embedded within laminated composite plates to take advantage of the shape memory effect property of the SMA in improving post-buckling behavior of composite plates. A nonlinear finite element formulation was developed for this study. The plate-bending formulation used in this study was developed based on the first order shear deformation theory, where the von Karman's nonlinear moderate strain terms were added to the strain equations. The effect of the SMA was captured by adding recovery stress term in the constitutive equation of the SMA composite plates. Values of the recovery stress of the SMA were determined using Brinson's model. Using the principle of virtual work and the total Lagrangian approach, the final finite element nonlinear governing equation for the post-buckling of SMA composite plates was derived. Buckling and post-buckling analyses were then conducted on the symmetric angle-ply and cross-ply SMA composite plates. The effect of several parameters such as the activation temperature, volume fraction, and the initial strain of the SMA on the post-buckling behavior of the SMA composite plates were studied. It was found that significant improvements in the post-buckling behavior for composite plates can be attained.

scholarly journals Development of Ferrous Shape Memory Alloy Showing Huge Superelasticity

Materia Japan ◽  
2011 ◽  
Vol 50 (8) ◽  
pp. 339-345 ◽  
Author(s):  
Yuuki Tanaka ◽  
Toshihiro Omori ◽  
Yoshiyuki Himuro ◽  
Yuji Sutou ◽  
Ryosuke Kainuma ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Ferrous Shape Memory Alloy

Deployable Process Analysis of Packaged SMP Sandwich Beam

2010 ◽  
Vol 123-125 ◽  
pp. 943-946 ◽  
Author(s):  
Zheng Fa Li ◽  
Zheng Dao Wang
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Sandwich Structure ◽  
Shape Recovery ◽  
Process Analysis ◽  
Sandwich Beam ◽  
Shape Memory Polymers ◽  
Recovery Stress ◽  
Recovery Response

Shape memory polymers own many advantages compared with traditional shape memory alloys or ceramics. In order to improve their shape recovery stress and realize a stable recovery response during the deployable process, the structure of SMP sandwich beam composed of two metallic skin and one SMP core is considered. The recovery behaviors of pure SMP and SMP beams reinforced by one-layer metallic skin are also discussed for comparison. The results confirm that the deployable properties of SMP matrix can be significantly improved by using sandwich structure.

scholarly journals Recovery Stress of TiNi Shape Memory Alloy. 2nd Report. Properties under Constant Maximum Strain.

1994 ◽  
Vol 60 (569) ◽  
pp. 120-125 ◽  
Author(s):  
Ping-Hua Lin ◽  
Hisaaki Tobushi ◽  
Kimio Kimura ◽  
Hiroyuki Iwanaga ◽  
Takeharu Hattori
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Maximum Strain ◽  
Recovery Stress ◽  
Constant Maximum
Sign in / Sign up

Export Citation Format

Share Document