Surface characteristics, mechanical properties, and cytocompatibility of oxygen plasma-implanted porous nickel titanium shape memory alloy

2006 ◽  
Vol 79A (1) ◽  
pp. 139-146 ◽  
Author(s):  
S.L. Wu ◽  
Paul K. Chu ◽  
X.M. Liu ◽  
C.Y. Chung ◽  
J.P.Y. Ho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Oxygen Plasma ◽  
Surface Characteristics ◽  
Nickel Titanium ◽  
Porous Nickel

An Overview of Powder Metallurgy (PM) Method for Porous Nickel Titanium Shape Memory Alloy (SMA)

2016 ◽  
Vol 1133 ◽  
pp. 269-274 ◽  
Author(s):  
Zulaila Abdullah ◽  
Rosliza Razali ◽  
Istikamah Subuki ◽  
Mohd Afian Omar ◽  
Muhammad Hussain Ismail
Keyword(s):  
Powder Metallurgy ◽  
Shape Memory Alloy ◽  
Porous Structure ◽  
Shape Memory ◽  
Manufacturing Process ◽  
Nickel Titanium ◽  
Porous Nickel ◽  
Porous Part ◽  
Biomedical Industry ◽  
The Common

NiTi is categorized as a Shape Memory Alloy (SMA) that has been commercially studied and used in biomedical industry due to two main unique properties, Pseudoelastic (PE) and Shape Memory Effect (SME). Combined with biomimetic properties to human bone, NiTi has the potential to be applied as implants by engineered manufacturing process. The common manufacturing by casting has some challenges in order to obtain intrinsic and miscellaneous design of NiTi parts leash to explore more using powder metallurgy (PM) method that expected to get the porous structure. This paper aims to provide an overview of processing NiTi by conventional PM method which could contribute in focusing porous part that suits for biomedical and implants.

Improved Electrical and Mechanical Properties of Niti/TiOx/PZT/TiOx Thin Film Heterostructures

2012 ◽  
Vol 185 ◽  
pp. 25-27 ◽  
Author(s):  
Nitin Choudhary ◽  
D.K. Kharat ◽  
Davinder Kaur
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
High Performance ◽  
Piezoelectric Properties ◽  
Nickel Titanium ◽  
Excellent Candidate ◽  
Dielectric And Piezoelectric Properties ◽  
Thin Film Devices

Nickel-titanium (NiTi) alloys are high-performance shape memory alloy actuator materials [1]. These alloys are metals possessing a memory, which can be triggered thermally or mechanically. Thin film of nickel-titanium shape memory alloy (SMA) is an excellent candidate for micro electric mechanical systems (MEMS). On the other hand, PZT is well known for its superior ferroelectric, dielectric and piezoelectric properties [2]. Integrating a ferroelectric (PZT) with ferroelastic (NiTi) material is technically interesting as the resulting heterostructure may then produce the properties associated with both of the materials and enhances the performance of MEMS based devices [3]. An important issue in the synthesis of NiTi/PZT hybrid heterostructure is the formation of appropriate crystalline phases of each material. The interdiffusions present at the interface of NiTi and PZT layer makes it difficult to obtain the optimal properties of both the components suitably at lower thickness values. With the miniaturization of active thin film devices, particularly for MEMS applications, it is desirable to obtain the best properties at lower thickness values. Therefore, in the present study, we have tried to lower the thickness of top NiTi films with the help of thin TiOx buffer layer between PZT and NiTi films. As expected, the excellent structural, electrical and mechanical properties of the NiTi/PZT heterostructure were achieved at lower thickness values.

scholarly journals Experimental and Numerical Analysis of the Mechanical Properties of a Pretreated Shape Memory Alloy Wire in a Self-Centering Steel Brace

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Bo Zhang ◽  
Sizhi Zeng ◽  
Fenghua Tang ◽  
Shujun Hu ◽  
Qiang Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Loading Rate ◽  
Effective Elastic Modulus ◽  
Maximum Energy ◽  
Numerical Results ◽  
Energy Dissipation Capacity

As a stimulus-sensitive material, the difference in composition, fabrication process, and influencing factors will have a great effect on the mechanical properties of a superelastic Ni-Ti shape memory alloy (SMA) wire, so the seismic performance of the self-centering steel brace with SMA wires may not be accurately obtained. In this paper, the cyclic tensile tests of a kind of SMA wire with a 1 mm diameter and special element composition were tested under multi-working conditions, which were pretreated by first tensioning to the 0.06 strain amplitude for 40 cycles, so the mechanical properties of the pretreated SMA wires can be simulated in detail. The accuracy of the numerical results with the improved model of Graesser’s theory was verified by a comparison to the experimental results. The experimental results show that the number of cycles has no significant effect on the mechanical properties of SMA wires after a certain number of cyclic tensile training. With the loading rate increasing, the pinch effect of the hysteresis curves will be enlarged, while the effective elastic modulus and slope of the transformation stresses in the process of loading and unloading are also increased, and the maximum energy dissipation capacity of the SMA wires appears at a loading rate of 0.675 mm/s. Moreover, with the initial strain increasing, the slope of the transformation stresses in the process of loading is increased, while the effective elastic modulus and slope of the transformation stresses in the process of unloading are decreased, and the maximum energy dissipation capacity appears at the initial strain of 0.0075. In addition, a good agreement between the test and numerical results is obtained by comparing with the hysteresis curves and energy dissipation values, so the numerical model is useful to predict the stress–strain relations at different stages. The test and numerical results will also provide a basis for the design of corresponding self-centering steel dampers.

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