Influence of Cold Work in the Elastic Modulus of the Ti-16.2Hf-24.8Nb-1Zr Alloy Characterized by Instrumented Nanoindentation

2009 ◽  
Vol 423 ◽  
pp. 113-118 ◽  
Author(s):  
Marta González ◽  
J. Peña ◽  
Jose Maria Manero ◽  
F.J. Gil
Keyword(s):  
Elastic Modulus ◽  
Shape Memory ◽  
Load Transfer ◽  
Cold Work ◽  
Elastic Response ◽  
Vacuum Arc ◽  
Damping Capacity ◽  
Heat Treated ◽  
Low Elastic Modulus ◽  
Cold Worked

Nowadays, β type Ti-based alloys have been developed for load transfer clinical applications due to their superelasticity, shape memory effect, low elastic modulus and high damping capacity [1]. These properties promote bone regeneration and make them promising candidates for being used in load transfer implantology. The objective of the present work is to achieve a material with shape memory properties and/or low elastic modulus. The influence of cold work on the thermoelastic martensitic transformation and elastic modulus of the Ti-16.2Hf-24.8Nb-1Zr alloy has been investigated to determine optimal conditions. The homogenized vacuum arc melted button was heat treated at 1100°C during 2 hours and quenched. Samples of each alloy were microstructurally and mechanically characterized after being cold rolled from 5 up to 95%. The elastic response for each condition was evaluated by instrumented nanoindentation by using a Berkovich tip and a spherical tip. A decrease in elastic modulus was observed when increasing the cold work percentage. The lowest value, 44 GPa, similar to that of cortical bone, was found in the 95% cold worked condition.

Effects of Hafnium, Heat Treatment and Cycling under an- Applied Stress on The Transformations of Cold Worked Niti-Based Shape Memory Alloys

1997 ◽  
Vol 481 ◽  
Author(s):  
Chen Zhan ◽  
Ralph H. Zee ◽  
Paul E. Thoma ◽  
John J. Boehm
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloys ◽  
Thermal Cycling ◽  
Shape Memory ◽  
Cold Work ◽  
Tensile Load ◽  
Axial Tensile ◽  
Heat Treated ◽  
Cold Worked ◽  
Reduction In Area

ABSTRACTThe effect of thermal cycling under a constant tensile load on the transformation temperatures (TTs) of NiTi-based shape memory alloys (SMAs) is investigated. Three SMAs are examined in this study: a near equiatomic binary Ni49Ti51 alloy and two ternary Ni49Ti51-xHfx alloys with 1 at% and 3 at% Hf. The SMAs are in the form of wires with 40% cold work (reduction in area) and heat treated between 300°C and 600°C. These SMA wires are thermally cycled between their martensite (M) and austenite (A) phases for 100 cycles under an axial tensile stress of 206.8MPa (30Ksi) in air. Results show that the effect of thermal cycling on the M and A TTs depends on heat treatment (HT) temperature and composition in a complex manner. For example, the M TT, of the binary NiTi SMA heat treated between 300°C and 450°C, increases during thermal cycling. However, with HT temperatures between 500°C and 600°C, the M TIT decreases slightly during thermal cycling. For the NiTi-based SMAs that contain 1 at% and 3 at% Hf, the M TT increases during thermal cycling for HT temperatures up to 500°C, and the M TT decreases during thermal cycling when heat treated at 600°C. These results are due to changes in internal stress and structure, such as dislocation density and arrangement, which are affected by HT temperature and thermal cycling. The influence of Hf content on the changes in the M and A TTs during thermal cycling is also shown.

Analysis on the Martensitic Transformation in the Ti-xNb Alloys Using a Phenomenological Theory

2007 ◽  
Vol 124-126 ◽  
pp. 1669-1672 ◽  
Author(s):  
Hi Won Jeong ◽  
Seung Eon Kim ◽  
Chang Yong Jo ◽  
Yong Tae Lee ◽  
Joong Kuen Park
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Martensitic Transformation ◽  
Shape Memory ◽  
Titanium Alloys ◽  
Martensitic Transformations ◽  
Phenomenological Theory ◽  
Transition Elements ◽  
Low Elastic Modulus ◽  
Diffraction Peaks

The titanium alloys containing the Nb transition elements have been investigated as the Ni-free shape memory and the biomedical alloys with a low elastic modulus. The mechanical properties of the alloys depended upon the meta-stable phases like the α`, α``, ω. To study the martensitic transformations from the β to α`` or α` the Ti-xNb (x=0 to 40 wt%) alloys were melted into the button type ingots using a VAR, and followed by the water-quenching after the soaking at 1000oC for 2hrs. The crystallography of the martensitic phases in the water-quenched alloys was analyzed using a XRD. The diffraction peaks of the orthorhombic martensites were identified by the crystallographic relationship with the bcc matrix. The lattice parameters of the orthorhombic martensites were varied continuously with the contents of the Nb elements. The martensitic transformations of the alloys were studied using the phenomenological theory of Bowles and Mackenzie.

The characterization of shape memory effect for low elastic modulus biomedical β-type titanium alloy

2010 ◽  
Vol 61 (5) ◽  
pp. 535-541 ◽  
Author(s):  
Liqiang Wang ◽  
Weijie Lu ◽  
Jining Qin ◽  
Fan Zhang ◽  
Di Zhang
Keyword(s):  
Titanium Alloy ◽  
Elastic Modulus ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Low Elastic Modulus

Synthesis and Characterisation of New Superelastic and Low Elastic Modulus Ti-Nb-X Alloys for Biomedical Application

2011 ◽  
Vol 409 ◽  
pp. 170-174
Author(s):  
A. Ramarolahy ◽  
Philippe Castany ◽  
Thierry Gloriant ◽  
Frédéric Prima ◽  
P. Laheurte ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Shape Memory ◽  
Biomedical Application ◽  
The Other ◽  
Alloying Element ◽  
Low Elastic Modulus ◽  
Superelastic Behavior ◽  
Good Biocompatibility

Ti-Nb based alloys are well known to their good mechanical properties, shape memory effect, superelasticity, as well as good biocompatibility. The Ti-24Nb (at%) binary alloy presents a shape memory behavior and low elastic modulus. Our study is focused on the improvement of their mechanical properties by adding a third alloying element (oxygen, nitrogen or silicon). Addition of 0.5 at% of N or O modifies drastically the mechanical behavior of Ti-24Nb alloy that exhibits superelastic behavior instead of shape memory one. On the other hand, addition of 0.5 at% of Si increased yield strength of the Ti-24Nb shape memory alloy.

scholarly journals Obtaining shape memory alloy thin layer using PLD technique

2014 ◽  
Vol 50 (1) ◽  
pp. 69-76 ◽  
Author(s):  
N. Cimpoeşu ◽  
S. Stanciu ◽  
P. Vizureanu ◽  
R. Cimpoeşu ◽  
Cristian Achiţei ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Deposition Process ◽  
Damping Capacity ◽  
Dynamic Mechanical Analyzer ◽  
Scanning Calorimetry ◽  
Material Microstructure ◽  
X Ray ◽  
Good Shape ◽  
Heat Treated

Copper-based shape memory alloy (SMA) was obtained through a classic melting method. The material was analyzed in heat treated and deformed states using scanning electrons microscopy (SEM), dilatometry (DIL), differential scanning calorimetry (DSC), dynamic mechanical analyzer (DMA) and energy dispersive X-ray analyze (EDAX) to establish the material microstructure, memory properties like martensitic transformation domain and rate or damping capacity. The material exhibits a good shape memory effect and high internal friction and it is proposed as target in a pulsed laser deposition (PLD) process for obtaining thin films. The deposition process is described in this paper through presented experimental results on the layer.

Study of New Multifunctional Shape Memory and Low Elastic Modulus Ni-Free Ti Alloys

2008 ◽  
Vol 39 (4) ◽  
pp. 742-751 ◽  
Author(s):  
M. Arciniegas ◽  
J.M. Manero ◽  
J. Peña ◽  
F.J. Gil ◽  
J.A. Planell
Keyword(s):  
Elastic Modulus ◽  
Shape Memory ◽  
Ti Alloys ◽  
Low Elastic Modulus

Sealing Performance of Pipe Flange Connections With Shape Memory Alloy Gaskets Under Internal Pressure

2004 ◽  
Author(s):  
Teruhisa Tatsuoka ◽  
Yoshio Takagi ◽  
Toshiyuki Sawa
Keyword(s):  
Elastic Modulus ◽  
Numerical Analysis ◽  
Low Temperature ◽  
Shape Memory ◽  
Strain Behavior ◽  
Sealing Performance ◽  
Low Elastic Modulus ◽  
Thermal Expansion Effect ◽  
Expansion Effect

Due to the long-term durability and the excellent resistance to aging degradation, metal gaskets are expected to give a longer life compared to conventional polymer gaskets. However, the nature of high elastic modulus of the metal reduces the sealing performance at interface. On the other hand, shape memory alloys (SMA) like nickel-titanium (Ni-Ti) alloy have a super elasticity and an excellent deformation capability with relatively low elastic modulus as a metal. Therefore, Ni-Ti SMA is expected to show an excellent performance as a gasket. In order to evaluate the applicability of Ni-Ti SMA to gasket, experimental and numerical analysis were conducted in this study. As an experimental evaluation, the new gasket constants and the tightness parameter proposed by PVRC (Pressure Vessel Research Council) were measured by the leakage tests. The constants and the tightness parameter of Ni-Ti SMA gasket were superior to those of aluminum gasket. The numerical analysis revealed that the clamping temperature highly affected on the performance of Ni-Ti SMA gasket because the stress-strain behavior of Ni-Ti SMA strongly depended on the temperature. Since the Ni-Ti SMA has a softer phase at low temperature, e.g. less than 11°C (As point), the flange connection initially clamped at low temperature showed a higher sealing performance. In addition, the heat cycle test with the cycle of the initial clamp temperature (0 or 20°C) to 40°C also suggested that the lower clamp temperature yielded a higher contact force due to the thermal expansion effect.

Improvement of Mechanical Properties and Transformation Behavior of NiTi Drawn Wires for Orthodontics Applications

2011 ◽  
Vol 378-379 ◽  
pp. 623-627
Author(s):  
Nakhon Noonai ◽  
Anak Khantachawana ◽  
Pongpan Kaewtatip ◽  
Julathep Kajornchaiyakul
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Shape Memory ◽  
Cold Work ◽  
Wire Drawing ◽  
Cross Sectional Area ◽  
Reduction Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
Heat Treated

NiTi shape memory alloy is widely used in dental applications such as orthodontics arch wire, mini screw implant, orthodontics spring, etc., because of its favorable superelasticity and shape memory effect. Wire drawing is a fundamental manufacturing process used for producing orthodontics arch wires. It is well known that cold-work occurred during wire drawing operation is also important to control mechanical properties and transformation temperature of NiTi wires. Thus, the purpose of this work is to study the effect of cold working by means of reduction ratio of cross -sectional area and heat-treatment temperatures on transformation and mechanical behavior of the drawn wires for utilized as orthodontic wires. The wire material used in this study is Ni51.4Ti48.6 (at%) alloy with various initial diameters with targeted wire diameter of 0.51mm (0.02 inch). The die for wire drawing is made of tungsten carbide which is inserted into a steel case. The dies were designed to have different reduction ratio of cross sectional area for 4 levels; 10%, 20%, 30% and 40%, respectively. The lubricant used in this study is sodium stearate powder. In order to investigate the influences of heat-treatment temperatures, the drawn wires are heat-treated at 400 °C and 600 °C for 3.6ks. The results showed that percentages of reduction of cross sectional area and heat-treatment temperature strongly affect mechanical properties and transformation temperatures. Superelasticity was confirmed in an alloy heat-treated at 400 °C. The results obtained can be used to determine the optimum properties of NiTi wire in order to utilized as orthodontics arch wires.

LUCEFIN GROUP C45U (1.1730)

Alloy Digest ◽  
2020 ◽  
Vol 69 (1) ◽  
Keyword(s):  
High Temperature ◽  
Cold Work ◽  
Hard Case ◽  
Medium Carbon ◽  
Hardened Zone ◽  
Temperature Performance ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Cold Work Tool Steel

Abstract Lucefin Group C45U is a medium-carbon, non-alloy cold-work tool steel. It is primarily used in the non-heat-treated condition. For special applications it is used in the quenched and tempered condition. Owing to its low hardenability, C45U develops a fully hardened zone that is relatively thin, even when quenched drastically. Thicker sections have a hard case over a tough core. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming and joining. Filing Code: TS-784. Producer or source: Lucefin S.p.A.

Sign in / Sign up

Export Citation Format

Share Document