The Study of Ultrasonic Dynamic Elastic Modulus of TiNiFe Shape Memory Alloy in Heating Process

2009 ◽  
Vol 79-82 ◽  
pp. 1699-1702
Author(s):  
Xiao Peng Gao ◽  
Fu Shun Liu
Keyword(s):  
Phase Transformation ◽  
Elastic Modulus ◽  
Test Temperature ◽  
Martensite Transformation ◽  
Martensite Phase ◽  
Austenite Phase ◽  
Dynamic Elastic Modulus ◽  
Heating Process ◽  
Static Tensile ◽  
Tensile Elastic Modulus

The phase transformation characteristics, the dynamic elastic modulus and the static tensile elastic modulus of Ti50Ni47.5Fe2.5 alloy were investigated. It is found that, the two mutations in the dynamic elastic modulus is caused by reverse martensite phase transformation and austenite phase transformation respectively; Static tensile test can not reflect the intrinsic elastic modulus when the test temperature is close to martensite transformation temperature(Ms). The static elastic modulus and the dynamic elastic modulus have the same trend when the test temperature is enough higher than Ms.

Magnetoresistance of Ni50Mn37(Sn1-XInx)13 Alloys

2010 ◽  
Vol 168-169 ◽  
pp. 204-207 ◽  
Author(s):  
E.G. Gerasimov ◽  
S.M. Podgonykh ◽  
N.V. Mushnikov ◽  
V.P. Dyakina ◽  
T. Kanomata
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Electrical Resistivity ◽  
Phase Transformation ◽  
Martensite Transformation ◽  
Heusler Alloys ◽  
Magnetic Ordering ◽  
Large Change ◽  
Martensite Phase ◽  
Austenite Phase

Magnetic properties, electrical resistivity and magnetoresistance of the Ni50Mn37(Sn1 xInx)13 (x=0.2, 0.5) Heusler alloys were studied in magnetic fields up to 360 kOe in the temperature range 4-400 K. It was found that the alloys exhibit a martensite phase transformation at a critical temperature TM240 K for x=0.2 and TM350 K for x=0.5. The TM temperature is lower than the Curie temperature of the austenite phase TCA in the alloy with x=0.2 and is higher than TCA in the alloy with x=0.5. The spontaneous martensite transformation in both alloys is accompanied by a large change (~48%) of the electrical resistivity. A large negative magnetoresistance (~45%) is observed for the alloy with x=0.2 upon the field-induced martensite transformation. The analysis of the obtained results allows us to conclude that the large magnetoresistance in the alloys is mainly due to the changes in the crystal structure and only slightly depends on the changes in the magnetic ordering.

Influence of material parameters on 2D-martensitic transformation based on the phase-field finite-element method

2019 ◽  
Vol 116 (6) ◽  
pp. 614
Author(s):  
Li Chang ◽  
Gao Jingxiang ◽  
Zhang Dacheng ◽  
Chen Zhengwei ◽  
Han Xing
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Phase Field ◽  
Martensite Transformation ◽  
Transformation Process ◽  
Martensite Phase ◽  
Phase Field Method ◽  
Element Method

Obtaining an accurate microscopic representation of the martensitic transformation process is key to realizing the best performance of materials and is of great significance in the field of material design. Due to the martensite phase transformation is rapidly, the current experimental is hard to capture all the information in the Martensite phase transformation process. Combining the phase-field method with the finite-element method, a model of martensitic transformation from a metastable state to a steady state is established. The law of a single martensite nucleus during martensitic transformation is accurately described. By changing the key materials that affect martensite transformation and the phase-field parameters, the effects of the parameters on the single martensitic nucleation process are obtained. This study provides an important theoretical basis for effectively revealing the essence of martensite transformation and can determine effective ways to influence martensite transformation, obtain the optimal parameters and improve the mechanical properties of such materials.

scholarly journals The Effect of Drawing Deformation Rate Induced Inhomogeneous Local Distortion on Phase Transformation of 304H Stainless Wire

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1304
Author(s):  
Qinhua Xu ◽  
Zhixian Peng ◽  
Jianxin Zhu ◽  
Mingyang Li ◽  
Yong Zong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Heat Generation ◽  
Martensite Transformation ◽  
Local Strain ◽  
Cold Drawing ◽  
Element Distribution ◽  
Martensite Phase ◽  
Single Strain ◽  
Area Reduction

The micro/macro magnetic properties, local element distribution, martensite transformation, and mechanical properties of 304H stainless wires are determined for two cold drawing chains. Finite element simulations are used to analyse the local strain and heat generation. The results show that there is obvious inhomogeneity in the magnetic properties, strain/stress relationship, and strain-induced heat within the drawn wires. Comparing wires with the same total strain, a larger area reduction of previous drawing processes contributes to a higher volume of the martensite phase, while a smaller area reduction of the first process results in an inhibited phase transformation. A higher single strain in the first drawing process leads to additional heat generation at the subsurface of the wire, which would eventually retard the martensite transformation. The inhomogeneous deformation-induced differences in the grain size affect the stability of austenite and transform the final martensite.

scholarly journals Shock-induced Martensite phase transformation and its effects of metastable near β Ti-5553 titanium alloy

2018 ◽  
Vol 183 ◽  
pp. 03029
Author(s):  
Lin Wang ◽  
Anjin Liu ◽  
Huaxiang Dai ◽  
Feng Xu ◽  
Xinhua Min
Keyword(s):  
Phase Transformation ◽  
Microstructure Evolution ◽  
Martensite Transformation ◽  
Martensite Phase ◽  
Plate Impact ◽  
Loading Test ◽  
Gas Gun ◽  
Dynamic Loadings ◽  
Loading Tests ◽  
The Impact

In this paper, microstructure evolution and mechanic properties of metastable near β Ti-5553 alloy were investigated. SHPB, SHTB and light gas gun were employed to carry out the dynamic loadings. Microstructure evolution were characterized by OM, quantitative metallography and XRD. The experimental results demonstrated that stress-induced martensite transformation occur in metastable Ti-5553 alloy through SHPB, SHTB and plate impact loadings. In SHPB loading test, stress-induced martensite transformation is one of the methods that dissipate energy besides of adiabatic shear band, and also occur before ASB. In SHTB and SHPB+SHTB loading tests, the transformation amount of stressinduced martensite exhibit similar trend. In plate impact experiment, the content of martensite phase transformation increased with the impact velocity.

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

[P91] Thermodynamic and Kinetic Modeling of the Ferrite-Austenite Phase Transformation

Calphad ◽  
2015 ◽  
Vol 51 ◽  
pp. 402
Author(s):  
Dong An ◽  
Shiyan Pan ◽  
Qing Yu ◽  
Chen Lin ◽  
Ting Dai ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Kinetic Modeling ◽  
Austenite Phase

scholarly journals Microstructure and Phase Transformation Analysis of Ni50−xTi50Lax Shape Memory Alloys

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 345 ◽  
Author(s):  
Weiya Li ◽  
Chunwang Zhao
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Martensite Transformation ◽  
Transformation Behavior ◽  
Ni Content ◽  
Start Temperature

The microstructure and martensitic transformation behavior of Ni50−xTi50Lax (x = 0.1, 0.3, 0.5, 0.7) shape memory alloys were investigated experimentally. Results show that the microstructure of Ni50−xTi50Lax alloys consists of a near-equiatomic TiNi matrix, LaNi precipitates, and Ti2Ni precipitates. With increasing La content, the amounts of LaNi and Ti2Ni precipitates demonstrate an increasing tendency. The martensitic transformation start temperature increases gradually with increasing La content. The Ni content is mainly responsible for the change in martensite transformation behavior in Ni50−xTi50Lax alloys.

Sign in / Sign up

Export Citation Format

Share Document