scholarly journals Characteristics of Phase Transformation in Metallic Fine Particles (Martensitic transformation of Fe-Ni alloys, and ordering of CuAu and Cu3Au alloys)

1964 ◽  
Vol 5 (3) ◽  
pp. 135-141 ◽  
Author(s):  
Yoshichika Bando
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Fine Particles ◽  
Ni Alloys

Microstructure, Phase Transformation and Mechanical Property of Ni-Co-Mn-In Alloy Prepared by Spark Plasma Sintering

2015 ◽  
Vol 815 ◽  
pp. 222-226
Author(s):  
Bing Tian ◽  
Dong Cai Ren ◽  
Yun Xiang Tong ◽  
Feng Chen ◽  
Li Li ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Spark Plasma Sintering ◽  
Fine Particles ◽  
Sintered Alloy ◽  
Bulk Alloy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Powder Particles

The microstructure, phase transformation and mechanical property of Ni-Co-Mn-In alloy fabricated by powder metallurgical method were studied in the present investigation. The initial polycrystalline alloy was prepared by arc melting and then milled to fine particles, finally the powder particles were sintered by spark plasma sintering (SPS) method to make the bulk alloy with refined grains. The size of as-milled particles was much smaller than the grain size of the initial arc-melted alloy. The particles can be successfully densified to form a compact bulk by SPS. The initial arc-melted alloy presented a good martensitic transformation behavior, whereas the martensitic transformation of the as-sintered bulk alloy disappeared. The compressive strength and fracture strain of the as-sintered alloy greatly enhanced as compared to the initial arc-melted alloy due to the grain refinement and strengthening of grain boundaries.

Effect of Pre-Deformation and Ageing on Compressive Behavior of Ti-58.25wt%Ni Alloys at Room Temperature

2011 ◽  
Vol 197-198 ◽  
pp. 375-382
Author(s):  
Shi Chun Zhu ◽  
Xiao Feng Lu ◽  
Jian Ming Gong
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Transformation Temperature ◽  
Room Temperature ◽  
Dynamic Balance ◽  
Phase Transformation Temperature ◽  
Compressive Behavior ◽  
Range Analysis ◽  
Tooth Shape ◽  
Ni Alloys

In this paper, effect of pre-deformation and ageing on compressive behavior of Ti-58.25wt%Ni was investigated at room temperature. Through range analysis of three factors and three levels on transformation temperature measured by DSC, ageing at 673K enhanced phase transformation temperature obviously, the As temperature could reach 308.02K. Transformations of B2-B19’ and B2-R-B19’ appeared after the treatments. Saw tooth shape phenomenon on the loading curves indicating the typical martensitic transformation was also observed. Dynamic balance due to compatible action among various phase under increased load kept the slope of the loading curves constantly. Pre-deformation by 0.2% resulted in higher compressibility (4.9%), and ageing at 523K caused better recovery (95.4%).

Martensitic Transformation in Fe-Ni Alloys Nanostructured by Ball Milling

2008 ◽  
Vol 584-586 ◽  
pp. 955-959
Author(s):  
Victor V. Tcherdyntsev ◽  
S.M. Abdulhalikov ◽  
S.D. Kaloshkin ◽  
Leonid Y. Pustov ◽  
E.I. Estrin ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Mechanical Alloying ◽  
Solid Solutions ◽  
Ball Mill ◽  
Nanocrystalline Structure ◽  
Study Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys

Fe86Ni14 powder was prepared by mechanical alloying of elemental powders in a highenergy planetary ball mill. X-ray diffraction was used to investigate structure and phase constitution of samples, and thermomagnetic measurements were used to study phase transformation temperatures. MA led to formation of bcc α-Fe and fcc γ-Fe based solid solutions. Significant reduction of martensitic points for MA alloys was observed that was attributed both to nanocrystalline structure formation and samples impurity at milling.

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 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.

Transformation in Austenitic Stainless Steel Sheet under Different Loading Directions

2011 ◽  
Vol 473 ◽  
pp. 444-451
Author(s):  
A.H. van den Boogaard ◽  
J. Krauer ◽  
Pavel Hora
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Sheet Material ◽  
Stress Triaxiality ◽  
Austenitic Stainless Steels ◽  
Tensile Tests ◽  
Sheet Forming ◽  
Uniaxial Tensile ◽  
Reference Curve ◽  
Strain Relation

The stress-strain relation for austenitic stainless steels is based on 2 main contributions: work hardening and a phase transformation from austenite to martensite. The transformation is highly temperature dependent. In most models for phase transformation from austenite to martensite, the stress triaxiality plays an important role also. The sensitivity to triaxiality is often investigated based on uniaxial compression and tensile tests. To validate the common formulation for triaxiality dependence of the martensitic transformation, a series of experiments is performed with the Twente biaxial tester for sheet material. A number of deformation directions are prescribed between plane strain and simple shear. Uniaxial tensile tests were performed at different temperatures to get a temperature corrected reference curve for the martensite–strain relation. The current results for typical stress states in sheet forming do not show the dependency on the triaxiality that is given in literature. This means that for sheet forming simulations, changes in stress state affects the martensitic transformation less than expected from tension–compression experiments.

Effect of B2 Phase Transformation on the Mechanical Behavior of CuZr-Based Bulk Metallic Glass Composites

2017 ◽  
Vol 898 ◽  
pp. 672-678
Author(s):  
Ran Wei ◽  
Juan Tao ◽  
Shi Lei Liu ◽  
Guo Wen Sun ◽  
Shuai Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Lower Yield ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites ◽  
Lower Yield Strength ◽  
B2 Phase

The mechanical behavior of CuZr-based bulk metallic glass composites with different B2-CuZr phase transformation ability was investigated. The B2 phase transformation is conducive to enhance the mechanical properties of CuZr-based bulk metallic glass composites. The mechanical properties of the austenitic B2 phase specimens were also studied to understand the mechanism of phase transformation effect. It was found that the B2 phase with martensitic transformation exhibits lower yield strength and stronger work-hardening capability than the B2 phase without martensitic transformation. Thus, the phase transformation effect of B2-CuZr phase, accompanying with its lower yield strength and stronger work-hardening capability, is the main reason for the CuZr-based bulk metallic glass composites possess outstanding mechanical properties.

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