Papers by Author: Yan Dong Wang

Paper TitlePage

Authors: Hong Tao Liu, Guang Ai Sun, Yan Dong Wang, Bo Chen, Xiao Lin Wang, Qiang Tian
Abstract: The stress-induced martensitic transformation in Ni47Ti44Nb9 was examined using X-ray diffraction (XRD) during in situ uniaxial loading and unloading. A new martensitic (020) peak in XRD patterns is observed under strain from 10% to 12%. It indicates that the martensitic texture has reached the optimum orientation. After unloading, approximately 8% irreversible strain still remains. It is associated with the reorientation of martensites and the plastic deformation of the B2-phase. In addition, the deformed β-Nb particles would also reduce the driving force for the reverse transformation. The details of lattice-strain and shared applied stress (SAS) in the B2-phase and β-Nb phase are also discussed in this work.
Authors: E. Wen Huang, Yan Dong Wang, Bjørn Clausen, Michael L. Benson, Hahn Choo, Peter K. Liaw, Lee M. Pike
Authors: Gang Wang, Shi Ding Wu, Yan Dong Wang, Ya Ping Zong, Claude Esling, Liang Zuo
Abstract: Equal channel angular extrusion (ECAE) is an effective means of producing ultrafine-grained materials with extraordinary mechanical properties. Texture evolution and microstructure in pure copper single crystals processed by ECAE for up to five passes via route C are investigated to understand mechanisms of plastic deformation and grain refinement during ECAE. The experimental textures after the third pass ECAE process recovers that after one pass ECAE process. The main textures approaches a stable one after four passes of ECAE process via Route C while the intensity of main texture components decreases gradually. Local TEM-OIM measurements shows that grain subdivision in ECAE-processed samples occurs with the formation of many low angle grain boundaries.
Authors: Y.X. Cai, Y.D. Liu, Yi Nong Wang, Gang Wang, Yan Dong Wang, Fu Hui Wang, Liang Zuo
Abstract: The aim of this work is to investigate the relationship between the deformation microstructure and texture in cold rolled Interstitial Free (IF) steel sheets. In the present research, the cold rolled IF steel sheets with 10%-50% reductions are used to observe the characteristic microstructure and individual orientations by transmission electron microscopy (TEM) and SAED patterns. The experimental results on inter-granular strain homogeneity and dislocation wall formation are given in details in this paper. The results are explained by the analysis of crystallographic gliding and are helpful to improve the prediction of cold rolling textures.
Authors: Yu Dong Zhang, Chang Shu He, X. Zhao, Yan Dong Wang, Liang Zuo, Claude Esling
Abstract: The Weiss model is extended by substituting the molecular field coefficient lwith a short-range-ordering coefficient g valid around and above Tc. The temperature variations of susceptibility of fcc Fe are calculated with a band model. Based on the above models, the phase equilibrium diagram of Fe-C binary system under a magnetic field is calculated.
Authors: Dan Mo, Jun Cai, Ya Lin Li, Yan Dong Wang
Abstract: Using molecular dynamics method to study the cascade collision for the case of PKA(Primary Knock-on Atom) atoms at different distance from the grain boundary(GB) of iron chromium alloy. It is found that the PKA atoms at the GB will produce a large size cluster (size from 11 to 409 ) consisting of interstitial and vacancies, and many small clusters (number from 5 to 50). The size and number of the cluster depend heavily on PKA energy, while depend weakly on temperature. The PKA atom at distance of 1nm from the GB, sometimes produces large size defect clusters both inside and outside the GB region. When the PKA atom is at 1nm, 2nm and even 3nm, 4nm from the GB, the GB will effectively absorb the interstitial atoms. It is found that the atomic ratio of Cr-interstitial to total interstitial produced at the GB region is much less than one at outside of GB region.
Authors: Gang Wang, Chun Yan Wang, Zhe Chen, Wen Ru Zhao, Yan Dong Liu, Yan Dong Wang, Liang Zuo
Abstract: NiMnCoIn alloys are new-type magnetic shape memory alloys (MSMAs) in which a reversible magnetic-field-induced phase transformation was observed. They are ideal candidates of materials used in actuators and sensors. The polycrystalline NiMnCoIn alloys are generally brittle so that they can not be easily deformed into the shape applicable to actuators and sensors until now. In the present paper, the influence of hot deformation on the microstructure of Ni45Co5 Mn36.7In13.3 alloy was studied. The experimental results showed that second phase was observed after deformation at high temperature between 800~900 °C and at strain rate lower than 4×10-3s-1. The content of Co of second phase was higher than the matrix alloy, while the content of In was lower than the matrix alloy. It was determined by TEM measurements as γ phase with fcc structure which was popular in NiFeGa and NiMnGaCo alloys. It is possible to improve the ductility of Ni45Co5Mn36.7In13.3 alloy by control of amount and distribution of γ phase by hot deformation.
Authors: Yan Dong Wang, Ru Lin Peng, Jonathan Almer, Magnus Odén, Y.D. Liu, Liang Zuo
Abstract: Quantitative interpretations of the so-called non-linear lattice strain distributions observed in coatings and thin films are important not only for determining the macro- and microstress fields, but also for inferring the active mechanisms of grain interactions during various deposition processes. In this paper, we present a method, which determines simultaneously both the macro- and micro- stress fields in the coatings and thin films. This method is extended from the previous stress-orientation distribution function (SODF) analysis method, which has already been used for residual stress analysis in bulk materials subjected to rolling and fatigue deformation. The validity of analysis method is demonstrated through measurements of lattice strains by high-energy x-ray and analysis of grain-orientation-dependent stresses in a CrN coating.
Authors: Yan Dong Wang, Xiao Lin Wang, A.D. Stoica, Y.H. Sha, X. Zhao, Liang Zuo, James W. Richardson
Authors: Zeng Yong Chu, Yan Dong Wang, C.X. Feng, Yong Cai Song, Jun Wang, J.Y. Xiao, X.D. Li
Showing 1 to 10 of 29 Paper Titles