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AN ATTEMPT TO IMPROVE AMBIENT DUCTILITY OF Ni_3Al BY COMPLEX ALLOYING WITH Mn AND B
Mn,B复合合金化对Ni3Al室温塑性的影响

YANG Wenying,LU Fanxiu,ZHANG Shouhua University of Science,Techhology Beijing,
杨文英
,吕反修,章守华

金属学报 , 1993,
Abstract: An improvement on the room temperature ductility of Ni_3Al was made by combination of microalloying and macroalloying with Mn and B. The elongation of Ni_3Al, after optimum alloying with B, is 14%, but that of complex alloyed one obtained up to 35%. Furthermore, this superiority of complex alloying seems to be only revealed with equivalent Al, i. e., %Mn+%Al, less than stoichoimetric content.
INFLUENCE OF Al ON DUCTILITY IMPROVEMENT BY B IN Ni_3Al ALLOYS
YANG Wenying LU Fanxiu ZHANG Shouhua University of Science,Technology Beijing,Beijing,China,
YANG Wenying LU Fanxiu ZHANG Shouhua University of Science and Technology Beijing
,Beijing,China

金属学报(英文版) , 1991,
Abstract: The “order-disorder” model was adopted to calculate the lattice vacancies related to the com-position change in Ni_3Al alloys.A great deal of vacancies,i.e.,the non-stoichiometric vacan-cies,may exist in the Ni_3Al alloys containing Al over stoichiometry,i.e.25 at.-%.This wasconfirmed by the positron annihilation technique.Therefore,the influence of Al content on theenhancing behaviour of B towards the ductility of Ni_3Al alloys can be understood by theinteraction of non-stoiehiometric vacancies and B atoms.
EFFECT OF Zr ON DUCTILITY OF CAST Ni_3 Al-BASE ALLOYS
ZHENG Zhi WU Weiwen GUO Jianting ZHU Yaoxiao Institute of Metal Research,Academia Sinica,Shenyang,China Institute of Metal Research,Academia Sinica,Shenyang,China,
ZHENG Zhi WU Weiwen GUO Jianting ZHU Yaoxiao Institute of Metal Research
,Academia Sinica,Shenyang,China Institute of Metal Research,Academia Sinica,Shenyang,China

金属学报(英文版) , 1992,
Abstract: Many compressive and tensile tests showed that the room temperature ductility of boron-freeNi_3Al alloy may be markedly improved by a moderate addition of Zr.The ductility of thestoichiometric Ni_3Al and even slightly enriched with Al,may be improved fairly between 400—600℃,which behaves much better if Zr is added together with B.However,the high tem-perature ductility of Ni_3Al alloys containing Cr may be significantly increased by Zr whichsegregates slightly along grain boundaries.Thus,the toughening mechanism of Zr alloyingseems to be different from that of B addition.
Atomistic Simulation of Interaction between Grain Boundary and Dislocations in Ni_3Al
Dongliang LIN Da CHEN Min LU,

材料科学技术学报 , 1993,
Abstract: The embedded atom type potentials and static relaxation method combined with a steepest decent computational technique have been used to simulate the interaction between the grain boundary (GB) and dislocations in Ni_3Al alloys.The focus has been placed on the energy feature of the interaction,the distortion of GB structural units,and the dislocation core structure near the GB.Im- plication has also been made on the results for the understanding of the mechanism responsible for B-enhanced ductility.
COMPUTER SIMULATION OF GRAIN BOUNDARY STRUCTURES IN Ni_3Al
LIN Dongliang,CHEN Da Shanghai Jiaotong University,Shanghai,China Professor,Deptof Materials Science,Shanghai Jiaotong University,Shanghai,China,
LIN Dongliang

金属学报(英文版) , 1990,
Abstract: The embedded atom type potentials and static relaxation method combined with steepest gra- dient computational technique have been used to simulate the grain boundary cohesive ener- gies,the distribution of electron density and stress field in the grain boundary,region,and oth- er related problems of100],110]and111]symmetric tilt grain boundaries in Ni_3Al with different grain boundary geometrical index and composition.Their relations with the segrega- tion or boron,behaviors or the grain boundary,and especially the stoichiometrical effect of B induced ductility have also been studied and discussed.
SIMULATIVE STUDY OF INTERACTION BETWEEN GRAIN BOUNDARIES AND DISLOCATIONS IN Ni_3Al
Ni3Al合金中晶界与位错交互作用的研究

CHEN Da,LU Min,LIN Dongliang Shanghai Jiao Tong University,
陈达
,陆敏,林栋梁

金属学报 , 1993,
Abstract: The embedded atom type potentials and static relaxation method combined with a steepest decent computational technique have been used to simulate the interaction be- tween the grain boundary and dislocations in Ni_3Al. The focus has been placed on the ener- getic features of the interaction, the distortion of grain boundary structural units and the dis- location core structures near the grain boundary. Implication has also been made on the re- sults for understanding of the mechanism responsible for boron-enhanced ductility.
ON DEGRADATION OF DUCTILITY INDUCED BY HYDROGEN IN MEDIUM CARBON STEELS
DU Jiaju TONG Shihua Institute of Solid State Physics,Academia Sinica,Hefei,China [Originally published in ACTA METALL SIN,
DU Jiaju TONG Shihua Institute of Solid State Physics
,Academia Sinica,Hefei,China [Originally published in ACTA METALL SIN

金属学报(英文版) , 1989,
Abstract: Optical microscope,SEM and IMMA investigation show that a strong interaction between hydrogen and calcium aluminate inclusions containing MgO may occur in medium carbon steels.This causes the hydrogen accumulating around the inclusions and reducing the ductility of the steel.
Detwinning-induced reduction in ductility of twinned copper nanowires
JunJie Zhang,FangDa Xu,YongDa Yan,Tao Sun
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5575-3
Abstract: Detwinning is a unique deformation mechanism of nanotwinned metals with twin lamellae thickness down to a few nanometers. In this work we investigate the impact of detwinning mechanism on the tensile ductility of twinned Cu nanowires containing high density of parallel twin boundaries by means of molecular dynamics simulations. Simulation results show that the fracture strain of twinned Cu nanowires has a strong dependence on twin boundary spacing, resulting from the competition between individual deformation modes. Particularly for the twinned Cu nanowires containing the thinnest twin lamellaes, the dominant detwinning mechanism leads to a significant reduction in the tensile ductility. It is found that detwinning originates from twin boundary migration, which is a result of the glide of lattice partial dislocations on the twin planes. This work advances our fundamental understanding of the twin boundary-related mechanical properties of twinned metallic nanowires.
EFFECT OF Zr ON DUCTILITY OF CAST Ni_3Al ALLOY
Zr对铸造Ni3Al合金塑性的影响

ZHENG Zhi,WU Weiwen,GUO Jianting,ZHU Yaoxiao Institute of Metal Research Academia Sinica,Shenyang Correspondent Professor,Institute of Metal Research,Academia Sinica,Shenyang,
郑志
,吴伟文,郭建亭,朱耀霄

金属学报 , 1992,
Abstract: 大量压缩和拉伸实验表明:在无硼Ni_3Al合金中加入适量的Zr可使其具有较好的室温塑性,Zr对Ni_3Al合金的韧化作用并不局限于富Ni的Ni_3Al合金,对Al含量略高于化学计量成分的Ni_3Al也有一定的韧化作用,而且Zr在晶界仅略有偏聚,因此,可以认为Zr对Ni_3Al合金的韧化机理与硼不同,Zr对改善中温脆性和提高高温塑性也都具有一定的效果
A Preliminary Investigation of Ductility-Enhancement Mechanism through In Situ Nanofibrillation in Thermoplastic Matrix Composites  [PDF]
Bhaskar Patham,M. P. Poornendu Thejaswini
Journal of Polymers , 2013, DOI: 10.1155/2013/424015
Abstract: A preliminary investigation of interrelationships between tensile stress-strain characteristics and morphology evolution during deformation is conducted on a commercially available thermoplastic composite with a low-surface-energy nanofibrillating poly(tetrafluoroethylene) (PTFE) additive. In this class of composites, the deformation-associated nanofibrillation of the low-surface-energy additive has been hypothesized to provide an additional dissipation mechanism, thereby enhancing the ductility of the composite. This class of composites offers potential for automotive light weighting in exterior and interior body and fascia applications; it is therefore of interest to investigate processing-structure-property interrelationships in these materials. This study specifically probes the interrelationships between the plastic deformation within the matrix and the fibrillation of the low-surface-energy additive; tensile tests are carried out at two different temperatures which are chosen so as to facilitate and suppress plastic deformation within the matrix polymer. Based on these preliminary investigations, it is noted that PTFE fibrillation acts synergistically with the ductile deformation of the matrix resin resulting in higher strains to failure of the composite; the results also suggest that the mechanism of fibrillation-assisted enhancement of strains to failure may not operate in the absence of matrix plasticity. 1. Introduction Thermoplastic matrix composites comprise an attractive class of materials holding high potential for light-weighting applications; these composites are typically designed to combine the ductility, toughness, and processability of thermoplastic matrices, and the stiffness, strength, thermo-mechanical, and other special functionalities of an additive material. Typical reinforcements that are added to polymeric matrices to enhance the thermo mechanical properties—for example, stiffness, strength, and heat-deflection temperature—include fibrous fillers (such as glass and carbon fibers), flakes and discs (such as talc), and nanofillers (such as nanoclay platelets). Typically, the addition of a stiffening reinforcement also leads to a compromise of the ductility of the composite; the resulting composite is rendered more brittle (with a lower strain to failure) compared to the unreinforced matrix. The loss of ductility relative to the unfilled polymer may be attributed to the rigid filler hindering certain degrees of freedom of the polymer to reconfigure its state upon being stressed. While structural members fabricated from
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