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81.
X.G.Zhou X.M.Zhao Y.B.Xu D.Wu 《金属学报(英文版)》2004,17(5):754-760
On the basis of phase transformation kinetics, the transformation of γ→α,P,B have been investigated through considering the effect of deformation. The calculation methods of volume fraction have also been given. Comparing with common method, the simulated results are in more agreement with experiment results. 相似文献
82.
L.Wang D.Xu B.C.CaiInformation Storage Research Center Shanghai Jiao Tong University Shanghai China Manuscript received September in revised form November 《金属学报(英文版)》2002,15(4):391-395
TiNi thin films were sputter-deposited on circular single-cry stal silicon substrates un-der various sputtering parameters. The crystal structure and residual stress of the as-deposited films were determined by X-ray diffraction and substrate-curvature method. The phenomenon of stress-suppressed martensitic transformation was observed. R is considered that the residual stresses in SMA thin films based on circular substrates act as balanced biaxial tensile stresses. The status of equilibrant delays the align-ment of self-accommodated variants and the volume shrinkage during the martensitic transformation. 相似文献
83.
XIE Changsheng SUN Peizhen ZHAO Jiansheng CHEN Yuqiu Huazhong University of Science Technology Wuhan China XIE Changsheng Associate Professor Department of Mechanical Engineering No. Huazhong University of Science Technology Wuhan China 《金属学报(英文版)》1990,3(1):52-57
The microstructures of Fe-Mn-Ni-Cr steels with medium carbon and the effect of alloy ele-ments on them have been investigated by means of X-ray diffraction quantitative phase ana-lyses,metallography and hardness tests.The volume fraction of martensite in steels quenchedat 1100℃ can be expressed as:f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V)Based on this expression,the quasi-equilibrium microstructure diagram has been obtained.Itis shown that the effect of Mn on the austenite stability is greater than that of Ni.The equiva-lent [Ni]=2.104Mn+Ni and equivalent [Cr]=Cr+Mo+V.The driving force for martensite transformation at M_s point has been calculated to hedrastically decreased by element Mn. 相似文献
84.
ZHU Xianfang ZHANG Lide Institute of Solid State Physics Academia Sinica Hefei China Research Assistant Institute of Solid State Physics Academia Sinica Hefei China 《金属学报(英文版)》1989,2(5):315-319
The characteristics of the low frequency internal friction and the modulus effect associatedwith the non-equilibrium spinodal pretransformation and the following discontinuous trans-formation was investigated in an as-quenched eutectiod Al-Zn alloy.It was observed that theloss of the stability in the lattice,which corresponded to the large-amplitude long-wavelengthstatic concentration wave in the non-equilibrium spinodal pretransformation,did not induceany effect of localized soft modulus.Although there are two aging internal friction peaks inphase transformation which correspond to the appearance and disappearance of the coherencyin spinodal pretransformation and the maximum of the interface area in the discontinuoustransformation respectively,the effect of localized soft modulus did not take place yet. 相似文献
85.
本文利用X射线定量相分析及金相观察和硬度测试,考察了中碳Fe-Mn-Ni-Cr钢的组织及合金元素的作用。建立了经1100℃淬火后的马氏体体积分数与合金成分的定量关系式; f_M~(1100)=162.643-15.482Mn-7.36Ni-4.286(Cr+Mo+V)并在此基础上给出了亚平衡组织图。结果表明,Mn稳定奥氏体的作用大于Ni的作用。Ni和Cr当量分别以[Ni]=2.104Mn+Ni,[Cr]=Cr+Mo+V表示。计算了M_S点处的马氏体相变驱动力,指出Mn具有强烈降低相变驱动力的作用。 相似文献
86.
Reaction rates in the Mg2Ni---H2 system are still unclear, although they are needed for the process/optimization of hydrogen storage reactors. In this article, the rates of hydrogen absorption and desorption of the magnesium nickel alloy were investigated at different pressures up to 2.0 MPa using a constant-temperature thermogravimetric method. The powder of the alloy was microencapsulated with copper to improve the alloy properties (such as cycling strength) as a pretreatment. In the experiments, weight changes of the smallest amount possible of samples were monitored with the help of an ultra-accurate thermobalance, in order to avoid changes of the sample temperature due to the heat of the reaction. The reaction curves obtained revealed unique dependence of temperature and pressure and influence of thermal hysterisis. It is also possible that hydrogen-absorption and-desorption rates of this hydrogen storage alloy are expressed by the rate equation of first-order reversible reaction. 相似文献
87.
借助经典体视学方法和“扩展组织”概念,定量研究了低碳硼钢620℃过冷奥氏体等温分解早期显微组织的演变路径。结果表明,母相晶界网络仍是低碳硼钢中α相形核长大的择优位置集合,择优顺序为晶粒棱(含隅)、晶界界面.棱集和隅集的位置饱和总是早于面集。钢中有效硼量对趋于饱和的路径和晶界面集的饱和迟早有显著影响。 相似文献
88.
89.
定向凝固法制备YBC超导体的若干材料学问题 总被引:5,自引:0,他引:5
讨论了定向凝固法制备YBCO超导体涉及的包晶转变与包晶反应,成分过冷,扩散控制生长模型,界面效应及定向凝固YBCO生长晶体学等问题。 相似文献
90.
TiAl 合金中的γ→α析出转变行为 总被引:1,自引:2,他引:1
研究了Ti-48Al和Ti-48Al—0.8B合金中的γ→α析出转变,分析了α析出相的生长形态、晶体学特征、生长动力学及α/γ相界面结构。结果显示α相从γ相中析出有两种方式:一种是从γ晶粒内沿{111},晶面以片状形貌析出,且α相与γ基体保持共格位向关系;另一种则是在γ晶界上通过不连续析出转变,以不规则的块状形貌析出,并向着晶界一侧与之无位向关系的γ晶粒内生长。添加0.8%(摩尔分数)B能显著降低γ晶粒内片状α析出相的形核率,并抑制α相生长。HREM分析表明:片状α相是在γ相的堆垛层错上形核,并通过“台阶-凸起-扭折”机制生长;α/γ相界面上复杂层错的存在及台阶形核率低是片状α相沿厚度方向生长缓慢的主要原因。 相似文献